Segmental colonic transit after oral 67Ga-citrate in healthy subjects and those with chronic idiopathic constipation.
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Measurement of segmental colonic transit is important in the assessment of patients with severe constipation. 111In-diethylenetriamine pentaacetic acid (DTPA) has been established as the tracer of choice for these studies, but it is expensive and not readily available. 67Ga-citrate is an inexpensive tracer and when given orally is not absorbed from the bowel. It was compared with 111In-DTPA in colonic transit studies in nonconstipated control subjects and then in patients with idiopathic constipation. METHODS: Studies were performed after oral administration of 3 MBq (81 microCi) 67Ga-citrate or 4 MBq (108 microCi) 111In-DTPA in solution. Serial abdominal images were performed up to 96 h postinjection, and computer data were generated from geometric mean images of segmental retention of tracer, mean activity profiles and a colonic tracer half-clearance time. RESULTS: There were no differences in segmental retention of either tracer or in mean activity profiles between control subjects and constipated patients. Results in constipated subjects were significantly different from those in controls. The mean half-clearance times of tracer for control subjects were 28.8 h for 67Ga-citrate and 29.9 h for 111In-DTPA in control subjects and 75.0 h for 67Ga-citrate and 70.8 h for 111In-DTPA in constipated patients. CONCLUSION: Oral 67Ga-citrate can be used as a safe alternative to 111In-DTPA for accurate measurement of segmental colonic transit. (+info)
Gallium-67 scintigraphy and intraabdominal sepsis. Clinical experience in 140 patients with suspected intraabdominal abscess.
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In 140 patients with suspected intraabdominal abscess, studies were made using gallium-67 citrate and technetium-99m labeled radiopharmaceuticals. Gallium-67 scintigrams correctly localized 52 of 56 intraabdominal abscesses confirmed at surgical operation or necropsy. In an additional 20 patients in whom findings on scintigrams were abnormal, there were clinically established infections. Sixty-one patients in whom findings on scintigrams were normal were conservatively managed and discharged from the hospital; none proved to have an abscess. Four false-negative and three false-positive studies were recorded. Gallium-67 scintigraphy is a useful noninvasive diagnostic adjunct that should be employed early in the evaluation of patients with suspected intraabdominal sepsis. (+info)
Probable lymphocytic hypophysitis diagnosed by short-term serial computed tomography and gallium-67 scintigraphy--case report.
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A 61-year-old female presented with headache, malaise, and left oculomotor nerve paralysis. Computed tomography (CT) demonstrated a diffuse pituitary mass and enlarged pituitary stalk with homogeneous contrast enhancement. Her symptoms gradually resolved without treatment. Gallium-67 scintigraphy showed abnormal uptake in the pituitary lesion. Serial CT every 2 weeks after admission showed homogeneous contrast enhancement and shrinking of the pituitary mass to a normal size 12 weeks after the onset. The final diagnosis was lymphocytic adenohypophysitis without biopsy. Recurrence has not been observed for 8 years after discharge. The patient did not need hormone replacement therapy. Histological examination is not always necessary to diagnose probable lymphocytic adenohypophysitis with the characteristic feature of rapid onset, abnormal gallium-67 uptake in the lesion, and resolution of symptoms in the acute stage with shrinking of the lesion on neuroimaging. (+info)
Myositis ossificans demonstrated by positive gallium-67 and technetium-99m-HMDP bone imaging but negative technetium-99m-MIBI imaging.
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Gallium-67-citrate and 99mTc-diphosphate bone imaging agents are localized in myositis ossificans, a tumor-like benign soft-tissue mass that makes it impossible to differentiate between malignant tumor and the infection/inflammatory process. We present such a myositis ossificans patient whose bone and 67Ga-citrate imagings showed increased uptake in the left thigh and two foci of the right gluteal region leading to inconclusive results. Technetium-99m-MIBI imaging showed the absence of substantial uptake in these regions. ACT scan confirmed myositis ossificans. The lack of 99mTc-MIBI uptake in myositis ossificans means that 99mTc-MIBI imaging may be useful in the differential diagnosis. (+info)
Radiation exposure from gallium-67-citrate patients.
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OBJECTIVE: Serial monitoring of patients was performed to determine the radiation exposure contributed by patients injected with 67Ga-citrate to their surroundings. Radiology and nursing staff distance exposure estimates were made for various patient care tasks and imaging tests. METHODS: Fifteen adult patients were surveyed early (mean 4.3 min) and 11 of the 15 were surveyed at 3 d (mean 68.8 h) postinjection. The standard adult lymphoma imaging activity of 333-407 MBq (9-11 mCi) resulted in a range of 3.7-8.1 MBq/kg (0.1-0.22 mCi/kg). Dose rate measurements were made in the anterior, posterior, and left and right lateral projections at the level of the umbilicus, at distances of patient's surface and at 30.5 cm and 100 cm with a calibrated ion chamber. Time of contact-routine task analyses also were obtained for nursing and radiology personnel. Using a radiation survey-derived biexponential pharmacokinetic relationship, radiation exposures were determined for hospital personnel and family members at various times after injection. RESULTS: Based on the study population survey results, the mean instantaneous exposures (microSv/h) for an administered activity of 370 MBq (10 mCi) 67Ga-citrate were determined. The task analyses revealed the maximum patient contact time for any procedure performed at a distance equal to, or less than, 30.5 cm was 30 min. CONCLUSION: The quantitation of radiation exposure scenarios from 67Ga-citrate patients has determined that no special precautions are necessary for medical personnel when performing routine tasks associated with these patients. (+info)
Paraganglioma in the frontal skull base--case report.
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A 56-year-old female presented with a paraganglioma in the left anterior cranial fossa who manifesting as persistent headache. Computed tomography and magnetic resonance imaging showed a solid, enhanced tumor with a cystic component located medially. The tumor was attached to the left frontal base and the sphenoid ridge. Angiography demonstrated a hypervascular tumor fed mainly by the left middle meningeal artery at the left sphenoid ridge. The preoperative diagnosis was meningioma of the left frontal base. The tumor was totally resected via a left frontotemporal craniotomy. Histological examination revealed the characteristic cellular arrangement of paraganglioma generally designated as the "Zellbaren pattern" on light microscopy. Only 10 patients with supratentorial paraganglioma have been reported, seven located in the parasellar area. The origin of the present tumor may have been the paraganglionic cells which strayed along the middle meningeal artery at differentiation. (+info)
Enhanced uptake of [11C]TPMP in canine brain tumor: a PET study.
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In vitro studies have demonstrated the membrane potential-dependent enhanced uptake of phosphonium salts, including [3H]triphenylmethylphosphonium (TPMP), into mitochondria of carcinoma and glioma-derived tumor cells, suggesting the potential use of phosphonium salts as tracers for tumor imaging. This study characterizes the in vivo uptake of [11C]TPMP in canine brain glioma using PET. METHODS: Dynamic paired PET studies of [11C]TPMP followed by [68Ga]ethylenediaminetetraacetic acid (EDTA) were performed 4 d before and 9 d after tumor cell inoculation. Graphical analysis was used to evaluate [11C]TPMP retention in tumor tissue. Distribution of tracer uptake was compared with tumor histological sections. RESULTS: [11C]TPMP exhibited enhanced uptake and prolonged retention in tumor cells. Patlak plot was linear over the 20- to 95-min postinjection period (r = 0.97 +/- 0.1). [68Ga]EDTA exhibited a gradual washout from the tumor tissue. The tumor-to-normal brain uptake ratio at 55 to 95 min postinjection was 47.5 for [11C]TPMP and 8.1 for [68Ga]EDTA. Qualitative comparison with histological sections indicated that [11C]TPMP enhanced uptake was restricted to the tumor area. CONCLUSION: The enhanced uptake and prolonged retention in tumor suggest [11C]TPMP as a promising means for imaging of gliomas in dogs. The need for studies in humans is indicated. (+info)
Reduced size of liquefaction necrosis of mitral annular calcification in chronic renal failure by using low calcium concentration hemodialysis.
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A report is presented of a liquefaction necrosis of mitral annular calcification in a patient with chronic renal failure and secondary hyperparathyroidism who had been managed by hemodialysis for 11 years. The mass was echogenic with an echo-lucent area inside, high density on computed tomography and low intensity on magnetic resonance imaging. The uptake of gallium-67 (67Ga)-citrate and the bone agent technetium-99m-methylene diphosphate (99mTc-MDP) was seen in the mass. These findings were compatible with liquefaction necrosis of the mitral annular calcification. After treatment with low calcium concentration hemodialysis, the size of the mass reduced with disappearance of the echo-lucent area on the echocardiography and there was no uptake of 67Ga-citrate or 99mTc-MDP. Liquefaction necrosis might be the early and reversible form of mitral annular calcification. When a tumorlike echogenic mass at the base of mitral leaflets is seen in patients with predisposing factors for mitral annular calcification, consider the possibility of this specific form of mitral annular calcification in order to avoid any unnecessary surgical intervention. (+info)