Angiography, Digital Subtraction: A method of delineating blood vessels by subtracting a tissue background image from an image of tissue plus intravascular contrast material that attenuates the X-ray photons. The background image is determined from a digitized image taken a few moments before injection of the contrast material. The resulting angiogram is a high-contrast image of the vessel. This subtraction technique allows extraction of a high-intensity signal from the superimposed background information. The image is thus the result of the differential absorption of X-rays by different tissues.Subtraction Technique: Combination or superimposition of two images for demonstrating differences between them (e.g., radiograph with contrast vs. one without, radionuclide images using different radionuclides, radiograph vs. radionuclide image) and in the preparation of audiovisual materials (e.g., offsetting identical images, coloring of vessels in angiograms).Magnetic Resonance Angiography: Non-invasive method of vascular imaging and determination of internal anatomy without injection of contrast media or radiation exposure. The technique is used especially in CEREBRAL ANGIOGRAPHY as well as for studies of other vascular structures.Cerebral Angiography: Radiography of the vascular system of the brain after injection of a contrast medium.Angiography: Radiography of blood vessels after injection of a contrast medium.Intracranial Aneurysm: Abnormal outpouching in the wall of intracranial blood vessels. Most common are the saccular (berry) aneurysms located at branch points in CIRCLE OF WILLIS at the base of the brain. Vessel rupture results in SUBARACHNOID HEMORRHAGE or INTRACRANIAL HEMORRHAGES. Giant aneurysms (>2.5 cm in diameter) may compress adjacent structures, including the OCULOMOTOR NERVE. (From Adams et al., Principles of Neurology, 6th ed, p841)Coronary Angiography: Radiography of the vascular system of the heart muscle after injection of a contrast medium.Radiographic Image Enhancement: Improvement in the quality of an x-ray image by use of an intensifying screen, tube, or filter and by optimum exposure techniques. Digital processing methods are often employed.Imaging, Three-Dimensional: The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.Contrast Media: Substances used to allow enhanced visualization of tissues.Intracranial Arteriovenous Malformations: Congenital vascular anomalies in the brain characterized by direct communication between an artery and a vein without passing through the CAPILLARIES. The locations and size of the shunts determine the symptoms including HEADACHES; SEIZURES; STROKE; INTRACRANIAL HEMORRHAGES; mass effect; and vascular steal effect.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Embolization, Therapeutic: A method of hemostasis utilizing various agents such as Gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and INTRACRANIAL ARTERIOVENOUS MALFORMATIONS, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Carotid Artery, Internal: Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Aneurysm, Ruptured: The tearing or bursting of the weakened wall of the aneurysmal sac, usually heralded by sudden worsening pain. The great danger of a ruptured aneurysm is the large amount of blood spilling into the surrounding tissues and cavities, causing HEMORRHAGIC SHOCK.Central Nervous System Vascular Malformations: Congenital, inherited, or acquired abnormalities involving ARTERIES; VEINS; or venous sinuses in the BRAIN; SPINAL CORD; and MENINGES.Arterial Occlusive Diseases: Pathological processes which result in the partial or complete obstruction of ARTERIES. They are characterized by greatly reduced or absence of blood flow through these vessels. They are also known as arterial insufficiency.Carotid Stenosis: Narrowing or stricture of any part of the CAROTID ARTERIES, most often due to atherosclerotic plaque formation. Ulcerations may form in atherosclerotic plaques and induce THROMBUS formation. Platelet or cholesterol emboli may arise from stenotic carotid lesions and induce a TRANSIENT ISCHEMIC ATTACK; CEREBROVASCULAR ACCIDENT; or temporary blindness (AMAUROSIS FUGAX). (From Adams et al., Principles of Neurology, 6th ed, pp 822-3)Subarachnoid Hemorrhage: Bleeding into the intracranial or spinal SUBARACHNOID SPACE, most resulting from INTRACRANIAL ANEURYSM rupture. It can occur after traumatic injuries (SUBARACHNOID HEMORRHAGE, TRAUMATIC). Clinical features include HEADACHE; NAUSEA; VOMITING, nuchal rigidity, variable neurological deficits and reduced mental status.Tomography, Spiral Computed: Computed tomography where there is continuous X-ray exposure to the patient while being transported in a spiral or helical pattern through the beam of irradiation. This provides improved three-dimensional contrast and spatial resolution compared to conventional computed tomography, where data is obtained and computed from individual sequential exposures.Cerebral Veins: Veins draining the cerebrum.Iohexol: An effective non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures. Its low systemic toxicity is the combined result of low chemotoxicity and low osmolality.Salivary Gland Calculi: Calculi occurring in a salivary gland. Most salivary gland calculi occur in the submandibular gland, but can also occur in the parotid gland and in the sublingual and minor salivary glands.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Fluorescein Angiography: Visualization of a vascular system after intravenous injection of a fluorescein solution. The images may be photographed or televised. It is used especially in studying the retinal and uveal vasculature.Iopamidol: A non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiological procedures.Ultrasonography, Doppler, Duplex: Ultrasonography applying the Doppler effect combined with real-time imaging. The real-time image is created by rapid movement of the ultrasound beam. A powerful advantage of this technique is the ability to estimate the velocity of flow from the Doppler shift frequency.Observer Variation: The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).Constriction, Pathologic: The condition of an anatomical structure's being constricted beyond normal dimensions.Ultrasonography, Doppler, Color: Ultrasonography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region.Radiographic Image Interpretation, Computer-Assisted: Computer systems or networks designed to provide radiographic interpretive information.Radiography, Dental, Digital: A rapid, low-dose, digital imaging system using a small intraoral sensor instead of radiographic film, an intensifying screen, and a charge-coupled device. It presents the possibility of reduced patient exposure and minimal distortion, although resolution and latitude are inferior to standard dental radiography. A receiver is placed in the mouth, routing signals to a computer which images the signals on a screen or in print. It includes digitizing from x-ray film or any other detector. (From MEDLINE abstracts; personal communication from Dr. Charles Berthold, NIDR)Arteriovenous Malformations: Abnormal formation of blood vessels that shunt arterial blood directly into veins without passing through the CAPILLARIES. They usually are crooked, dilated, and with thick vessel walls. A common type is the congenital arteriovenous fistula. The lack of blood flow and oxygen in the capillaries can lead to tissue damage in the affected areas.Cerebral Arteries: The arterial blood vessels supplying the CEREBRUM.Vertebrobasilar Insufficiency: Localized or diffuse reduction in blood flow through the vertebrobasilar arterial system, which supplies the BRAIN STEM; CEREBELLUM; OCCIPITAL LOBE; medial TEMPORAL LOBE; and THALAMUS. Characteristic clinical features include SYNCOPE; lightheadedness; visual disturbances; and VERTIGO. BRAIN STEM INFARCTIONS or other BRAIN INFARCTION may be associated.X-Ray Intensifying Screens: Screens which absorb the energy in the x-ray beam that has penetrated the patient and convert this energy into a light pattern which has as nearly as possible the same information as the original x-ray beam. The more light a screen produces for a given input of x-radiation, the less x-ray exposure and thus shorter exposure time are needed to expose the film. In most film-screen systems, the film is sandwiched between two screens in a cassette so that the emulsion on each side is exposed to the light from its contiguous screen.Artifacts: Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.Carotid Artery Diseases: Pathological conditions involving the CAROTID ARTERIES, including the common, internal, and external carotid arteries. ATHEROSCLEROSIS and TRAUMA are relatively frequent causes of carotid artery pathology.Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.Gadolinium DTPA: A complex of gadolinium with a chelating agent, diethylenetriamine penta-acetic acid (DTPA see PENTETIC ACID), that is given to enhance the image in cranial and spinal MRIs. (From Martindale, The Extra Pharmacopoeia, 30th ed, p706)Anterior Cerebral Artery: Artery formed by the bifurcation of the internal carotid artery (CAROTID ARTERY, INTERNAL). Branches of the anterior cerebral artery supply the CAUDATE NUCLEUS; INTERNAL CAPSULE; PUTAMEN; SEPTAL NUCLEI; GYRUS CINGULI; and surfaces of the FRONTAL LOBE and PARIETAL LOBE.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Triiodobenzoic Acids: Triiodo-substituted derivatives of BENZOIC ACID.Carotid-Cavernous Sinus Fistula: An acquired or spontaneous abnormality in which there is communication between CAVERNOUS SINUS, a venous structure, and the CAROTID ARTERIES. It is often associated with HEAD TRAUMA, specifically basilar skull fractures (SKULL FRACTURE, BASILAR). Clinical signs often include VISION DISORDERS and INTRACRANIAL HYPERTENSION.Vertebral Artery: The first branch of the SUBCLAVIAN ARTERY with distribution to muscles of the NECK; VERTEBRAE; SPINAL CORD; CEREBELLUM; and interior of the CEREBRUM.Tibial Arteries: The anterior and posterior arteries created at the bifurcation of the popliteal artery. The anterior tibial artery begins at the lower border of the popliteus muscle and lies along the tibia at the distal part of the leg to surface superficially anterior to the ankle joint. Its branches are distributed throughout the leg, ankle, and foot. The posterior tibial artery begins at the lower border of the popliteus muscle, lies behind the tibia in the lower part of its course, and is found situated between the medial malleolus and the medial process of the calcaneal tuberosity. Its branches are distributed throughout the leg and foot.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Surgical Instruments: Hand-held tools or implements used by health professionals for the performance of surgical tasks.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Cranial Sinuses: Large endothelium-lined venous channels situated between the two layers of DURA MATER, the endosteal and the meningeal layers. They are devoid of valves and are parts of the venous system of dura mater. Major cranial sinuses include a postero-superior group (such as superior sagittal, inferior sagittal, straight, transverse, and occipital) and an antero-inferior group (such as cavernous, petrosal, and basilar plexus).Vasospasm, Intracranial: Constriction of arteries in the SKULL due to sudden, sharp, and often persistent smooth muscle contraction in blood vessels. Intracranial vasospasm results in reduced vessel lumen caliber, restricted blood flow to the brain, and BRAIN ISCHEMIA that may lead to hypoxic-ischemic brain injury (HYPOXIA-ISCHEMIA, BRAIN).Cerebrovascular Disorders: A spectrum of pathological conditions of impaired blood flow in the brain. They can involve vessels (ARTERIES or VEINS) in the CEREBRUM, the CEREBELLUM, and the BRAIN STEM. Major categories include INTRACRANIAL ARTERIOVENOUS MALFORMATIONS; BRAIN ISCHEMIA; CEREBRAL HEMORRHAGE; and others.Image Enhancement: Improvement of the quality of a picture by various techniques, including computer processing, digital filtering, echocardiographic techniques, light and ultrastructural MICROSCOPY, fluorescence spectrometry and microscopy, scintigraphy, and in vitro image processing at the molecular level.Basilar Artery: The artery formed by the union of the right and left vertebral arteries; it runs from the lower to the upper border of the pons, where it bifurcates into the two posterior cerebral arteries.Radiography, Interventional: Diagnostic and therapeutic procedures that are invasive or surgical in nature, and require the expertise of a specially trained radiologist. In general, they are more invasive than diagnostic imaging but less invasive than major surgery. They often involve catheterization, fluoroscopy, or computed tomography. Some examples include percutaneous transhepatic cholangiography, percutaneous transthoracic biopsy, balloon angioplasty, and arterial embolization.Ultrasonography, Doppler, Transcranial: A non-invasive technique using ultrasound for the measurement of cerebrovascular hemodynamics, particularly cerebral blood flow velocity and cerebral collateral flow. With a high-intensity, low-frequency pulse probe, the intracranial arteries may be studied transtemporally, transorbitally, or from below the foramen magnum.Injections, Intra-Arterial: Delivery of drugs into an artery.Arteriovenous Fistula: An abnormal direct communication between an artery and a vein without passing through the CAPILLARIES. An A-V fistula usually leads to the formation of a dilated sac-like connection, arteriovenous aneurysm. The locations and size of the shunts determine the degree of effects on the cardiovascular functions such as BLOOD PRESSURE and HEART RATE.Aneurysm: Pathological outpouching or sac-like dilatation in the wall of any blood vessel (ARTERIES or VEINS) or the heart (HEART ANEURYSM). It indicates a thin and weakened area in the wall which may later rupture. Aneurysms are classified by location, etiology, or other characteristics.Sialography: Radiography of the SALIVARY GLANDS or ducts following injection of contrast medium.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Myelography: X-ray visualization of the spinal cord following injection of contrast medium into the spinal arachnoid space.Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Circle of Willis: A polygonal anastomosis at the base of the brain formed by the internal carotid (CAROTID ARTERY, INTERNAL), proximal parts of the anterior, middle, and posterior cerebral arteries (ANTERIOR CEREBRAL ARTERY; MIDDLE CEREBRAL ARTERY; POSTERIOR CEREBRAL ARTERY), the anterior communicating artery and the posterior communicating arteries.Cerebral Revascularization: Microsurgical revascularization to improve intracranial circulation. It usually involves joining the extracranial circulation to the intracranial circulation but may include extracranial revascularization (e.g., subclavian-vertebral artery bypass, subclavian-external carotid artery bypass). It is performed by joining two arteries (direct anastomosis or use of graft) or by free autologous transplantation of highly vascularized tissue to the surface of the brain.Renal Artery: A branch of the abdominal aorta which supplies the kidneys, adrenal glands and ureters.Iothalamate Meglumine: A radiopaque medium used for urography, angiography, venography, and myelography. It is highly viscous and binds to plasma proteins.Carotid Arteries: Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery.Intracranial Arteriosclerosis: Vascular diseases characterized by thickening and hardening of the walls of ARTERIES inside the SKULL. There are three subtypes: (1) atherosclerosis with fatty deposits in the ARTERIAL INTIMA; (2) Monckeberg's sclerosis with calcium deposits in the media and (3) arteriolosclerosis involving the small caliber arteries. Clinical signs include HEADACHE; CONFUSION; transient blindness (AMAUROSIS FUGAX); speech impairment; and HEMIPARESIS.Neurosurgical Procedures: Surgery performed on the nervous system or its parts.Salivary Gland DiseasesRadiation Dosage: The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Radiography, Bitewing: Technique involving the passage of X-rays through oral structures to create a film record while a central tab or wing of dental X-ray film is being held between upper and lower teeth.Carotid Artery, External: Branch of the common carotid artery which supplies the exterior of the head, the face, and the greater part of the neck.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Moyamoya Disease: A noninflammatory, progressive occlusion of the intracranial CAROTID ARTERIES and the formation of netlike collateral arteries arising from the CIRCLE OF WILLIS. Cerebral angiogram shows the puff-of-smoke (moyamoya) collaterals at the base of the brain. It is characterized by endothelial HYPERPLASIA and FIBROSIS with thickening of arterial walls. This disease primarily affects children but can also occur in adults.Radionuclide Angiography: The measurement of visualization by radiation of any organ after a radionuclide has been injected into its blood supply. It is used to diagnose heart, liver, lung, and other diseases and to measure the function of those organs, except renography, for which RADIOISOTOPE RENOGRAPHY is available.Vascular Patency: The degree to which BLOOD VESSELS are not blocked or obstructed.Phantoms, Imaging: Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.Collateral Circulation: Maintenance of blood flow to an organ despite obstruction of a principal vessel. Blood flow is maintained through small vessels.Aortography: Radiographic visualization of the aorta and its branches by injection of contrast media, using percutaneous puncture or catheterization procedures.Ultrasonography: The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.Angioplasty, Balloon: Use of a balloon catheter for dilation of an occluded artery. It is used in treatment of arterial occlusive diseases, including renal artery stenosis and arterial occlusions in the leg. For the specific technique of BALLOON DILATION in coronary arteries, ANGIOPLASTY, BALLOON, CORONARY is available.Gadolinium: Gadolinium. An element of the rare earth family of metals. It has the atomic symbol Gd, atomic number 64, and atomic weight 157.25. Its oxide is used in the control rods of some nuclear reactors.Sialadenitis: INFLAMMATION of salivary tissue (SALIVARY GLANDS), usually due to INFECTION or injuries.Immediate Dental Implant Loading: Endosseous dental implantation where implants are fitted with an abutment or where an implant with a transmucosal coronal portion is used immediately (within 1 week) after the initial extraction. Conventionally, the implantation is performed in two stages with more than two months in between the stages.Ischemic Attack, Transient: Brief reversible episodes of focal, nonconvulsive ischemic dysfunction of the brain having a duration of less than 24 hours, and usually less than one hour, caused by transient thrombotic or embolic blood vessel occlusion or stenosis. Events may be classified by arterial distribution, temporal pattern, or etiology (e.g., embolic vs. thrombotic). (From Adams et al., Principles of Neurology, 6th ed, pp814-6)Ultrasonography, Doppler: Ultrasonography applying the Doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. (Stedman, 25th ed)Time Factors: Elements of limited time intervals, contributing to particular results or situations.Popliteal Artery: The continuation of the femoral artery coursing through the popliteal fossa; it divides into the anterior and posterior tibial arteries.Cerebrospinal Fluid Rhinorrhea: Discharge of cerebrospinal fluid through the nose. Common etiologies include trauma, neoplasms, and prior surgery, although the condition may occur spontaneously. (Otolaryngol Head Neck Surg 1997 Apr;116(4):442-9)Endarterectomy: Surgical excision, performed under general anesthesia, of the atheromatous tunica intima of an artery. When reconstruction of an artery is performed as an endovascular procedure through a catheter, it is called ATHERECTOMY.Brain Ischemia: Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Celiac Artery: The arterial trunk that arises from the abdominal aorta and after a short course divides into the left gastric, common hepatic and splenic arteries.Preoperative Care: Care given during the period prior to undergoing surgery when psychological and physical preparations are made according to the special needs of the individual patient. This period spans the time between admission to the hospital to the time the surgery begins. (From Dictionary of Health Services Management, 2d ed)Renal Artery Obstruction: Narrowing or occlusion of the RENAL ARTERY or arteries. It is due usually to ATHEROSCLEROSIS; FIBROMUSCULAR DYSPLASIA; THROMBOSIS; EMBOLISM, or external pressure. The reduced renal perfusion can lead to renovascular hypertension (HYPERTENSION, RENOVASCULAR).Coronary Artery Disease: Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.Cavernous Sinus: An irregularly shaped venous space in the dura mater at either side of the sphenoid bone.Fluoroscopy: Production of an image when x-rays strike a fluorescent screen.Organometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)Equipment Design: Methods of creating machines and devices.Femoral Artery: The main artery of the thigh, a continuation of the external iliac artery.Radiography, Dual-Energy Scanned Projection: A method of producing a high-quality scan by digitizing and subtracting the images produced by high- and low-energy x-rays.Coronary Stenosis: Narrowing or constriction of a coronary artery.Ischemia: A hypoperfusion of the BLOOD through an organ or tissue caused by a PATHOLOGIC CONSTRICTION or obstruction of its BLOOD VESSELS, or an absence of BLOOD CIRCULATION.Iliac Artery: Either of two large arteries originating from the abdominal aorta; they supply blood to the pelvis, abdominal wall and legs.False Negative Reactions: Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Cerebral Infarction: The formation of an area of NECROSIS in the CEREBRUM caused by an insufficiency of arterial or venous blood flow. Infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., INFARCTION, ANTERIOR CEREBRAL ARTERY), and etiology (e.g., embolic infarction).Arteries: The vessels carrying blood away from the heart.False Positive Reactions: Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)Peripheral Vascular Diseases: Pathological processes involving any one of the BLOOD VESSELS in the vasculature outside the HEART.Single-Blind Method: A method in which either the observer(s) or the subject(s) is kept ignorant of the group to which the subjects are assigned.Middle Cerebral Artery: The largest of the cerebral arteries. It trifurcates into temporal, frontal, and parietal branches supplying blood to most of the parenchyma of these lobes in the CEREBRAL CORTEX. These are the areas involved in motor, sensory, and speech activities.Vascular Surgical Procedures: Operative procedures for the treatment of vascular disorders.Aneurysm, False: Not an aneurysm but a well-defined collection of blood and CONNECTIVE TISSUE outside the wall of a blood vessel or the heart. It is the containment of a ruptured blood vessel or heart, such as sealing a rupture of the left ventricle. False aneurysm is formed by organized THROMBUS and HEMATOMA in surrounding tissue.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Libraries, Digital: Libraries in which a major proportion of the resources are available in machine-readable format, rather than on paper or MICROFORM.ROC Curve: A graphic means for assessing the ability of a screening test to discriminate between healthy and diseased persons; may also be used in other studies, e.g., distinguishing stimuli responses as to a faint stimuli or nonstimuli.Catheterization: Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.Endarterectomy, Carotid: The excision of the thickened, atheromatous tunica intima of a carotid artery.Equipment Failure Analysis: The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.Image Interpretation, Computer-Assisted: Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.Models, Anatomic: Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.Vascular Diseases: Pathological processes involving any of the BLOOD VESSELS in the cardiac or peripheral circulation. They include diseases of ARTERIES; VEINS; and rest of the vasculature system in the body.Recurrence: The return of a sign, symptom, or disease after a remission.Blood Vessel Prosthesis: Device constructed of either synthetic or biological material that is used for the repair of injured or diseased blood vessels.Technetium: The first artificially produced element and a radioactive fission product of URANIUM. Technetium has the atomic symbol Tc, atomic number 43, and atomic weight 98.91. All technetium isotopes are radioactive. Technetium 99m (m=metastable) which is the decay product of Molybdenum 99, has a half-life of about 6 hours and is used diagnostically as a radioactive imaging agent. Technetium 99 which is a decay product of technetium 99m, has a half-life of 210,000 years.Leg: The inferior part of the lower extremity between the KNEE and the ANKLE.Rotation: Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Indocyanine Green: A tricarbocyanine dye that is used diagnostically in liver function tests and to determine blood volume and cardiac output.Cerebral Hemorrhage: Bleeding into one or both CEREBRAL HEMISPHERES including the BASAL GANGLIA and the CEREBRAL CORTEX. It is often associated with HYPERTENSION and CRANIOCEREBRAL TRAUMA.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Tomography, Emission-Computed, Single-Photon: A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.Coronary Disease: An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.Photography: Method of making images on a sensitized surface by exposure to light or other radiant energy.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Radiology Information Systems: Information systems, usually computer-assisted, designed to store, manipulate, and retrieve information for planning, organizing, directing, and controlling administrative activities associated with the provision and utilization of radiology services and facilities.Multidetector Computed Tomography: Types of spiral computed tomography technology in which multiple slices of data are acquired simultaneously improving the resolution over single slice acquisition technology.Radionuclide Imaging: The production of an image obtained by cameras that detect the radioactive emissions of an injected radionuclide as it has distributed differentially throughout tissues in the body. The image obtained from a moving detector is called a scan, while the image obtained from a stationary camera device is called a scintiphotograph.Lower Extremity: The region of the lower limb in animals, extending from the gluteal region to the FOOT, and including the BUTTOCKS; HIP; and LEG.Coronary Vessels: The veins and arteries of the HEART.Stroke: A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)Sodium Pertechnetate Tc 99m: A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in the gastrointestinal system, cardiovascular and cerebral circulation, brain, thyroid, and joints.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Radiography, Thoracic: X-ray visualization of the chest and organs of the thoracic cavity. It is not restricted to visualization of the lungs.Pulmonary Artery: The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.Signal Processing, Computer-Assisted: Computer-assisted processing of electric, ultrasonic, or electronic signals to interpret function and activity.Carotid Artery, Common: The two principal arteries supplying the structures of the head and neck. They ascend in the neck, one on each side, and at the level of the upper border of the thyroid cartilage, each divides into two branches, the external (CAROTID ARTERY, EXTERNAL) and internal (CAROTID ARTERY, INTERNAL) carotid arteries.X-Ray Film: A film base coated with an emulsion designed for use with x-rays.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Thallium: A heavy, bluish white metal, atomic number 81, atomic weight [204.382; 204.385], symbol Tl.Arteriosclerosis: Thickening and loss of elasticity of the walls of ARTERIES of all sizes. There are many forms classified by the types of lesions and arteries involved, such as ATHEROSCLEROSIS with fatty lesions in the ARTERIAL INTIMA of medium and large muscular arteries.Fundus Oculi: The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)Acute Disease: Disease having a short and relatively severe course.Diagnostic Imaging: Any visual display of structural or functional patterns of organs or tissues for diagnostic evaluation. It includes measuring physiologic and metabolic responses to physical and chemical stimuli, as well as ultramicroscopy.Ultrasonography, Interventional: The use of ultrasound to guide minimally invasive surgical procedures such as needle ASPIRATION BIOPSY; DRAINAGE; etc. Its widest application is intravascular ultrasound imaging but it is useful also in urology and intra-abdominal conditions.Telepathology: Transmission and interpretation of tissue specimens via remote telecommunication, generally for the purpose of diagnosis or consultation but may also be used for continuing education.

Combined carotid endarterectomy and coronary artery bypass graft. (1/1139)

Atherosclerosis is a generalized disease which afflicts a considerable number of patients in both the carotid and coronary arteries. Although the risk of stroke or death use to combined carotid endarterectomy (CEA) and coronary artery bypass graft (CABG) is thought to be higher than that of each individual operation, the combined procedure is generally preferred over staged operations to treat such patients. We performed the combined procedure safely with the aid of intraoperative portable digital subtraction angiography (DSA). This report describes our experience with the operative strategy of simultaneous CEA and CABG. Ninety CEA and 404 CABG were carried out between January 1989 and December 1997. A total of six patients received the combined procedure with the aid of intraoperative DSA; they were studied retrospectively. Postoperative mortality and morbidity after the combined procedure was 0%. In the combined procedure, neurological complications are difficult to detect after CEA because the patient must be maintained under general anesthesia and extracorporeal circulation during the subsequent CABG. However, intraoperative DSA can confirm patency of the internal carotid artery and absence of flap formation after CEA, and the CABG can be performed safely. Intraoperative portable DSA between CEA and CABG is helpful in preventing perioperative stroke in the combined procedure.  (+info)

Popliteal artery occlusion as a late complication of liquid acrylate embolization for cerebral vascular malformation. (2/1139)

Occlusion of arteriovenous malformations of the brain (BAVMs) by means of an endovascular approach with liquid acrylate glue is an established treatment modality. The specific hazards of this procedure are related to the central nervous system. In the case of unexpectedly rapid polymerization of the cyanoacrylate glue and adhesion of the delivering microcatheter to the BAVM, severing the catheter at the site of vascular access is considered an acceptable and safe management. We present a unique complication related to this technique that has not been described yet. Fragmentation and migration of the microcatheter, originally left in place, had caused popliteal artery occlusion, which required saphenous vein interposition, in a 25-year-old man. Suggestions for avoiding this complication are discussed.  (+info)

Factors influencing the development of vein-graft stenosis and their significance for clinical management. (3/1139)

OBJECTIVES: To assess the influence of clinical and graft factors on the development of stenotic lesions. In addition the implications of any significant correlation for duplex surveillance schedules or surgical bypass techniques was examined. PATIENTS AND METHODS: In a prospective three centre study, preoperative and peroperative data on 300 infrainguinal autologous vein grafts was analysed. All grafts were monitored by a strict duplex surveillance program and all received an angiogram in the first postoperative year. A revision was only performed if there was evidence of a stenosis of 70% diameter reduction or greater on the angiogram. RESULTS: The minimum graft diameter was the only factor correlated significantly with the development of a significant graft stenosis (PSV-ratio > or = 2.5) during follow-up (p = 0.002). Factors that correlated with the development of event-causing graft stenosis, associated with revision or occlusion, were minimal graft diameter (p = 0.001), the use of a venovenous anastomosis (p = 0.005) and length of the graft (p = 0.025). Multivariate regression analysis revealed that the minimal graft diameter was the only independent factor that significantly correlated with an event-causing graft stenosis (p = 0.009). The stenosis-free rates for grafts with a minimal diameter < 3.5 mm, between 3.5-4.5 and > or = 4.5 mm were 40%, 58% and 75%, respectively (p = < 0.05). Composite vein and arm-vein grafts with minimal diameters > or = 3.5 mm were compared with grafts which consisted of a single uninterrupted greater saphenous vein with a minimal diameter of < 3.5 mm. One-year secondary patency rates in these categories were of 94% and 76%, respectively (p = 0.03). CONCLUSIONS: A minimal graft diameter < 3.5 mm was the only factor that significantly correlated with the development of a graft-stenosis. However, veins with larger diameters may still develop stenotic lesions. Composite vein and arm-vein grafts should be used rather than uninterrupted small caliber saphenous veins.  (+info)

Bilateral vertebral artery occlusion following cervical spine trauma--case report. (4/1139)

A 41-year-old female presented with a rare case of bilateral vertebral artery occlusion following C5-6 cervical spine subluxation after a fall of 30 feet. Digital subtraction angiography showed occlusion of the bilateral vertebral arteries. Unlocking of the facet joint, posterior wiring with iliac crest grafting, and anterior fusion were performed. The patient died on the 3rd day after the operation. This type of injury has a grim prognosis with less than a third of the patients achieving a good outcome.  (+info)

Evaluation of cerebral aneurysms with high-resolution MR angiography using a section-interpolation technique: correlation with digital subtraction angiography. (5/1139)

BACKGROUND AND PURPOSE: The objective was to evaluate the results of high-resolution, fast-speed, section-interpolation MR angiography and digital subtraction angiography (DSA), thereby examining the potential use of a primary noninvasive screening test for intracranial aneurysms. METHODS: The images were obtained in 39 cerebral aneurysmal lesions from 30 patients with a time-of-flight MR angiographic technique using a 1.5-T superconducting MR system. The total image volume was divided into four slabs, with 48 partitions each. To save time, only 24 phase-encoded steps were measured and interpolated to 48. The parameters used included 30/6.4 (TR/TE), a flip angle of 25 degrees , a 160x512 matrix, a field of view of 150x200, 7 minutes 42 seconds of scan time, an effective thickness of 0.7 mm, and an entire thickness of 102.2 mm. Maximum intensity projection was used for the image analysis, and a multiplanar reconstruction technique was used for patients with intracranial aneurysms. RESULTS: Among 39 intracranial aneurysmal lesions in 30 patients, 21 were ruptured and 18 were unruptured. Twelve lesions were less than 2 mm in size, 12 were 3 to 5 mm, 12 were 6 to 9 mm, and three were larger than 10 mm. At initial examinations, 38 of 39 aneurysmal lesions were detected by both MR angiography and DSA, with 97% sensitivity. In confirming aneurysms in neck and parent vessels, multiplanar reconstruction was successful in detecting all 39 aneurysms, whereas MR angiography was successful in detecting 27 (69%) and DSA was successful in detecting 32 (82%) of the lesions. CONCLUSION: High-resolution MR angiography with a section-interpolation technique showed equal results to those of DSA for the detection of intracranial aneurysms and may be used as a primary noninvasive screening test. In the evaluation of aneurysms in neck and parent vessels, the concurrent use of MR angiography and multiplanar reconstruction was far superior to the use of either MR angiography or DSA alone.  (+info)

Twinkling artifact on intracerebral color Doppler sonography. (6/1139)

Transcranial Doppler sonography shows potential as a noninvasive technique for long-term follow-up of treated intracranial saccular aneurysms. This technical note describes a color Doppler artifact related to microcoil architecture that might represent a potential pitfall in transcranial Doppler sonographic evaluation of aneurysmal cavity thrombosis, since it may be wrongly interpreted as residual flow or aneurysmal cavity recanalization.  (+info)

Cerebral veins: comparative study of CT venography with intraarterial digital subtraction angiography. (7/1139)

BACKGROUND AND PURPOSE: Our objective was to compare the reliability of CT venography with intraarterial digital subtraction angiography (DSA) in imaging cerebral venous anatomy and pathology. METHODS: In 25 consecutive patients, 426 venous structures were determined as present, partially present, or absent by three observers evaluating CT multiplanar reformatted (MPR) and maximum intensity projection (MIP) images. These results were compared with the results from intraarterial DSA and, in a second step, with the results of an intraobserver consensus. In addition, pathologic conditions were described. RESULTS: Using DSA as the standard of reference, MPR images had an overall sensitivity of 95% (specificity, 19%) and MIP images a sensitivity of 80% (specificity, 44%) in depicting the cerebral venous anatomy. On the basis of an intraobserver consensus including DSA, MPR, and MIP images (415 vessels present), the sensitivity/specificity was 95%/91% for MPR, 90%/100% for DSA, and 79%/91% for MIP images. MPR images were superior to DSA images in showing the cavernous sinus, the inferior sagittal sinus, and the basal vein of Rosenthal. Venous occlusive diseases were correctly recognized on both MPR and MIP images. Only DSA images provided reliable information of invasion of a sinus by an adjacent meningioma. CONCLUSION: CT venography proved to be a reliable method to depict the cerebral venous structures. MPR images were superior to MIP images.  (+info)

A persistent pharyngohyostapedial artery: embryologic implications. (8/1139)

A 3-year-old child was examined because of otorrhagia. CT scans showed an unusual vessel, confirmed by angiography, related to a persistent pharyngohyostapedial artery. This embryonic persistent artery associated with the normal internal carotid artery would explain the "duplication" aspect of the internal carotid artery.  (+info)

Comparisons between digital subtraction angiography and conventional angiography have frequently been made in the radiologic literature, and the high quality and several advantages of the former have been reported. In this study, 101 patients with intracranial aneurysms were examined only by intraarterial digital subtraction angiography; no conventional angiography was used. High-quality images were consistently obtained, facilitating an accurate and definitive diagnosis of intracranial aneurysm. Magnification radiography and stereography using intraarterial digital subtraction angiography were done to obtain a more precise diagnosis. Five small intracranial aneurysms with diameters of 1.0 to 2.0 mm could be detected. The procedure was considered to be as reliable and as safe as conventional angiography, used previously. Important advantages of intraarterial digital subtraction angiography include reduced procedural time and decreased contrast agent burden, factors that will ensure broader ...
TY - JOUR. T1 - Intra-arterial digital subtraction angiography through the ear artery for experimental aneurysm imaging. AU - Ding, Y. H.. AU - Dai, D.. AU - Danielson, M. A.. AU - Kadirvel, R.. AU - Lewis, D. A.. AU - Cloft, H. J.. AU - Kallmes, David F.. PY - 2006/9/1. Y1 - 2006/9/1. N2 - Digital subtraction angiography through the central artery of the ear was performed to show elastase-induced aneurysms in 34 rabbits. Twenty-eight (82%) aneurysms in which common origins of the bilateral common carotid artery (CCA) were found were well shown. All 6 other aneurysms not well shown had separate origins of the CCAs from the aortic arch (P , .001). This method can be used for angiographic follow-up when there is a common origin of the CCAs.. AB - Digital subtraction angiography through the central artery of the ear was performed to show elastase-induced aneurysms in 34 rabbits. Twenty-eight (82%) aneurysms in which common origins of the bilateral common carotid artery (CCA) were found were well ...
RESULTS. There were 27 patients (14 male, 13 female) with a mean age of 62 (range, 44-77) years. There were 10 patients with renal transplants; their native renal arteries were not evaluated. Each of the two experienced interventional and body magnetic resonance radiologists, who were blinded to the results, reviewed the digital subtraction angiography and magnetic resonance angiography images respectively. Digital subtraction angiography was used as the standard of reference. A total of 39 renal arteries from these 27 patients were evaluated. One of the arteries was previously stented and could not be assessed with magnetic resonance angiography due to severe artefacts. Of the remaining 38 renal arteries, two were graded as normal, seven as having mild stenosis (=50% but =75%). Magnetic resonance angiography and digital subtraction angiography were concordant in 89% of the arteries; magnetic resonance angiography overestimated the degree of stenosis in 8% and underestimated it in 3% of them. In ...
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A dynamic MR angiography technique, MR digital subtraction angiography (MR DSA), is proposed using fast acquisition, contrast enhancement, and complex subtraction. When a bolus of contrast is injected into a patient, data acquisition begins, dynamically acquiring a thick slab using a fast gradient e …
In many preliminary and feasibility studies, various contrast-enhanced MR angiorgaphic techniques have been implemented in the assessment of extracranial disease of the carotid artery. Different strategies are used to optimize image quality, including time-resolved and high-resolution techniques. Most of these reports, although based on small numbers of patients, suggest that contrast-enhanced MR angiography could become a diagnostic alternative as a fast, first screening method in patients suspected of having carotid artery disease, independently from the technique employed in the study.. DSA is still considered to be the criterion standard for imaging of arteriosclerotic supraaortic vessel disease. Harboring the risks of thromboembolic events, this technique can reduce the overall benefit of endarterectomy. Noninvasive techniques for imaging supraaortic vessels prevent this risk related to the diagnostic procedure and can be regarded as a safe alternative to DSA whenever possible.. We chose to ...
TY - JOUR. T1 - Advanced digital subtraction angiography and MR fusion imaging protocol applied to accurate placement of flow diverter device. AU - Faragò, Giuseppe. AU - Caldiera, Valentina. AU - Tempra, Giovanni. AU - Ciceri, Elisa. PY - 2016/2/1. Y1 - 2016/2/1. N2 - In recent years there has been a progressive increase in interventional neuroradiology procedures, partially due to improvements in devices, but also to the simultaneous development of technologies and radiological images. Cone beam CT (Dyna-CT; Siemens) is a method recently used to obtain pseudo CT images from digital subtraction angiography (DSA) with a flat panel detector. Using dedicated software, it is then possible to merge Dyna-CT images with images from a different source. We report here the usefulness of advanced DSA techniques (Syngo- Dyna CT, three-dimensional DSA iPilot) for the treatment of an intracranial aneurysm with a flow diverter device. Merging MR and Dyna-CT images at the end of the procedure proved to be a ...
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Typical digital subtraction angiography (DSA) acquisition rates are often inadequate for visualizing and analyzing fast-moving flow patterns. Therefore, an interpolation method that captures the angiographic flow pattern was developed. The temporal change of gray value in each pixel along a blood vessel records the flow movement at that location. Thus, temporal interpolation was performed on a pixel-by-pixel basis. To generate each interpolated image, a polynomial interpolation was applied to six sequential images. To validate the interpolation technique, a flow phantom was imaged with a high acquisition frame rate, and interpolation was done in a lower frame rate and compared to the acquired data. The interpolated images were also compared to results from linear interpolation and cubic spline interpolation. Clinical utility was illustrated on DSA images of cerebral vasculature with aneurysms. Image sequences of 60 frame/s were generated from DSA images acquired at 7.5 frame/s. The results show ...
BACKGROUND: Magnetic resonance (MR)-guided vascular interventions are of increasing interest, and, with the use of contrast-enhanced techniques, intraarterial contrast-enhanced MR angiography (ia-ce-MRA) competes with intraarterial digital subtraction angiography (ia-DSA) for the diagnostic evaluation of the infrainguinal vessel tree. PURPOSE: To assess the diagnostic value of ia-ce-MRA and high-resolution T1-weighted (hr-T1w) imaging compared to the gold-standard ia-DSA for residual stenosis and local dissections after femoropopliteal recanalization in patients with peripheral arterial occlusive disease (PAOD). MATERIAL AND METHODS: Eight patients with PAOD and short vessel occlusion of their femoropopliteal arteries underwent recanalization and balloon positioning under DSA. Patients were transferred to a short-bore MR scanner. Percutaneous transluminal angioplasty (PTA) was accomplished under MR fluoroscopy. Pre- and postinterventional ia-ce three-dimensional (3D) gradient-echo MRA with ...
The purpose was to evaluate the efficiacy of the time-of-flight MRA of the carotid artery with a 1.0 Tesla system in comparison to intraarterial digital subtraction angiography for the assessment of carotid artery disease. 101 patients with suspected stenosis of the carotid artery were examined with a 1.0 Tesla scanner in time-of-flight-technique and with the selective i.a. DSA in parallel. Morphological pathologies were registered for all arteries, stenosis of the internal carotid artery of both examinations were blindly graded by applying the NASCET criteria (mild, moderately, severely or occluded). Three different assessment methods were conducted for the MRA data. Kappa, weighted kappa, intraclass correlation were calculated for MRA results compared to DSA. Of the 84 common carotid bifurcation, 66 were classified as mild stenosis by DSA. In this category, MRA correctly identified 60 of these as mild stenosis. Among 60 common carotid artery bifurcation graded as moderate by DSA, 29 were ...
The applications of digital subtraction angiography (DSA) in neurologic diagnosis have been evolving as clinical experience with this technology accumulates. Initial enthusiasm with the intravenous contrast material injections has been tempered by often equivocal results. Intravenous DSA (IV-DSA) is still an accurate screening technique for extracranial carotid atherosclerosis, comparable to duplex ultrasound. Intracranial imaging is less satisfying with intravenous injections but reliable information is available in the assessment of the venous sinuses and parasellar internal arteries. The future of DSA lies with intraarterial contrast injections, as this technique substantially decreases the risks and costs of definitive cerebrovascular investigation. ...
Results-Cervical ICA PO occurred in 21/46 (46%) patients on CTA (17 proximal cervical; 4 midcervical). Fifteen (71%) of these patients also had PO on digital subtraction angiography. A flame-shaped PO mimicking a carotid dissection was seen in 7 (33%) patients on CTA and in 6 (29%) patients on digital subtraction angiography. Patients with and without CTA PO had similar age (64.8±17.1 versus 60.2±15.7 years; P=0.35), sex (male, 47% versus 52%; P=1.00), and intravenous tissue-type plasminogen activator use (38% versus 40%; P=1.00). The rates of modified Treatment In Cerebral Ischemia 2b-3 reperfusion were 71.4% in the PO versus 100% in the non-PO cohorts (P,0.01). The rates of parenchymal hematoma, 90-day modified Rankin Scale score 0-2, and 90-day mortality were 4.8% versus 8% (P=0.66), 40% versus 66.7% (P=0.12), and 25% versus 21% (P=0.77) in PO versus non-PO patients, respectively. Multivariate analysis indicated that PO patients had lower chances of modified Treatment In Cerebral Ischemia 3 ...
Ikeda H, Shibao K, Ohkita Y, Sugi K, Koga Y, Utsu F, Toshima H (1985) A quantitative evaluation of left ventricular function by digital subtraction angiography without using contrast medium: Time-activity curve and Fourier analysis (in Japanese). Kokyu to Junkan 34 (in press)Google Scholar ...
The digital subtraction angiography method useful for three dimensional (3D) imaging of a selected volume of a body comprises the following steps. Acquiring first and second 3D data sets representative of an image of substantially the same selected volume in the body, the first and second data sets being acquired at different times corresponding to a pre- and a post injection of a contrast medium, respectively. Determining common reference points for spatially corresponding subvolumes in the data sets. Comparing in a 3D spatial manner data in subvolumes of the second data set with data in corresponding subvolumes in the first data set in order to determine a new reference point in each of the subvolumes of the first data set which results in a best match of the spatial similarity of the data in the corresponding subvolumes of the second data set. Spatially interpolating new data for the subvolumes of said first data set using the new reference points determined above and the originally acquired
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Vessel segmentation is the base of 3d reconstruction of Digital Subtraction Angiograph (DSA) images. This paper proposes a framework of adaptive local thresholding based on a verification-based approach for vessel segmentation of DSA images. The original DSA image is firstly divided into overlapping subimages according to a priori knowledge of the diameter of vessels. We implement a hypothesis test to determine whether each subimage contains vessels and then choose an optimal threshold respectively for every subimage previously determined to contain vessels, with a secondary verification process to exclude the condition that the subregion only containing the background but misclassified as one containing vessels by the hypothesis test. Finally an overall binarization of the original image is achieved by combining the thresholded subimages. Experiments demonstrate superior performance over global thresholding and some adaptive local thresholding methods ...
70 year-old female with chronic obstructive pulmonary disease (COPD) presented with typical symptoms of an exacerbation of COPD. Management of COPD resolved her wheezing, but ongoing hypoxia and retrospective history of atypical chest pain prompted exclusion of a pulmonary embolus. A CT Pulmonary Angiogram (CTPA) with standard 64-slice CT revealed an extensive non-occlusive defect in a grossly dilated right pulmonary artery. Presence of circumferential cuff of soft tissue within sub-segmental pulmonary artery branch raised the possibility of pulmonary artery dissection (PAD). Exclusion of PAD was important as it precluded full anticoagulation. A dynamic CT-digital subtraction angiography (CT-DSA) with the 320-slice multidetector CT (Aquilion-one Vision, Toshiba) did not reveal any intimal flap or contrast extension into the pulmonary arterial wall, suggesting it is unlikely to be PAD. The patient was started on full anticoagulation and reported improvement of symptoms with reduction in pulmonary
BACKGROUND: Anterior inferior cerebellar artery (AICA) can present with a myriad of variations. However, the previous studies of AICA anatomy were based on small-scale cadaveric investigation. In this study, we performed an angiographic study of AICA in 500 Chinese with Han nationality based on digital subtraction angiography (DSA). METHODS: Patients admitted to our institution between 2015 and 2018 who had underwent DSA were potential candidates for this retrospective evaluation. The exclusion criteria were: a) patients with vascular diseases of the posterior circulation; b) ischemic diseases or moyamoya disease of the anterior circulation. RESULTS: Five hundred patients were identified. The patients ranged in age from 6 to 75 years. Two hundred thirty-seven (62.9%, 237 of 377) patients had bilateral AICAs at the same level, and 140 (37.1%, 140 of 377) had bilateral AICAs at different levels. The developing states of AICA were grade 0 in 31 (3.5%, 31 of 896), grade 1 in 373 (41.6%, 373 of 896), ...
As the right gastric artery is not the major contributor to the gastric bed, it is one that is often overlooked in literature relating to arterial variation. It is a highly variable artery; with studies showing it can arise from the hepatic artery proper (HAP), gastro duodenal artery (GDA) and the left, right, common or middle hepatic arteries [8,9,10]. Identification of the right gastric artery is critical, for interventional radiologists, since inadvertent chemotherapy delivery to this artery can result in significant gastric mucosal damage (necrosis, ulceration or perforation) [6,9]. Evidence shows that the correct identification and embolisation of the right gastric artery can reduce the incidence of these complications from 36% to 3% [11].. Selective internal radiotherapy (SIRT). SIRT initially gained approval in 2002 by the United States Food and Drug Administration (USFDA) for the treatment of hepatic metastases secondary to colorectal adenocarcinoma [12]. Access to the hepatic ...
The effect of demographic features on aortic arch anatomy and its role in the etiology of cerebrovascular disease Yılmaz İnanç,1 Yusuf İnanç,2 Halil Ay3 1Department of Neurology, Faculty of Medicine, Kahramanmaraş Sutcu Imam University, Kahramanmaraş, 2Department of Neurology, Faculty of Medicine, Gaziantep University, Gaziantep, 3Department of Neurology, Faculty of Medicine, Harran University, Harran, Turkey Purpose: The aim of this study was to retrospectively evaluate the distribution of aortic arches, the relationship with demographic characteristics, and the results of carotid and vertebral artery stenting procedures in patients diagnosed with cerebrovascular disease through the intra-arterial digital subtraction angiography (DSA) technique. Methods: A retrospective examination was performed on 288 patients diagnosed with cerebrovascular disease, who underwent DSA in the Department of Neurology of Gaziantep University Medical Faculty and Kahramanmaras¸ Sütç
In subtraction CT angiography (CTA), a non-contrast CT acquisition is subtracted from a contrast-enhanced CTA acquisition. Subtraction CTA can be applied in the detection, classification, and follow-up of intracranial aneurysms and is advantageous over conventional angiography because of its non-invasive nature, shorter examination time, and lower costs. Recently, an ultra-high-resolution CT scanner has been introduced in clinical practice offering an in-plane spatial resolution of up to 0.234 mm, approaching the resolution as seen during conventional invasive digital subtraction angiography (DSA). The twofold increase in spatial resolution as compared to a conventional CT scanner could improve the evaluation of small vascular structures and, coupled with dedicated post-processing techniques, further reduce metal artifacts. Technical considerations using a state-of-the-art high-resolution subtraction CTA protocol are discussed for application in the follow-up of surgical and endovascular treated
Abstract: : Purpose: Wide-angle Optomap images obtained from the Panoramic200 device captures a 200° field of the ocular fundus without dilation. In contrast, conventional digital imaging through a dilated pupil typically includes the disc and macula as the main image field. Peripheral fields must be specifically imaged in addition, if required. In this study, the accuracy of macular diagnoses made from macular images of the same eye obtained with both 50° and 200° imaging system types were compared. Methods: Thirty-five eyes were digitally imaged with both the Panoramic200 and the Topcon TRC50 50° fundus camera. Thirty-two eyes with macular disease and 3 normal eyes were studied. Images were randomly presented on a color-viewing monitor to the same retinal specialist (TRF) in a masked manner devoid of clinical information. Both color and red-free images were viewed. Diagnoses made from images acquired by each image system were compared to one another for accuracy, using the clinical ...
Purpose: To design a precise perfusion phantom mimicking capillaries of the brain vasculature which could be used to test various perfusion protocols and algorithms which generate perfusion maps. Methods: A perfusion phantom was designed in Solidworks and built using additive manufacturing. The phantom was an overall cylindrical shape of diameter and height 20mm and containing capillaries of 200μm or 300μm which were parallel and in contact making up the inside volume where flow was allowed. We created a flow loop using a peristaltic pump and contrast agent was injected manually. Digital Subtraction Angiographic images and low contrast images with cone beam CT were acquired after the contrast was injected. These images were analyzed by our own code in LabVIEW software and Time-Density Curve, MTT and TTP was calculated. Results: Perfused area was visible in the cone beam CT images; however, individual capillaries were not distinguishable. The Time-Density Curve acquired was accurate, sensitive ...
The last years have seen rapid progress in algorithms development for enhancing information in medical image data. Medical images play an important role in clinical diagnosis, therapy, research and teaching. To transfer the technical advances in this field into clinical practice, translational research efforts within a multidisciplinary team including basic scientists, clinical scientists and physicians are essential. In this talk, selected applications focusing on magnetic resonance imaging and 3D digital subtraction angiography (DSA) are presented that illustrate this concept ...
The purpose of the study was to evaluate the diagnostic performance of non- invasive imaging methods of detecting carotid artery stenosis in comparison to digital subtraction angiography (DSA) by undertaking a systematic review of the literature. The non-invasive methods reviewed include multislice computed tomography (MSCT) angiography, duplex ultrasound (US) and magnetic resonance (MR) angiography.A search of medical databases (PubMed, Medline, ScienceDirect, Proquest) of the English literature was performed and 22 studies with 68 comparisons were found to meet the selection criteria and included in our study. 5 studies were performed with MSCT angiography, 11 with duplex US and 13 with MR angiography. Both duplex US and MR angiography were studied in 7 out of 24 US and MR studies. The diagnostic value of each imaging modality was reviewed in terms of the sensitivity and specificity compared to DSA, which is regarded as the standard method.The mean sensitivity and specificity for MSCT ...
Methods MRI was performed for suspicion of CVS. For quantitative evaluation, the brain was partitioned into 19 arbitrary segments of comparable volume. Segments with PWI/DWI mismatch were defined as segment at risk (SR). In these cases, MRI was followed by angiography (digital subtraction angiography (DSA)) including endovascular treatment. 48±12 h after treatment, a second MRI was performed and the treatment was repeated if new or remaining SR were observed. Efficacy was classified as the percentage of reduced diameter of the proximal cerebral arteries on DSA following the treatment: mild (≥33%), moderate (34-66%) or severe (≥67%). ...
A digital subtraction angiography method useful for processing a mask and contrast series of two dimensional (2D) images acquired by rotational imaging of a selected volume of a body. The method reduces image artifacts caused by misregistration, and is unique in that for registration purposes it treats the acquired 2D images as a volume. The individual 2D images are stacked in a sequence so as to have the dimensions x, y and θ. A flexible volume registration is then performed to bring the mask and contrast volumes into a close match prior to subtraction.
Digital Subtraction Angiography (DSA) is an x-ray imaging modality for visualizing blood vessels. The DSA image is obtained by the logarithmic subtraction of an x-ray image with and without contrast agent in the blood vessel, called contrast image and mask image respectively. The aim of this work is to estimate the mask image from the given contrast image. Since the mask image will be estimated using the contrast image, the patient in a clinical setup will receive fewer x-ray doses for the same DSA protocol. ...
Keywords: Three-dimensional (3D) CT angiography, Temsirolimus Digital subtraction angiography, Coronary luminal stenosis Background Atherosclerotic plaque leads to progressively increasing luminal stenosis, which could result in fatal cardiac events. Coronary angiography is currently the gold standard technique for assessment of coronary lumen stenosis Temsirolimus or occlusion [1C4]. However, it is an invasive procedure. A catheter should be used to insert into the coronary arteries for injecting dye, which would induce discomfort for the patient. Furthermore, it has limitations of differentiating plaque components [5]. Therefore, it is of paramount importance to evaluate the lumen stenosis using non-invasive imaging techniques. During the past decades, CT angiography (CTA) has become a rapidly developing non-invasive imaging technique, which showed promising application in the identification, visualization and characterization of the coronary artery stenosis [6, 7]. Sun et al. [8, 9] have ...
An area of your body, usually the groin, is cleaned and numbed with a local numbing medicine (anesthetic). A thin, hollow tube called a catheter is placed through an artery. The catheter is carefully moved up through the main blood vessels in the belly area and chest into an artery in the neck. X-rays help the doctor guide the catheter to the correct position. Once the catheter is in place, the dye is sent through the catheter. X-ray images are taken to see how the dye moves through the artery and blood vessels of the brain. The dye helps highlight any blockages in blood flow.. Sometimes, a computer removes the bones and tissues on the images being viewed, so that only the blood vessels filled with the dye are seen. This is called digital subtraction angiography (DSA).. After the x-rays are taken, the catheter is withdrawn. Pressure is applied on the leg at the site of insertion for 10 to 15 minutes to stop the bleeding or a device is used to close the tiny hole. A tight bandage is then applied. ...
The respiratory liver motion simulator consists of a physical ovine liver, agar-gelatine block surrounding the liver, a medical air balloon which is connected to a lung ventilator, and two water balloons which are used to move the phantom back to its original position. The whole setup was MR compatible, including the ventilator which is used to provide simulation of respiratory motion. The movement generated by the simulator was analysed via an MR compatible ultrasound system, and this real-time motion information was used to guide a dynamic high intensity focused ultrasound system (Exablate 2100 system, 0.55MHz) to steer its focus to follow this motion (Figure 1). The liver model is perfused via an extracorporeal circuit driven by a heart lung bypass machine (HL30 Maquet, Germany). Continuous non pulsatile input into the portal vein of 220 ml/min saline, with output free draining into the venous system, forming a perfusion circuit. (Figure 2). Digital Subtraction Angiography contrast images of ...
Uzziniet vairāk par 3D-RA 3D Rotational Angiography imaging technology. Skatiet specifikācijas, lejupielādējiet atbalsta dokumentus un atklāt saistītus produktus.
A cart for weighing small animals with the cart having a torsional undercarriage mechanism that directs the weight of an animal in a weighing pen through a single tension support member wherein the elastic deformation of the single tension support member is measured with an electrical resistance strain gauge mounted on the tension support member and a conventional digital strain gauge read-out device.
Capture, manage, share and analyze terabytes of reality data of any size, from any system, into one single source of truth that provides 4D digital context.
Subtraction is a basic math concept that needs to be mastered in the early years. Make learning math fun with these subtraction activities on JumpStart - download now!
中文摘要:紅外線數位熱影像非常適合顯示受測物體曲面所發射紅外線輻射之二維溫度分佈,因此紅外線心臟熱影像又被稱為冠狀動脈熱像血管造影。在本研究中,提出了一種數位影像處理之演算法,以定位血栓阻塞或頸縮狹窄之位置。本演算法包含四個連續之處理過程;首先,針對紅外線數位熱影像之二維溫度灰階像素進行二值化處理,利用多閾值適性分割來區分心臟(背景)或冠狀動脈(前景)像素。接著第二處理過程將分割所得原始動脈像素,經過一連串之胡椒狀像素去除(pepper-like pixels removing)、外圍像素侵蝕(erosion)、與原區域相減(subtraction)、遞迴式鄰域探訪(recursive neighborhood visiting)、動脈輪廓點串鏈(point linked ...
Once children get to grips with concepts like addition, subtraction, multiplication and division, they have the foundation for more complex concepts.
Hundred Printable 100 Square Grid Subtraction Strategies , 460 X 341. Why not consider picture over? is of which remarkable???. if you feel therefore, Il t explain to you a number of picture once more under:. ...
Rapid diagnosis of thoracic aortic transection using intravenous digital subtraction angiography. Limited value of technetium 99m-labeled red cell scintigraphy in localization of lower gastrointestinal bleeding
PURPOSE: To prospectively compare the accuracy of 16-detector row computed tomographic (CT) angiography with conventional digital subtraction angiography (DSA) as the reference standard in the assessment of aortoiliac and lower extremity arteries in patients with peripheral arterial disease. MATERIALS AND METHODS: This study was approved by the institutional review board, and informed consent was obtained. A total of 39 consecutive patients (27 men [mean age, 66 years] and 12 women [mean age, 64 years]) with peripheral arterial disease underwent both conventional DSA and 16-detector row CT angiography. For data analysis, the arterial vascular system was divided into 35 segments. A total of 1365 arterial segments were analyzed for arterial stenosis by two independent blinded readers using a four-point grading system (grade 1, ,10% luminal narrowing; grade 2, 10%-49% luminal narrowing; grade 3, 50%-99% luminal narrowing; grade 4, occlusion). Interobserver agreements were calculated by using kappa ...
J Neurosurg 127:725-731, 2017. The study aimed to assess the diagnostic accuracy of 320-detector row nonsubtracted and subtracted volume CT angiography (VCTA) in detecting small cerebral aneurysms (, 3 mm) compared with 3D digital subtraction angiography (3D DSA).. METHODS Six hundred sixty-two patients underwent 320-detector row VCTA and 3D DSA for suspected cerebral aneurysms. Five neuroradiologists independently reviewed VCTA and 3D DSA images. The 3D DSA was considered the reference standard, and the sensitivity, specificity, and accuracy of nonsubtracted and subtracted VCTA in depicting small aneurysms were analyzed. A p value , 0.05 was considered a significant difference.. RESULTS According to 3D DSA images, 98 small cerebral aneurysms were identified in 90 of 662 patients. Nonsubtracted VCTA depicted 90 small aneurysms. Ten small aneurysms were missed, and 2 small aneurysms were misdiagnosed. The missed small aneurysms were located almost in the internal carotid artery, near bone tissue. ...
Conray is indicated for use in excretory urography, cerebral angiography, peripheral arteriography, venography, arthrography, direct cholangiography, endoscopic retrograde cholangiopancreatography, contrast enhancement of computed tomographic brain images, cranial computerized angiotomography, intravenous digital subtraction angiography and arterial digital subtraction angiography. Conray may also be used for enhancement of computed tomographic scans performed for detection and evaluation of lesions in the liver, pancreas, kidneys, abdominal aorta, mediastinum, abdominal cavity and retroperitoneal space ...
Atherosclerosis of the lower leg arteries is a common disease. Patients with this condition has symptoms of ischemia, for instance intermittent claudication (pain during exercise). Diagnosis of atherosclerosis in the legs is normally done with an interventional x-ray-based angiography (DSA- digital subtraction angiography). This is uncomfortable for the patient, and associated with risks of complications (bleeding, vascular damage, embolism).A novel approach to diagnosing atherosclerosis is the use of magnetic resonance angiography. A variant of this is the whole body magnetic resonance angiography(WB-MRA), that produce a picture of the arteries in almost the whole body (excluding the coronary arteries). WB-MRA has a number of advantages compared to DSA. It does not use ionizing radiation, is not invasive, uses a contrast medium with fewer side affects and finally gives a covers a great deal of the arteries in the body.. This study will compare WB-MRA with DSA in patients with symptoms of ...
2Akdeniz University, School of Medicine, Department of Radiology, Antalya, Turkey DOI : 10.5137/1019-5149.JTN.10299-14.3 AIM: To understand the late anatomical results of surgically treated intracranial aneurysms (IAs) and to investigate the incidence of recurrent, de novo aneurysms, the natural history of residual aneurysms, and the morphological changes in temporarily clipped vascular segments.. MATERIAL and METHODS: A total of 117 patients underwent screening with digital subtraction angiography (DSA) or computed tomographic angiography (CTA) in a range of 3 - 13 years. Late angiographies were evaluated in terms of recurrence, change in known residua, the presence of de novo aneurysms and the morphological changes in temporarily clipped vessels. We also analysed the cumulative data including previously published results.. RESULTS: In the long-term DSA, three residual aneurysms were observed to be enlarged while four remnants showed no morphological change. In one patient, spontaneous ...
TY - JOUR. T1 - Videodensitometric quantitation of stenosis. T2 - In vitro and in vivo validation. AU - Seibert, J Anthony. AU - Link, Daniel P. AU - Hines, H. H.. AU - Baltaxe, H. A.. PY - 1985. Y1 - 1985. N2 - Percentage of stenosis of a vascular lumen was quantitated using a digital subtraction angiography system with videodensitometric analysis. To validate the algorithm and methods, we used precisely drilled Lucite rods of three inner diameters and various reduced diameters to give known luminal reduction. Both in vitro and in vivo results of stenosis measurements resulted in an excellent correlation between actual and measured values (correlation coefficient , 0.9 for all trials). Consistent underestimation of stenosis of about 5% was attributed to the various image degradations inherent with the imaging procedure and equipment. Errors were greatest with mid range stenoses and less at the extremes of the lesion values. An insufficient signal-to-noise ratio was caused by low photon flux ...
In most cases, the disease can be detected during a normal checkup with a physician. Some of the tests a physician can use or order include history and physical exam, doppler ultrasound imaging, oculoplethysmography (OPG), computed tomography (CT), arteriography and digital subtraction angiography (DSA), and magnetic resonance angiography (MRA). Frequently, these procedures are carried out in steps. First, there is the doctors evaluation of signs and symptoms then an ultrasound. Arteriography, DSA or MRA are reserved for difficult diagnoses.. A doctor will ask about symptoms of a stroke such as numbness or muscle weakness, speech or vision difficulties, or lightheadedness. Using a stethoscope, a doctor may hear a rushing sound, called a bruit (pronounced "brew-ee"), in the carotid artery. Unfortunately, dangerous levels of disease sometimes fail to make a sound, and some blockages with a low risk can make a sound.. Doppler ultrasound imaging. This is a painless, noninvasive test in which sound ...
In patients presenting with a suspected acute stroke, clinicians attempt to confirm the presence of cerebral ischemia, identify the extent of the neurological deficit, and determine the etiology of the event. To detect a carotid source, patients usually undergo carotid duplex scan, CT angiography, conventional MRA, or digital subtraction angiography, all of which rely heavily on percent stenosis. Although these methods can detect luminal narrowing to a high degree of certainty, they cannot identify unstable plaque components. The current study and others have shown that stenosis does not fully determine the potential for embolization from the carotid artery. Traditionally, mild and moderate carotid artery stenoses have been overlooked as potential sources for thromboembolic stroke.. Although studies have found that complex carotid plaques (American Heart Association Type VI plaques) are associated with increased risk of subsequent events,7 the final common pathway has not been evaluated ...
BACKGROUND: Magnetic resonance angiogram (MRA) of the brain is a widely employed non-invasive test to diagnose aneurysms. However, its overall accuracy is less than digital subtraction angiography and is prone to give false-positive or false-negative results. False-negative results can be seen with hemorrhage, lipoma, dermoid, posterior lobe of the pituitary gland, and the flow artifacts. PURPOSE: To describe the findings associated with false aneurysms in the anterior communicating artery on the time of flight MRA and review the physical principles behind this artifact. MATERIAL AND METHODS: This short series comprises of four patients whose MRA showed suspicious aneurysms in the region of the anterior communicating artery (ACOM) on time of flight MRA. RESULTS: Two patients underwent catheter angiogram and the other two patients had computed tomography angiogram. None of these cases proved to have aneurysms and normal anterior communicating arteries were seen in all the patients. The findings on the MR
OBJECTIVE: To evaluate the value of magnetic resonance imaging (MRI) and three dimensional (3D) contrast magnetic resonance angiography (MRA) in the diagnosis of complications of simultaneous pancreas-kidney transplantation (SPKT), as confirmed by biopsy and digital subtraction angiography (DSA). METHODS: Five MR examinations of five patients were performed within 28 days to 2 years after surgery on GE 1.5T MR system. Imaging techniques included axial and sagittal chemical fat-suppressed T1-weighted image (T1WI) and T2-weighted image (T2WI), additional contrast axial or saggital chemical fat-suppressed T1WI were obtained after 3D contrast MRA for calculating the mean percentage of the parenchymal enhancement (MPPE) of the pancreas and kidney ...
DF = Digital Fluoroscopy (retired). *DG = Diaphanography. *DM = Digital Microscopy. *DS = Digital Subtraction Angiography ... DICOM, abreviação de Digital Imaging and Communications in Medicine (ou comunicação de imagens digitais em medicina), é um ...
This is based on MRI scan, magnetic resonance angiography and CT scan. A cerebral digital subtraction angiography (DSA) ... High resolution digital subtraction angiography may help in classifying CCF into dural and direct type and thus formulate a ...
Angiography Computed Tomography Angiography Contrast Medium Intravenous digital subtraction angiography Radiography " ... "Micro-angiography for tumor vessel imaging" (PDF). Retrieved 2009-06-10. Bollinger A, Amann-Vesti BR (June 2007). "Fluorescence ... While most other types of angiography cannot produce images of vessels smaller than 200 µm in diameter, microangiography does ... Microangiography (/ˌmaɪkroʊˌændʒiˈoʊɡrəfi/ MY-cro-AN-jee-OH-grə-fee) is a recently developed type of angiography that consists ...
The gold standard is cerebral angiography (with or without digital subtraction angiography). This involves puncture of a large ... MR angiography). They use smaller amounts of contrast and are not invasive. CT angiography and MR angiography are more or less ... When MR angiography is used, the best results are achieved in the T1 setting using a protocol known as "fat suppression". ... Angiography also does not directly demonstrate the blood in the vessel wall, as opposed to more modern modalities. The only ...
The DR 960 was introduced in 1982 as a digital subtraction angiography device. Rather than injecting contrast material into an ... A digital image was acquired without contrast and one with, and the images subtracted from each other leaving the arterial ... essentially a digital x-ray that was produced by moving the body through the gantry with the x-ray tube stationary. This ...
... validated by digital subtraction angiography". AJNR. 27 (7): 1565-72. PMID 16908582. Greathouse, David G.; Halle, John S.; ... "MR Angiography and CT Angiography of the Artery of Adamkiewicz: Noninvasive Preoperative Assessment of Thoracoabdominal Aortic ... Nijenhuis RJ, Mull M, Wilmink JT, Thron AK, Backes WH (2006). "MR angiography of the great anterior radiculomedullary artery ( ... Its location can be identified with computed tomographic angiography. It is named for Albert Wojciech Adamkiewicz. Milen, Mark ...
Comparison of computed tomography angiography with digital subtraction angiography in the assessment of clipped intracranial ... CT Angiography and MR Angiography for Detection-Prospective Blinded Comparison in a Large Patient Cohort". Radiology. 219 (3): ... Once suspected, intracranial aneurysms can be diagnosed radiologically using magnetic resonance or CT angiography. But these ...
... by Digital Subtraction Imaging". Journal of Zoo and Wildlife Medicine. 30 (2): 235-241. PMID 10484138. "Magnetic Resonance ... Angiography using X-rays or magnetic resonance angiography are methods to visualize blood vessels. The term "anatomy" is ... "Angiography". National Health Service. Retrieved 29 April 2014. Dorit, R. L.; Walker, W. F.; Barnes, R. D. (1991). Zoology. ... Gribble N, Reynolds K (1993). "Use of Angiography to Outline the Cardiovascular Anatomy of the Sand Crab Portunus pelagicus ...
Today, the gold standard imaging remains invasive pulmonary angiography (PAG) using native angiograms or a digital subtraction ... of ventilation/perfusion scanning and multidetector computed tomography pulmonary angiography with pulmonary angiography". ... Both V/Q scanning and modern multidetector CT angiography (CTPA) may be accurate methods for the detection of CTEPH, with ... scan and specific diagnostic signs for CTEPH seen by multidetector computed tomography angiography (MDCT), magnetic resonance ...
... by Digital Subtraction Imaging". Journal of Zoo and Wildlife Medicine. 30 (2): 235-241. PMID 10484138.. ... "Magnetic Resonance Angiography (MRA)". Johns Hopkins Medicine.. *^ "Angiography". National Health Service. Retrieved 29 April ... Angiography using X-rays or magnetic resonance angiography are methods to visualize blood vessels.[8][9][10][11] ... Gribble N, Reynolds K (1993). "Use of Angiography to Outline the Cardiovascular Anatomy of the Sand Crab Portunus pelagicus ...
... digital subtraction angiography, and new technologies. An additional focus is that of contrast media research, primarily for ...
The position of the correct artery or vein supplying the pathology in question is located by digital subtraction angiography ( ...
Techniques such as conventional digital subtraction angiography (DSA) and magnetic resonance imaging (MRI) are used to find and ... Cerebral angiography and magnetic resonance imaging, family medical history, symptoms, a complete physical examination, and ...
The services provided at hospitals are X-Ray and Ultrasound, MRI, CT scan, Digital Subtraction Angiography, Colour Doppler ...
Digital subtraction angiography (DSA) is a two-dimensional imaging technique for the visualization of blood vessels in the ... ISBN 978-953-51-0148-2. Katzen, B. T. (January 1995). "Current Status of Digital Angiography in Vascular Imaging". Radiologic ... Rotational angiography is a technique to acquire CT-like 3D images intraoperatively with a fixed C-Arm. To do that, the C-Arm ... Rotational angiography visualizes the bronchial tree in 3D during the procedure. The air thereby serves as a 'natural' contrast ...
... comparison with intraarterial digital subtraction angiography". World J Surg. 27 (3): 278-83. doi:10.1007/s00268-002-6701-1. ... with contrast-enhanced three-dimensional fast imaging with steady-state precession magnetic resonance angiography: ...
In 1989 the first Magnetic Resonance Imaging (MRI) and Digital subtraction angiography (DSA) were installed, setting precedent ...
Charles Mistretta in 1979 invented digital subtraction angiography (DSA), the technique currently in use. It consists of ... Diagnostic angiography The first experience with cerebral angiography was developed by Portuguese doctor Egas Moniz at the ... He performed the first brain angiography in Lisbon in 1927 by injecting iodinated contrast medium into a carotid and using the ... In 1964, the Norwegian radiologist Per Amudsen was the first to perform a complete brain angiography with a transfemoral ...
... advocacy group for the use of a base-12 numeral system Digital subtraction angiography, a fluoroscopy technique Doncaster ... Singapore Digital Signature Algorithm Directory System Agent, an IT standard, part of X.500 Defence Safety Authority, UK ...
MRI scans of the brain and orbit with and without contrast, magnetic resonance angiography or digital subtraction angiography ...
... to diagnose myocardial infarction Arteriography of the affected extremity or organ Digital subtraction angiography is useful in ...
DSA (digital subtraction angiography) of carotid artery to see the extension of tumors and feeding vessels Antro-choanal polyp ...
Digital Subtraction Angiography (DSA), Dual Source CT Scan 1.5 T MRI, High Definition PET with 4D CT Scan, Image Intensifier TV ...
... angiography, digital subtraction MeSH E01.370.350.600.350.700.690 --- radiography, dental, digital MeSH E01.370.350.600.350.700 ... angiography, digital subtraction MeSH E01.370.350.700.700.690 --- radiography, dental, digital MeSH E01.370.350.700.700.700 ... subtraction technique MeSH E01.370.350.760.060 --- angiography, digital subtraction MeSH E01.370.350.760.700 --- radiography, ... angiography MeSH E01.370.370.050.050 --- angiocardiography MeSH E01.370.370.050.060 --- angiography, digital subtraction MeSH ...
... digital mammography, 4D color doppler, 256 slice CT scan, Biplane DSA (digital subtraction angiography). Some free laboratory ... advanced radiology setup including digital X-ray, ...
... comparison with intraarterial digital subtraction angiography". World Journal of Surgery. 27 (3): 278-83. doi:10.1007/s00268- ... with contrast-enhanced three-dimensional fast imaging with steady-state precession magnetic resonance angiography: ...
Comparisons between digital subtraction angiography and conventional angiography have frequently been made in the radiologic ... Intraarterial digital subtraction angiography for definitive diagnosis of intracranial aneurysms.. H Touho, J Karasawa, T ... Intraarterial digital subtraction angiography for definitive diagnosis of intracranial aneurysms.. H Touho, J Karasawa, T ... Intraarterial digital subtraction angiography for definitive diagnosis of intracranial aneurysms.. H Touho, J Karasawa, T ...
... reviewed the digital subtraction angiography and magnetic resonance angiography images respectively. Digital subtraction ... Key words: Angiography, digital subtraction; Gadolinium; Magnetic resonance angiography; Renal artery obstruction; Sensitivity ... Records of patients who underwent magnetic resonance angiography as well as digital subtraction angiography for assessment of ... Gadolinium-enhanced magnetic resonance angiography in renal artery stenosis: comparison with digital subtraction angiography ...
Intra-arterial digital subtraction angiography through the ear artery for experimental aneurysm imaging. / Ding, Y. H.; Dai, D ... N2 - Digital subtraction angiography through the central artery of the ear was performed to show elastase-induced aneurysms in ... AB - Digital subtraction angiography through the central artery of the ear was performed to show elastase-induced aneurysms in ... Digital subtraction angiography through the central artery of the ear was performed to show elastase-induced aneurysms in 34 ...
Rapid diagnosis of thoracic aortic transection using intravenous digital subtraction angiography. Limited value of technetium ... Rapid diagnosis of thoracic aortic transection using intravenous digital subtraction angiography. Article Abstract:. One ... It is possible that another angiographic approach, intravenous digital subtraction angiography (IVDSA), could enhance the speed ... One cause of the high death rate is the length of time required for conventional biplane angiography, a method of viewing the ...
"Introduction to Digital Subtraction Angiography". The cost effectiveness of digital subtraction angiography in the diagnosis of ... Hence the term "digital subtraction angiography". Subtraction angiography was first described in 1935 and in English sources in ... Intravenous digital subtraction angiography (IV-DSA) is a form of angiography which was first developed in the late 1970s. IV- ... DAlotto C, Pelz DM, Rankin RN (September 1985). "A comparison of angiography, intravenous digital subtraction angiography and ...
... generalized framework for histogram-based similarity measures is presented and applied to the image-enhancement task in digital ... subtraction angiography (DSA). The class of differentiable, strictly... ... L. V. Tran and J. Sklansky, Flexible mask subtraction for digital angiography, IEEE Trans. on Medical Imaging 11 (1992) 407 and ... Buzug T.M., Weese J., Lorenz C., Beil W. (1997) Histogram-based image registration for digital subtraction angiography. In: Del ...
Digital subtraction angiography, whether based on traditional X-ray or MR, suers from patient motion artifacts. Until now, the ... Motion compensated digital subtraction angiography. Hemmendorff, M. Linköping University, Department of Electrical Engineering ... Motion Compensation, Motion Estimation, Digital Subtraction Angiography, Aperture Problem, Pixelshift, Automatic, Quadrature ... time can be significantly reduced in ordinary peripheral angiographies and that the number of retakes due to large or local ...
Digital subtraction angiography definition, a computerized x-ray technique in which arteries are visualized following injection ... digital subtraction angiography. in Medicine. digital subtraction angiography. .css-1khtv86{font-size:20px;color:#c0b5b5;}.css- ... digital subtraction angiography. .css-7w6khc{padding-top:20px;}. .css-1oucjfz{list-style-type:none;line-height:22px;}. *digital ... digital subtraction angiography. .css-1g5b64m{padding:16px 0;}. .css-1fvpz4m{margin-right:32px;outline:none;border:none;padding ...
Digital Subtraction Pulmonary Angiography. Digital subtraction pulmonary angiography (DSPA) is the criterion standard or ... digital subtraction pulmonary angiography (DSPA), pulmonary computed tomography angiography (PCTA), and pulmonary magnetic ... Because digital subtraction pulmonary angiography (DSPA) is perceived to be invasive and requires the use of iodinated contrast ... Pulmonary angiography. Digital subtraction pulmonary angiogram shows splaying of the arterial branches of the right upper lobe ...
Compare risks and benefits of common medications used for Digital Subtraction Angiography. Find the most popular drugs, view ... What is Digital Subtraction Angiography: Digital Subtraction Angiography (DSA) is a type of fluoroscopy technique used in ... Medications to treat Digital Subtraction Angiography. The following list of medications are in some way related to, or used in ... Looking for answers? Ask a question or go join the digital subtraction angiography support group to connect with others who ...
... (DSA) is a technique used in interventional radiology to clearly visualize blood vessels ... Digital Subtraction Angiography (DSA) is a technique used in interventional radiology to clearly visualize blood vessels in a ... It uses material from the Wikipedia article "Digital_subtraction_angiography". A list of authors is available in Wikipedia. ... In traditional angiography images are acquired by exposing an area of interst with time-controlled x-rays while injecting ...
Associations of Angiography, Digital Subtraction with chemical compounds. *Digital subtraction angiography with a gadolinium ... High impact information on Angiography, Digital Subtraction. *Transvenous digital subtraction angiography was used before ... Anatomical context of Angiography, Digital Subtraction. *Associations of Angiography, Digital Subtraction with chemical ... routine and digital subtraction angiography, and phlebography [35].. *A combination of digital subtraction angiography and a ...
Digital subtraction angiography: current clinical applications.. D M Pelz, A J Fox, F Vinuela ... The applications of digital subtraction angiography (DSA) in neurologic diagnosis have been evolving as clinical experience ...
... automatic examination pre-sets support a smooth and efficient workflow in angiography examinations. ... With Philips Digital Subtraction Angiography (DSA) automatic examination pre-sets support a smooth and efficient workflow in ... angiography examinations. To extend flexibility and safety during DSA examinations the CombiDiagnost R90 table is enhanced with ...
For postprocessing of digital subtraction angiography (DSA) series, a newly implemented algorithm of parametric color coding ... Parametric color coding of digital subtraction angiography in the evaluation of carotid cavernous fistulas.. Gölitz P1, ...
Assessment of regional wall motion abnormality without contrast medium by digital subtraction angiography using Fourier ... A quantitative evaluation of left ventricular function by digital subtraction angiography without using contrast medium: Time- ...
Digital subtraction angiography with clinical correlation. The Journal of the American Osteopathic Association, February 1985, ... Osborn R. Digital subtraction angiography with clinical correlation. J Am Osteopath Assoc 1985;85(2):77. doi: 10.7556/jaoa. ... Digital subtraction angiography with clinical correlation You will receive an email whenever this article is corrected, updated ...
... means the sales value of Digital Subtraction Angiography(DSA? This report studies sales (consumption) of Digital Subtraction ... Angiography(DSA)in Europe market, especially in Germany, UK, France, Russia, Italy, Benelux and Spain, focuses on top players ... means the sales volume of Digital Subtraction Angiography(DSA? Revenue, ... 5.3 UK Digital Subtraction Angiography(DSA)Sales and Market Share by Type. 5.4 UK Digital Subtraction Angiography(DSA)Sales and ...
3D digital subtraction angiography image processing apparatus US20050046644A1 (en) * 2003-08-28. 2005-03-03. Satoru Ohishi. 3D ... Rotational digital subtraction angiography phantom Download PDF Info. Publication number. US5712895A. US5712895A US08783503 ... Rotational digital subtraction angiography phantom Applications Claiming Priority (1). Application Number. Priority Date. ... US08783503 1997-01-14 1997-01-14 Rotational digital subtraction angiography phantom Expired - Fee Related US5712895A (en) ...
Color-Coded Digital Subtraction Angiography: The End of a Monochromatic Era? Message Subject (Your Name) has sent you a message ... Intra-arterial digital subtraction angiography. In: Benndorf G ed. Dural Cavernous Sinus Fistulas: Diagnosis and Endovascular ... Parametric imaging using digital subtraction angiography. Br J Radiol 1986;59:7-11. ... Color-Coded Digital Subtraction Angiography: The End of a Monochromatic Era?. G. Benndorf ...
Fourteen patients suspected of having Moya Moya disease underwent intravenous digital subtraction angiography (DSA), and the ... Moya moya disease: use of digital subtraction angiography in its diagnosis Radiology. 1985 Oct;157(1):107-11. doi: 10.1148/ ... Fourteen patients suspected of having Moya Moya disease underwent intravenous digital subtraction angiography (DSA), and the ...
A method and system for extracting coronary vessels fluoroscopic image sequences using coronary digital subtraction angiography ... Digital subtraction angiography JP2018501008A (en) * 2015-01-05. 2018-01-18. コーニンクレッカ フィリップス エヌ ヴェKoninklijke Philips N.V.. ... Digital subtraction angiography for 3D diagnostic imaging US6154518A (en) * 1996-10-28. 2000-11-28. General Electric Company. ... Digital subtraction angiography for 3D diagnostic imaging US6154518A (en) * 1996-10-28. 2000-11-28. General Electric Company. ...
A framework for spacial-variant thresholding of digital subtraction angiography images Author(s): Nong Sang; Weixue Peng; Heng ... Vessel segmentation is the base of 3d reconstruction of Digital Subtraction Angiograph (DSA) images. This paper proposes a ...
IA-DSA is defined as imaging and intra-arterial digital subtraction angiography rarely. ... IA-DSA stands for imaging and intra-arterial digital subtraction angiography. ... How is imaging and intra-arterial digital subtraction angiography abbreviated? ... arterial-digital-subtraction-angiography-(IA_DSA).html,IA-DSA,/a,. Citations. *MLA style: "IA-DSA." Acronym Attic. 2018. ...
intra-arterial digital subtraction angiography 的翻译结果:动脉数字减影血管造影;动脉法数字减 ... intra-arterial digital subtraction angiography. Non-selective intra-arterial digital subtraction angiography for the assessment ... MR angiography versus intra-arterial digital subtraction angiography of the lower extremities: activity-based cost analysis ... We compared magnetic resonance angiography(MRA)and intra-arterial digital subtraction angiography(IA-DSA)in 20
  • It will be appreciated, however, that the invention will also find application in other rotational angiography systems, and the like. (google.com)
  • Ikeda H, Shibao K, Ohkita Y, Sugi K, Koga Y, Utsu F, Toshima H (1985) A quantitative evaluation of left ventricular function by digital subtraction angiography without using contrast medium: Time-activity curve and Fourier analysis (in Japanese). (springer.com)
  • Cerebral angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the brain. (medlineplus.gov)
  • Urgent MRI of the brain with angiography was requested (b), not only to detect small areas of infarction or hemorrhage that likely were overlooked on imaging with nonenhanced CT, but also to evaluate for large- or medium-vessel changes. (cmaj.ca)
  • After the introduction and rapid progress of cross-sectional imaging methods, such as CT angiography, MR angiography, and Doppler sonography in the late 80s and early 90s, many radiologists believed that these noninvasive methods would soon completely replace intra-arterial angiography. (ajnr.org)