Contrast Media: Substances used to allow enhanced visualization of tissues.Triiodobenzoic Acids: Triiodo-substituted derivatives of BENZOIC ACID.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.Iopamidol: A non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiological procedures.Ioxaglic Acid: A low-osmolar, ionic contrast medium used in various radiographic procedures.Diatrizoate: A commonly used x-ray contrast medium. As DIATRIZOATE MEGLUMINE and as Diatrizoate sodium, it is used for gastrointestinal studies, angiography, and urography.Diatrizoate Meglumine: A versatile contrast medium used for DIAGNOSTIC X-RAY RADIOLOGY.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Iodine Compounds: Inorganic compounds that contain iodine as an integral part of the molecule.Iothalamate Meglumine: A radiopaque medium used for urography, angiography, venography, and myelography. It is highly viscous and binds to plasma proteins.Extravasation of Diagnostic and Therapeutic Materials: The escape of diagnostic or therapeutic material from the vessel into which it is introduced into the surrounding tissue or body cavity.Urography: Radiography of any part of the urinary tract.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.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)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.Hysterosalpingography: Radiography of the uterus and fallopian tubes after the injection of a contrast medium.Iodine: A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126.90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically.Iodized Oil: A preparation of oil that contains covalently bound IODINE. It is commonly used as a RADIOCONTRAST AGENT and as a suspension medium for CHEMOTHERAPEUTIC AGENTS.Angiography: Radiography of blood vessels after injection of a contrast medium.Osmolar Concentration: The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.Angiocardiography: Radiography of the heart and great vessels after injection of a contrast medium.Iodopyridones: Iodinated pyridine derivatives that are often used as contrast media.Iothalamic Acid: A contrast medium in diagnostic radiology with properties similar to those of diatrizoic acid. It is used primarily as its sodium and meglumine (IOTHALAMATE MEGLUMINE) salts.Fallopian Tube Patency Tests: Methods for assessing the patency of the fallopian tubes.Drug Hypersensitivity: Immunologically mediated adverse reactions to medicinal substances used legally or illegally.Kidney Diseases: Pathological processes of the KIDNEY or its component tissues.Acute Kidney Injury: Abrupt reduction in kidney function. Acute kidney injury encompasses the entire spectrum of the syndrome including acute kidney failure; ACUTE KIDNEY TUBULAR NECROSIS; and other less severe conditions.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.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.Iodobenzoates: Benzoic acid esters or salts substituted with one or more iodine atoms.Injections, Intra-Arterial: Delivery of drugs into an artery.Coronary Angiography: Radiography of the vascular system of the heart muscle after injection of a contrast medium.CreatinineThorium Dioxide: Thorium oxide (ThO2). A radiographic contrast agent that was used in the early 1930s through about 1954. High rates of mortality have been linked to its use and it has been shown to cause liver cancer.Injections, Intravenous: Injections made into a vein for therapeutic or experimental purposes.Nephrogenic Fibrosing Dermopathy: A chronic, acquired, idiopathic, progressive eruption of the skin that occurs in the context of RENAL FAILURE. It is sometimes accompanied by systemic fibrosis. The pathogenesis seems to be multifactorial, with postulated involvement of circulating fibrocytes. There is a strong association between this disorder and the use of gadolinium-based contrast agents.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.Mass Media: Instruments or technological means of communication that reach large numbers of people with a common message: press, radio, television, etc.Iophendylate: An inert iodine-containing agent which is opaque to X-RAYS. It is used mainly for BRAIN and SPINAL CORD visualization.Otitis Media: Inflammation of the MIDDLE EAR including the AUDITORY OSSICLES and the EUSTACHIAN TUBE.Cerebral Angiography: Radiography of the vascular system of the brain after injection of a contrast medium.Sodium Bicarbonate: A white, crystalline powder that is commonly used as a pH buffering agent, an electrolyte replenisher, systemic alkalizer and in topical cleansing solutions.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)Tungsten Compounds: Inorganic compounds that contain tungsten as an integral part of the molecule.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.Subacute Care: Medical and skilled nursing services provided to patients who are not in an acute phase of an illness but who require a level of care higher than that provided in a long-term care setting. (JCAHO, Lexikon, 1994)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.Endolymphatic Hydrops: An accumulation of ENDOLYMPH in the inner ear (LABYRINTH) leading to buildup of pressure and distortion of intralabyrinthine structures, such as COCHLEA and SEMICIRCULAR CANALS. It is characterized by SENSORINEURAL HEARING LOSS; TINNITUS; and sometimes VERTIGO.Acetylcysteine: The N-acetyl derivative of CYSTEINE. It is used as a mucolytic agent to reduce the viscosity of mucous secretions. It has also been shown to have antiviral effects in patients with HIV due to inhibition of viral stimulation by reactive oxygen intermediates.Culture Media, Conditioned: Culture media containing biologically active components obtained from previously cultured cells or tissues that have released into the media substances affecting certain cell functions (e.g., growth, lysis).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)Myelography: X-ray visualization of the spinal cord following injection of contrast medium into the spinal arachnoid space.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.Cicatrix: The fibrous tissue that replaces normal tissue during the process of WOUND HEALING.Renal Insufficiency: Conditions in which the KIDNEYS perform below the normal level in the ability to remove wastes, concentrate URINE, and maintain ELECTROLYTE BALANCE; BLOOD PRESSURE; and CALCIUM metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of PROTEINURIA) and reduction in GLOMERULAR FILTRATION RATE.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Cholecystography: Radiography of the gallbladder after ingestion of a contrast medium.Diverticulosis, Colonic: A pathological condition characterized by the presence of a number of COLONIC DIVERTICULA in the COLON. Its pathogenesis is multifactorial, including colon aging, motor dysfunction, increases in intraluminal pressure, and lack of dietary fibers.Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.Fluoroscopy: Production of an image when x-rays strike a fluorescent screen.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.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.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.Cholangiography: An imaging test of the BILIARY TRACT in which a contrast dye (RADIOPAQUE MEDIA) is injected into the BILE DUCT and x-ray pictures are taken.Anaphylaxis: An acute hypersensitivity reaction due to exposure to a previously encountered ANTIGEN. The reaction may include rapidly progressing URTICARIA, respiratory distress, vascular collapse, systemic SHOCK, and death.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Epidural Space: Space between the dura mater and the walls of the vertebral canal.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.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.Maleic Anhydrides: Used in copolymerization reactions, in the Diels-Alder(diene)synthesis, in the preparation of resins, pharmaceuticals and agricultural chemicals. It is a powerful irritant and causes burns.Lymphography: Radiographic study of the lymphatic system following injection of dye or contrast medium.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.Fluid Therapy: Therapy whose basic objective is to restore the volume and composition of the body fluids to normal with respect to WATER-ELECTROLYTE BALANCE. Fluids may be administered intravenously, orally, by intermittent gavage, or by HYPODERMOCLYSIS.Intervertebral Disc Displacement: An INTERVERTEBRAL DISC in which the nucleus pulposus has protruded through surrounding fibrocartilage. This occurs most frequently in the lower lumbar region.Angioplasty, Balloon, Coronary: Dilation of an occluded coronary artery (or arteries) by means of a balloon catheter to restore myocardial blood supply.Economics, Hospital: Economic aspects related to the management and operation of a hospital.Hemangioma, Cavernous: A vascular anomaly that is a collection of tortuous BLOOD VESSELS and connective tissue. This tumor-like mass with the large vascular space is filled with blood and usually appears as a strawberry-like lesion in the subcutaneous areas of the face, extremities, or other regions of the body including the central nervous system.Cineangiography: Motion pictures of the passage of contrast medium through blood vessels.Microbubbles: Small encapsulated gas bubbles (diameters of micrometers) that can be used as CONTRAST MEDIA, and in other diagnostic and therapeutic applications. Upon exposure to sufficiently intense ultrasound, microbubbles will cavitate, rupture, disappear, release gas content. Such characteristics of the microbubbles can be used to enhance diagnostic tests, dissolve blood clots, and deliver drugs or genes for therapy.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.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.Heterocyclic Compounds: Ring compounds having atoms other than carbon in their nuclei. (Grant & Hackh's Chemical Dictionary, 5th ed)Fallopian Tubes: A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.Arachnoiditis: Acute or chronic inflammation of the arachnoid membrane of the meninges most often involving the spinal cord or base of the brain. This term generally refers to a persistent inflammatory process characterized by thickening of the ARACHNOID membrane and dural adhesions. Associated conditions include prior surgery, infections, trauma, SUBARACHNOID HEMORRHAGE, and chemical irritation. Clinical features vary with the site of inflammation, but include cranial neuropathies, radiculopathies, and myelopathies. (From Joynt, Clinical Neurology, 1997, Ch48, p25)Meniere Disease: A disease of the inner ear (LABYRINTH) that is characterized by fluctuating SENSORINEURAL HEARING LOSS; TINNITUS; episodic VERTIGO; and aural fullness. It is the most common form of endolymphatic hydrops.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.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.Sulfur Hexafluoride: Sulfur hexafluoride. An inert gas used mainly as a test gas in respiratory physiology. Other uses include its injection in vitreoretinal surgery to restore the vitreous chamber and as a tracer in monitoring the dispersion and deposition of air pollutants.Meglumine: 1-Deoxy-1-(methylamino)-D-glucitol. A derivative of sorbitol in which the hydroxyl group in position 1 is replaced by a methylamino group. Often used in conjunction with iodinated organic compounds as contrast medium.Cerebral Ventriculography: Radiography of the ventricular system of the brain after injection of air or other contrast medium directly into the cerebral ventricles. It is used also for x-ray computed tomography of the cerebral ventricles.Radiographic Image Interpretation, Computer-Assisted: Computer systems or networks designed to provide radiographic interpretive information.Blood Volume Determination: Method for determining the circulating blood volume by introducing a known quantity of foreign substance into the blood and determining its concentration some minutes later when thorough mixing has occurred. From these two values the blood volume can be calculated by dividing the quantity of injected material by its concentration in the blood at the time of uniform mixing. Generally expressed as cubic centimeters or liters per kilogram of body weight.Coronary Thrombosis: Coagulation of blood in any of the CORONARY VESSELS. The presence of a blood clot (THROMBUS) often leads to MYOCARDIAL INFARCTION.Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.Phlebography: Radiographic visualization or recording of a vein after the injection of contrast medium.Chylothorax: The presence of chyle in the thoracic cavity. (Dorland, 27th ed)Glomerular Filtration Rate: The volume of water filtered out of plasma through glomerular capillary walls into Bowman's capsules per unit of time. It is considered to be equivalent to INULIN clearance.Sodium Chloride: A ubiquitous sodium salt that is commonly used to season food.Radiation 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).Ions: An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.Injections: Introduction of substances into the body using a needle and syringe.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)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.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)Scintillation Counting: Detection and counting of scintillations produced in a fluorescent material by ionizing radiation.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Pentetic Acid: An iron chelating agent with properties like EDETIC ACID. DTPA has also been used as a chelator for other metals, such as plutonium.Social Media: Platforms that provide the ability and tools to create and publish information accessed via the INTERNET. Generally these platforms have three characteristics with content user generated, high degree of interaction between creator and viewer, and easily integrated with other sites.Tissue Adhesions: Pathological processes consisting of the union of the opposing surfaces of a wound.Lipoma: A benign tumor composed of fat cells (ADIPOCYTES). It can be surrounded by a thin layer of connective tissue (encapsulated), or diffuse without the capsule.Renal Artery: A branch of the abdominal aorta which supplies the kidneys, adrenal glands and ureters.Fenoldopam: A dopamine D1 receptor agonist that is used as an antihypertensive agent. It lowers blood pressure through arteriolar vasodilation.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.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Evaluation Studies as Topic: Studies determining the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies. For drugs and devices, CLINICAL TRIALS AS TOPIC; DRUG EVALUATION; and DRUG EVALUATION, PRECLINICAL are available.Hemodiafiltration: The combination of hemodialysis and hemofiltration either simultaneously or sequentially. Convective transport (hemofiltration) may be better for removal of larger molecular weight substances and diffusive transport (hemodialysis) for smaller molecular weight solutes.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.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.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.Culture Media, Serum-Free: CULTURE MEDIA free of serum proteins but including the minimal essential substances required for cell growth. This type of medium avoids the presence of extraneous substances that may affect cell proliferation or unwanted activation of cells.Arthrography: Roentgenography of a joint, usually after injection of either positive or negative contrast medium.Agar: A complex sulfated polymer of galactose units, extracted from Gelidium cartilagineum, Gracilaria confervoides, and related red algae. It is used as a gel in the preparation of solid culture media for microorganisms, as a bulk laxative, in making emulsions, and as a supporting medium for immunodiffusion and immunoelectrophoresis.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.Iatrogenic Disease: Any adverse condition in a patient occurring as the result of treatment by a physician, surgeon, or other health professional, especially infections acquired by a patient during the course of treatment.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.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.Liver Neoplasms: Tumors or cancer of the LIVER.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.Communications Media: The means of interchanging or transmitting and receiving information. Historically the media were written: books, journals, newspapers, and other publications; in the modern age the media include, in addition, radio, television, computers, and information networks.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Aortography: Radiographic visualization of the aorta and its branches by injection of contrast media, using percutaneous puncture or catheterization procedures.Infertility, Female: Diminished or absent ability of a female to achieve conception.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.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.Kidney Function Tests: Laboratory tests used to evaluate how well the kidneys are working through examination of blood and urine.Acute Disease: Disease having a short and relatively severe course.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.Bismuth: A metallic element that has the atomic symbol Bi, atomic number 83 and atomic weight 208.98.Dextrans: A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.Coronary Vessels: The veins and arteries of the HEART.Spinal DiseasesSalicylates: The salts or esters of salicylic acids, or salicylate esters of an organic acid. Some of these have analgesic, antipyretic, and anti-inflammatory activities by inhibiting prostaglandin synthesis.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.Magnetics: The study of MAGNETIC PHENOMENA.Renal Circulation: The circulation of the BLOOD through the vessels of the KIDNEY.Renal Dialysis: Therapy for the insufficient cleansing of the BLOOD by the kidneys based on dialysis and including hemodialysis, PERITONEAL DIALYSIS, and HEMODIAFILTRATION.Equipment Design: Methods of creating machines and devices.Blood Urea Nitrogen: The urea concentration of the blood stated in terms of nitrogen content. Serum (plasma) urea nitrogen is approximately 12% higher than blood urea nitrogen concentration because of the greater protein content of red blood cells. Increases in blood or serum urea nitrogen are referred to as azotemia and may have prerenal, renal, or postrenal causes. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)Heart Septal Defects, Atrial: Developmental abnormalities in any portion of the ATRIAL SEPTUM resulting in abnormal communications between the two upper chambers of the heart. Classification of atrial septal defects is based on location of the communication and types of incomplete fusion of atrial septa with the ENDOCARDIAL CUSHIONS in the fetal heart. They include ostium primum, ostium secundum, sinus venosus, and coronary sinus defects.Bacteriological Techniques: Techniques used in studying bacteria.Coronary Artery Disease: Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.PolysaccharidesEndoscopy: Procedures of applying ENDOSCOPES for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. transluminal, to examine or perform surgery on the interior parts of the body.Recurrence: The return of a sign, symptom, or disease after a remission.Intraoperative Care: Patient care procedures performed during the operation that are ancillary to the actual surgery. It includes monitoring, fluid therapy, medication, transfusion, anesthesia, radiography, and laboratory tests.Free Radical Scavengers: Substances that influence the course of a chemical reaction by ready combination with free radicals. Among other effects, this combining activity protects pancreatic islets against damage by cytokines and prevents myocardial and pulmonary perfusion injuries.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.Kidney Cortex: The outer zone of the KIDNEY, beneath the capsule, consisting of KIDNEY GLOMERULUS; KIDNEY TUBULES, DISTAL; and KIDNEY TUBULES, PROXIMAL.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.Constriction, Pathologic: The condition of an anatomical structure's being constricted beyond normal dimensions.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Histamine Release: The secretion of histamine from mast cell and basophil granules by exocytosis. This can be initiated by a number of factors, all of which involve binding of IgE, cross-linked by antigen, to the mast cell or basophil's Fc receptors. Once released, histamine binds to a number of different target cell receptors and exerts a wide variety of effects.Risk Assessment: The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)Iodine Radioisotopes: Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.Kidney Failure, Chronic: The end-stage of CHRONIC RENAL INSUFFICIENCY. It is characterized by the severe irreversible kidney damage (as measured by the level of PROTEINURIA) and the reduction in GLOMERULAR FILTRATION RATE to less than 15 ml per min (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002). These patients generally require HEMODIALYSIS or KIDNEY TRANSPLANTATION.