Computerized axial tomography: the normal EMI scan.
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Computerized axial tomography using the EMI scanner as a new method of using x-rays in diagnosis. The technique displays intracranial and orbital structures in the transverse plane. The appearances of normal EMI Scans are described and correlated with cerebral and orbital anatomy seen in transverse section. (+info)
Standardized annotation of nuclear medicine images.
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There are no generally accepted standards for annotating nuclear medicine images. This is a potential problem whenever hardcopies from other centers are being evaluated, reinterpreted or compared to actual images of the same patient. Proposals for image annotation are elaborated to support image evaluation by a third party. In this paper, examples are given of lung scintigraphy, thyroid scintigraphy, bone scintigraphy both in planar and SPECT techniques, renal function scintigraphy, myocardial perfusion scintigraphy, and PET. They are presented to stimulate discussion in the nuclear medicine community. (+info)
Cranial MR imaging of osteopetrosis.
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BACKGROUND AND PURPOSE: The purpose of this study was to describe the cranial MR imaging manifestations of osteopetrosis. These features have not previously been reported in the literature. METHODS: Cranial MR studies, obtained with a uniform imaging protocol, were reviewed in 47 patients with osteopetrosis. Thirty-four patients had autosomal recessive (malignant) osteopetrosis (AROP), seven had intermediate osteopetrosis (IOP), and six had either type I or type II autosomal dominant osteopetrosis (ADOP I or II). The prevalence of abnormalities was tabulated and compared with the specific osteopetrosis variants. RESULTS: All patients with osteopetrosis had thickening and sclerosis of the calvaria. Ventriculomegaly, tonsillar herniation, proptosis, and dural venous sinus stenosis were observed in the majority of patients with AROP and ADOP I. Optic nerve sheath dilatation occurred in many of the patients with AROP and in all patients with ADOP I. Acquired cephaloceles were also observed only in these two groups. Optic nerve atrophy and optic canal stenosis were observed in a majority of patients with AROP, IOP, and ADOP II. Middle ear fluid was prevalent in AROP and IOP, present in over half the patients in each group. Features seen most prevalently, or exclusively, in AROP included stenosis of the internal carotid and vertebral arteries and extramedullary hematopoiesis. CONCLUSION: The cranial MR imaging features of osteopetrosis are both shared and unique among the various subtypes of the disease. The specific cranial and intracranial manifestations reflect the predominant calvarial or skull base patterns of bone thickening. The unique features seen in patients with AROP probably reflect the early age of onset and the greater severity of this form of the disease. (+info)
Motilides accelerate regional gastrointestinal transit in the dog.
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BACKGROUND: Motilides have prokinetic effects on the upper gut during fasting, increasing the strength of antral contractions and stimulating gastroduodenal phase 3 sequences. Effects on the distal gut, and postprandially, are less well documented. AIM: To evaluate dose-response effects of motilin and erythromycin on gastric emptying, small bowel and colonic transit in the dog using a validated scintigraphic technique. METHODS: For gastric emptying and small bowel transit, 99mTc labelled beads were added to a meal of dog chow (450 kcal). Regional colonic transit was measured by 111In labelled beads placed in a capsule which dissolved and released radiation into the proximal colon. Scintiscans were taken at regular intervals and indices of whole-gut transit were calculated. Drugs were given by slow intravenous administration. RESULTS: In the doses used, motilin accelerated regional colonic transit but did not hasten gastric emptying or small bowel transit. Single or repeated doses of motilin had similar effects on colonic transit. Erythromycin accelerated gastric emptying, small bowel transit and regional colonic transit. CONCLUSIONS: Motilin receptors are apparently present in the canine small bowel and colon. Postprandially, motilides accelerate transit in the distal gut. (+info)
A comparison of 111In with 52Fe and 99mTc-sulfur colloid for bone marrow scanning.
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Under most circumstances 52Fe, 111In, and colloid show a similar distribution of marrow. The lesser uptake of 111In by liver and spleen may occasionally be of value in permitting visualization of that portion of the spinal marrow obscured by these organs in the colloid scan. However, in red cell aplasia, when there is dissociation between phagocytic and erythropoietic functions, scanning with 111In gives no information about erythropoietic tissue distribution. Therefore, indium cannot be used as an analog for iron in the study of the hematopoietic system. (+info)
Gallium-67-citrate scanning for the localization and staging of lymphomas.
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One-hundred-eight 67Ga-citrate scans were evaluated in Hodgkin's and non-Hodgkin's lymphomas for staging, diagnosis of recurrence, and for determing the results of treatment. Accuracy as confirmed by comparing the scans with pathologic material or roentgenologic and clinical findings was found to be 83%. Known lymph node involvement was diagnosed correctly in 87% but accuracy was only 48% for extranodal areas. Bone lesions were diagnosed correctly in 83% compared with only 48% of lesions of the lungs and liver. Scans were 75% accurate in 28 patients scanned for initial staging. False negatives were present in 12%; recurrent tumor in an area of prior radiation therapy appeared to be the most common cause. There were 5% false positives. Gallium scanning is a useful adjunct to other methods of detecting lymphoma. (+info)
Reconstruction of the Fresnel-coded gamma camera images by digital computer.
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An algorithm for the digital reconstruction of the Fresnel-coded gamma camera image consists of the spatial Fourier transform of the hologram after applying a quadratic phase shift. Background subtraction is implemented by use of positive and negative zone plates. Tomographic planes are reconstructed in 27 sec from a single zone-plate shadow image by successively varying a parameter in the reconstruction algorithm on a small computer system. (+info)
Recombinant versus natural human 111In-beta2-microglobulin for scintigraphic detection of Abeta2m amyloid in dialysis patients.
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BACKGROUND: We previously introduced scintigraphy with 131I-labeled beta2-microglobulin (beta2m), purified from uremic hemofiltrate, that is, "natural" beta2m, to specifically detect beta2m-associated amyloidosis (Abeta2m) in hemodialysis (HD) patients. METHODS: To improve the safety and resolution of the scan, we covalently bound the chelator diethylenetriaminepentaacetic acid to natural beta2m to allow radiolabeling with 111In. In a second step, we generated and evaluated the usage of recombinant human beta2m (rhbeta2m) for scintigraphy. RESULTS: Using natural 111In-labeled beta2m, eight patients on HD for 0 to 17 years, without evidence of Abeta2m, were scanned. Whole-body scintigraphy at 48 to 72 hours postinjection revealed no significant tracer accumulation over joint regions. In contrast, nine patients on HD for 10 to 21 years with clinical, radiological, or histologic (N = 4) evidence of Abeta2m showed selective tracer uptake over various joint regions. Tracer accumulation in visceral organs, which could not be related to tracer elimination or metabolism, was not detected. Compared with the previous 131I beta2m scan, scintigraphy with 111In-labeled beta2m offered highly improved image contrast, increased sensitivity, and a 50 to 70% reduction of the radiation exposure. Scanning with 111In-labeled recombinant human beta2m was performed in six patients: No significant tracer accumulation was observed over joint regions in two patients on short-term HD without evidence of Abeta2m; in contrast, local tracer accumulations similar to those observed with natural beta2m could be demonstrated in four long-term (10 to 27 years) HD patients with clinical, radiological, and histologic (N = 1) evidence of Abeta2m. CONCLUSION: Scintigraphy for Abeta2m with 111In-labeled rhbeta2m provides a homogenous and safe recombinant protein source and leads to enhanced sensitivity and lower radiation exposure. (+info)