Diagnosis of horseshoe kidney not shown on ultrasound but clearly visualized by renal scintigraphy.
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Diagnosis, Differential↗
Biomedical subjects
D Margouleff
Publications and source records attributed to D Margouleff.
Effects of Out-of-Field Radiation on Dual-Head Gamma Camera Imaging in Coincidence Mode.
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Journal Article↗
Radiosynthesis of [18F] N-3-fluoropropyl-2-beta-carbomethoxy-3-beta-(4-iodophenyl) nortropane and the first human study with positron emission tomography.
A procedure for the routine preparation of [18F]FP-CIT has been developed. Purification of the final product was achieved by preparative HPLC using phenethyl column without decomposition or epimerization. [18F] labeled-N-fluoropropyl-2 beta-carbomethoxy-3 beta-(4-iodophenyl) nortropane was prepared and PET imaging was performed on human subjects. A high uptake into striatal regions was observed. HPLC plasma analysis using [18F]FP-CIT indicated the presence of only one metabolite. By directly comparing the behavior of these three radiotracers ([18F]DOPA, [123I]FP-CIT, and [18F]FP-CIT) in the same subjects, we can enhance our understanding of the dopaminergic system as well as the relative potential of these techniques in a clinical research setting.
Chromatography, High Pressure Liquid↗
Discrepancies in thyroid uptake values, use of commercial thyroid probe systems versus scintillation cameras.
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Gamma Cameras↗
Bladder wall radiation dose in humans from fluorine-18-FDOPA.
UNLABELLED: PET, in conjunction with 18F-fluorodopa (FDOPA), has become the standard technique to assess basal ganglia degeneration in patients with movement disorders. Based on published dosimetry data, the injected dose of FDOPA is limited to 111 Mbq (3 mCi) because of exposure to the bladder wall, which is the critical organ for such studies. These dosimetry studies are based on mathematical models for the bladder radioactivity accumulation and clearance when the subjects were asked to void approximately 2 hr after the intravenous injection of FDOPA. In this study, we improved the radiation dose estimate to the bladder wall using dynamic PET to image the bladder during the uptake phase as well as before and after voiding. METHODS: The subjects were tested on a new protocol. They were hydrated preinjection and given a first bladder void break at 40 min postinjection and a second void at the end of study at 120 min. RESULTS: The MIRD model, applied to the data collected from 10 adults of both sexes, yielded an average absorbed dose of 0.15 +/- 0.08 mGy/MBq (0.57 +/- 0.28 rad/mCi). CONCLUSION: This absorbed dose is significantly lower than previous estimates and allows for FDOPA injections up to 333 Mbq (9 mCi).
Adult↗
Hepatobiliary scintigraphy after biliary tract surgery.
Hepatobiliary scintigraphy provides a rapid, noninvasive, accurate means of assessing patients after biliary tract surgery. This is especially important, given the high incidence of biliary and enteric diseases. In this review article, the role of radionuclide imaging in postcholecystectomy and postgastroenteric surgery patients will be examined, as well as following invasive procedures and trauma.
Adult↗
Scintigraphic cerebral spinal fluid leak study in a child with recurrent meningitis after resection of a frontal meningocele.
An In-111 DTPA cerebrospinal fluid (CSF) leak study was performed on a 3-year-old boy admitted with recurrent meningitis. He was born with a congenital encephalocele that was surgically resected at 7 days-of-age. A residual skull floor defect with a recurrent tumor of the nasal radix was clinically suspected. Computed tomography and MRI scans could not confirm or rule out the presence of a CSF leak. The scintigraphic study clearly demonstrated a leak into the left naris. A large leptomeningeal cyst extending down into the left nares was resected and a defect in the left frontal calvarium, identified as the source of the CSF leak, was repaired at surgery.
Arachnoid Cysts↗
Assessment of disease severity in parkinsonism with fluorine-18-fluorodeoxyglucose and PET.
UNLABELLED: Fluorine-18-fluorodeoxyglucose (FDG) and PET have been used to identify an abnormal regional metabolic covariance pattern in Parkinson's disease (PD). To examine the potential use of this covariance pattern as a metabolic imaging marker for PD, we describe the Topographic Profile Rating (TPR), which is a method for calculating subject scores for this pattern in individual PD patients. We then assess the relationship between these metabolic measures and objective independent disease severity ratings. METHODS: Two independent groups of PD patients were studied with FDG-PET. Group A consisted of 23 patients (mean age 60.2 +/- 12.2; mean Hoehn and Yahr stages 2.4 +/- 1.3) and Group B had 14 patients (mean age 49.0 +/- 12.1; mean Hoehn and Yahr stage 3.2 +/- 1.2). The regional cerebral metabolic rates for glucose (rCMRGlc) in all patients in each group were measured. TPR was used to calculate subject scores for the disease-related covariance pattern on a patient-by-patient basis. RESULTS: In both PD patient groups, subject scores correlated with Hoehn and Yahr disease severity ratings (Group A: r = 0.59, p < 0.004; Group B: 0.57, p < 0.04), quantitative ratings for bradykinesia (Group A: r = 0.63, p < 0.002; Group B: r = 0.61, p < 0.03), rigidity (Group A: r = 0.59, p < 0.004; Group B: r = 0.59, p < 0.04), but not with tremor. CONCLUSION: These findings indicate that regional metabolic covariance patterns are robust imaging markers of disease severity. FDG-PET may be useful clinically in assessing parkinsonian disability and disease progression.
Adult↗
The metabolic topography of parkinsonism.
We used [18F]fluorodeoxyglucose/positron emission tomography (18F-FDG/PET) and a statistical model of regional covariation to study brain topographic organization in parkinsonism. We studied 22 patients with Parkinson's disease (PD), 20 age-matched normal volunteers, and 10 age- and severity-matched patients with presumed striatonigral degeneration (SND). We used FDG/PET to calculate global, regional, and normalized metabolic rates for glucose (GMR, rCMRglc, rCMRglc/GMR). Metabolic parameters in the three groups were compared using an analysis of variance, with a correction for multiple comparisons, and discriminant analysis. The scaled subprofile model (SSM) was applied to the combined rCMRglc dataset to identify topographic covariance profiles that distinguish PD patients from SND patients and normals. GMR, rCMRglc, and rCMRglc/GMR were normal in PD; caudate and lentiform rCMRglc/GMR was reduced in the SND group (p < 0.01). SSM analysis of the combined group of patients and normals revealed a significant topographic profile characterized by increased metabolic activity in the lentiform nucleus and thalamus associated with decreased activity in the lateral frontal, paracentral, inferior parietal, and parietooccipital areas. Individual subject scores for this profile were significantly elevated in PD patients compared with normals and SND patients (p < 0.001) and discriminated the three groups. In the PD group, subject scores for this factor correlated with individual subject Hoehn and Yahr (H & Y) scores (p < 0.02), and with quantitative rigidity (p < 0.01) and bradykinesia (p < 0.03) ratings, but not with tremor ratings. SSM analysis of right-left metabolic asymmetries yielded a topographic contrast profile that accurately discriminated mildly affected PD patients (H & Y Stage I) from normals. Our findings demonstrate that abnormal topographic covariance profiles exist in parkinsonism. These profiles have potential clinical application as neuroimaging markers in parkinsonism.
Adult↗
Quantitative brain FDG/PET studies using dynamic aortic imaging.
Positron emission tomography (PET) measurements of cerebral glucose utilization using 18F-fluorodeoxyglucose (FDG) are a useful tool in the investigation of localized brain function in normal and disease states. A major impediment to the application of FDG/PET in clinical investigation has been the need for arterial blood sampling to quantify cerebral glucose metabolism (CMRGlc). Qualitative studies, though informative in a variety of clinical settings, are of limited value for research applications and do not utilize the inherent quantitative nature of PET. We present a novel PET technique employing a whole-body PET tomograph with abdominal aortic imaging from 0 to 30 min as an alternative to arterial blood sampling to obtain the input function for cerebral metabolic rate calculations. Two or three arterial samples taken during the 10-45 min period were used to scale and extend the blood curve and the brain was imaged from 35-55 min post-injection. We performed 12 studies in which both arterial blood sampling and aortic scans were obtained. We found the correlation of global metabolic rates (GMR) when comparing the two techniques to be extremely high (R2 = 0.99). This suggests that the use of dynamic aortic imaging is less invasive and a viable alternative to arterial blood sampling in quantitative FDG/PET imaging.
Algorithms↗
Striatal hypometabolism distinguishes striatonigral degeneration from Parkinson's disease.
Regional and global metabolic rates for glucose were estimated using 18F-fluorodeoxyglucose and positron emission tomography in 10 patients with a clinical likelihood of striatonigral degeneration (2 men and 8 women; mean age, 61.8 +/- 6.9 years; mean disease duration, 4.7 +/- 2.2 years; mean Hoehn and Yahr score, 3.5 +/- 0.8). Measures of brain glucose metabolism in these patients were compared with those for 10 age-matched normal volunteers, 10 disease severity-matched patients with Parkinson's disease (PD), and 10 disease duration-matched patients with PD. Normalized glucose metabolism was significantly reduced in the caudate (p < 0.03) and putamen (p < 0.003) as compared with that in normal and PD control subjects, and discriminated patients with striatonigral degeneration from control subjects (p < 0.002). Putamenal hypometabolism in patients with striatonigral degeneration correlated significantly with quantitative ratings of motor disability (p < 0.02). These results suggest that quantitative 18F-fluorodeoxyglucose positron emission tomography techniques may be useful in supporting a diagnosis of striatonigral degeneration in life, and in objectively assessing disease severity and potential therapeutic interventions.
Aged↗
Positron emission tomographic findings in Filipino X-linked dystonia-parkinsonism.
Regional and global metabolic rates for glucose (rCMRGlc and GMR) were estimated using [18F]fluorodeoxyglucose and positron emission tomography in 3 patients with Filipino X-linked dystonia-parkinsonism (lubag). In all 3 patients a selective reduction in normalized striatal glucose metabolism (rCMRGlc/GMR) was observed compared with 15 normal volunteer subjects. Presynaptic nigrostriatal function was assessed in these patients using [18F]fluorodopa and positron emission tomography. Striatal rate constants for [18F]flurodopa uptake were found to be in the normal range in all 3 patients with lubag. These findings suggest that the extrapyramidal manifestations of lubag are metabolically localized to the striatum and that clinical parkinsonism in these patients may be secondary to extranigral factors.
Adult↗
Striatal 18F-dopa uptake: absence of an aging effect.
L-[18F]6-Fluoro-DOPA (L-[18F]6-fluoro-3,4-dihydroxyphenylalanine; FDOPA) has been used with quantitative positron emission tomography (PET) to assess presynaptic nigrostriatal dopaminergic function in life. The relationship of estimated kinetic rate constants for striatal FDOPA uptake [Ki(FDOPA)] to the normal aging process has been the subject of conflicting reports. Resolution of this issue has been hampered by methodological differences in previous FDOPA/PET investigations. We studied 19 healthy normal subjects (aged 27-77 years) and measured striatal Ki-(FDOPA) according to each of the earlier methods. While significant correlations (p < 0.005) existed between Ki(FDOPA) values estimated by the various techniques, none correlated with normal aging. We conclude that normal striatal Ki(FDOPA) values estimated using quantitative FDOPA/PET are uncorrelated with the aging process.
Adult↗
Noninvasive quantitative fluorodeoxyglucose PET studies with an estimated input function derived from a population-based arterial blood curve.
The authors have developed a technique to estimate input functions from a population-based arterial blood curve in positron emission tomography (PET) studies with fluorine-18 fluorodeoxyglucose (FDG). A standardized pump injection was used in 34 subjects. A population-based blood curve was generated based on the first 10 subjects. In the remaining 24 subjects, an estimated input function (EIFa) was obtained by scaling the population-based curve with two arterial blood samples, one obtained at 10 minutes and the other at 45. Time integrals for EIFa and the real arterial input function (RIF) were in excellent agreement (r = .998, P < .0001). Cerebral metabolic rates for glucose calculated with EIFa and RIF and the autoradiographic method also correlated excellently (r = .992, P < .0001). Analogous correlations were achieved with arterialized venous samples as scaling factors. These results suggest that individually scaled, population-derived input functions may serve as an adequate alternative to continuous arterial blood sampling in quantitative FDG-PET imaging.
Adult↗
The use of a new radiopharmaceutical, 97Ru-DISIDA, and of 99Tcm-sulphur colloid for the simultaneous evaluation of duodenogastric reflux and gastric emptying.
There is no consensus or a uniform technique for measuring gastric emptying and numerous modalities have been reported. We report here the results obtained using a modification of the published techniques for the simultaneous measurement of duodenogastric reflux and gastric emptying utilizing simultaneously the recently developed radiopharmaceutical 97Ru-DISIDA, intravenously, and the oral administration of 99Tcm-sulphur colloid incorporated in a 'solid' test meal.
Administration, Oral↗
Reversible functional asplenia in systemic lupus erythematosus.
A 44-year-old woman with a history of systemic lupus erythematosus on no steroid or immunosuppressive medication presented in septic shock complicated by renal failure and disseminated intravascular coagulation. The patient was treated with antibiotics. Liver-spleen scintigraphy with Tc-99m albumin colloid initially failed to reveal tracer accumulation in the spleen. Follow-up study after one year revealed normal tracer uptake in the spleen. The transient blockade of reticuloendothelial system by immune complexes is the most likely mechanism. Other possible mechanisms include disturbed vascular supply due to thrombosis secondary to the disseminated intravascular coagulation or vasculitis.
Adult↗
Performance characteristics of a commercial dedicated contamination counter.
The dedicated wipe test counter (DWTC) is a commercial geiger-counter type instrument especially designed for wipe test counting. All samples are counted under the same physical conditions within 0.3 cm from a 2-mg cm-2 mica end-window geiger tube of 1.27 cm in diameter. The counting capabilities of the DWTC were tested for different radioisotopes in common use in the nuclear medicine laboratory. Since most of the imaging agents are 99mTc-based radiopharmaceuticals, an experimental efficiency factor, J = 3 cpm kdpm-1, was determined for this radioisotope by the manufacturer and stored in the counting system for default use. In addition, the formulation for the counting time needed to achieve a measurement with adequate level of significance (two standard deviations) and a background measurement time of 20 min was programmed in the firmware of the DWTC. With these parameters, the counting time for a 99mTc wipe (threshold of 2000 dpm) becomes 1.88 min for a background level of 10 cpm. The counting time increases to 3.25 and 4.80 min for the respective background levels of 20 and 30 cpm while the threshold is kept the same. In practice, we were able to measure activities as low as 0.7 kdpm for 99mTc and 0.09 kdpm for 131I. Linearity was maintained for a wide range of activities for all tested radioisotopes. The DWTC was found to be simple to operate and satisfies all requirements for performing wipe tests in the nuclear medicine laboratory.
Evaluation Studies as Topic↗
Scintigraphic evaluation of postoperative complications of laparoscopic cholecystectomy.
Laparoscopic cholecystectomy is gaining popularity as an alternative to standard open cholecystectomy. At our institution, approximately 400 laparoscopic cholecystectomies have been performed since May 1989. The frequency of major postoperative complications has been approximately 1.5% (6 out of 400 cases). The most common complications have been biliary tree injury, bile leak, and retained stone. We present three patients who developed postoperative complications that were properly diagnosed on 99mTc-DISIDA cholescintigraphy. Our report indicates that 99mTc-DISIDA scintigraphy facilitates the rapid and precise diagnosis of bile leaks in patients with abdominal pain and/or hyperbilirubinemia following laparoscopic cholecystectomy.
Adult↗