摘要:

PurposeThe assessment of gallbladder function and ejection fraction using sincalide-enhanced biliary scintigraphy is a useful way to evaluate patients with recurrent right upper quadrant pain but no gallstones.Materials and MethodsWe wanted to determine whether gallbladder contraction measured by ultrasonography could be used in place of biliary scintigraphy. Biliary scans with an infusion of sincalide and concurrent ultrasonography were performed in 17 patients with histories of recurrent abdominal pain and no evidence of gallstones by ultrasound.ResultsGallbladder ejection fractions calculated by ultrasound and scintigraphy using standard techniques showed only a weak correlation. The poor performance of ultrasound appears to arise because the variable shape of the gallbladder invalidates the calculation of its volume by the formula for a prolate spheroid. When gallbladders that were ellipsoidal were subselected, correlation was improved. The level of training of the sonologist did not have a significant effect on the results.ConclusionGallbladder ejection fraction calculated by ultrasonography cannot be used routinely as a substitute for biliary scintigraphy.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

PurposeDiagnosing brain death is important in managing the comatose patient for whom the continuation of life support is being questioned and when organ harvesting is being considered. The virtual immediate localization of Tc-99m HMPAO to cerebral and cerebellar tissue provides an index of blood perfusion, and its absence denotes brain death. Other methods for assessing brain death include cerebral angiography, MRI, CT imaging after inhalation of stable xenon, electroencephalography, and clinical examination. The contrast material used for angiography may damage harvested organs, and the other studies have significant errors. MRI, CT imaging, and angiography are unsuitable for bedside use.MethodsTwenty-three patients, who presented with head trauma, prolonged anoxia or intrinsic brain disease (e.g., glioblastoma multiforme) and who were brain-dead by clinical examination criteria, were referred to the nuclear medicine division for verification of brain death. For adults, approximately 25 mCi Tc-99m hexamethylpropylene amineoxime (HMPAO) was administered intravenously. All patients but one were imaged using a mobile scintillation camera at the bedside.ResultsWe demonstrated (1) both cerebral and cerebellar perfusion, (2) neither cerebral nor cerebellar perfusion, (3) cerebral without cerebellar perfusion, and (4) cerebellar without cerebral perfusion. Patients without cerebral perfusion were diagnosed as brain-dead. The significance of a viable cerebellum in the absence of cerebral viability was not fully appreciated, although organs were harvested from such patients. We determined how well the clinical examination criteria held up in the diagnosis of brain death against the new gold standard of Tc-99m HMPAO scintigraphy: Clinical examination criteria correctly predicted brain death only 83% of the time compared with HMPAO scintigraphy.ConclusionsBrain death assessment by Tc-99m HMPAO scintigraphy has proved to be a reliable, safe, and cost-effective bedside method and may have practical application in the assessment of brain death in potential cadaveric donors.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

PurposeWhen the cerebral metabolic rate of glucose (CMRglc) is to be measured, arterial blood sampling is usually required for fluorine-18 fluorodeoxyglucose (FDG) and positron emission tomography (PET) studies. However, blood sampling is inconvenient because it requires several staff members and is invasive for patients.MethodsTo assess cerebral glucose metabolism by a noninvasive and simplified method, the authors used the standardized uptake value (SUV), which requires no input function or blood sampling. The study participants included 18 healthy volunteers (4 men and 14 women; mean ± SD age, 68.2 ± 6.3 years), 18 patients with mild Alzheimer’s disease (AD) (4 men and 14 women; mean ± SD age, 68.8 ± 7.3 years), and 18 patients with moderate AD (5 men and 13 women, mean ± SD age, 69.5 ± 8.5 years). Regional CMRglc and regional cerebral SUV were measured in the three groups using FDG PET, and the correlation between global CMRglc and global SUV was estimated.ResultsThe correlation coefficients of global CMRglc and global SUV in the healthy volunteers, mild AD patients, and moderate AD patients were 0.82, 0.67, and 0.62, respectively. Compared with the healthy persons, the patients with mild AD showed significantly decreased CMRglc in the temporal, frontal, and parietal cortices, but they did not show significantly decreased SUV in any region. Patients with moderate AD had significantly decreased CMRglc in the temporal, frontal, occipital, parietal, and sensorimotor cortices and significantly decreased SUV in the temporal, frontal, occipital, and parietal cortices.ConclusionThe SUV would be useful as a semiquantitative index of cerebral glucose metabolism only in healthy persons or those with mild AD.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

A case report of radionuclide bone scan findings in a patient with peroneus brevis tendonitis is presented. Peroneal tendonopathy is a common cause of lateral ankle pain. Although magnetic resonance imaging (MRI) findings have been described in the literature, we know of no other detailed report of three-phase bone scan findings, which we believe can provide an alternate means to diagnose this condition. The positive findings consist of a curvilinear band of increased activity that corresponded to the anatomic position of the peroneus brevis tendon and was detected only on the first two phases of the study.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

PurposeThe failure to cure persons with cancer is caused primarily by the development of drug resistance by overexpression of p-glycoprotein. Diverse groups of drugs have been identified, including cyclosporine A, which can reverse drug resistance by inhibiting P-glycoprotein transport. Tc-99m sestamibi is a substrate for P-glycoprotein. P-glycoprotein is normally expressed in biliary canalicular surfaces of hepatocytes and is responsible for the excretion of cationic metabolites from the liver. The aim of the current study was to evaluate the effect of cyclosporine A on the biological distribution of Tc-99m sestamibi in vivo.MethodsFive patients with alopecia and two renal transplant patients who were treated with cyclosporine A were selected for the study. All patients were examined before and at least 2 weeks after administration of cyclosporine A. Tc-99m sestamibi scintigraphy was performed by obtaining planar abdominal images at 5, 30, 60, 120, and 180 minutes after injection, and the liver–heart ratios were calculated.ResultsPlasma cyclosporine A, bilirubin levels, liver enzymes, and creatinine clearance values were obtained from all patients. In three, the plasma cyclosporine A level was increased to more than 400 pg/dl. The liver–heart ratio was increased significantly after cyclosporine A administration (P< 0.01). After cyclosporine A administration Tc-99m sestamibi excretion was delayed and the uptake in the liver was increased. The difference was 17% at 5 minutes and 38% at 180 minutes. Liver retention was greatest in patients with cyclosporine A toxicity.ConclusionsWith a limited number of patients, this study suggests that Tc-99m sestamibi excretion from the liver is mediated by P-glycoprotein, and inhibition of P-glycoprotein transport not only delays liver excretion but also increases the liver uptake of Tc-99m sestamibi. Because this observation deserves further investigation, the inhibition of P-glycoprotein function with nontoxic multidrug-resistance reversing agents may be used as an intervention to increase the tumor uptake of Tc-99m sestamibi and to increase the sensitivity of Tc-99m sestamibi tumor imaging.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

PurposeLung cancer is the leading cause of cancer deaths in the United States. Non–small-cell lung cancer (NSCLC) accounts for 75% to 85% of lung cancers. CT has been the standard anatomic study for localizing and staging NSCLC, although it is associated only with moderate accuracy. In-111 pentetreotide, a radiolabeled somatostatin analog largely used in the scintigraphic localization of neuroendocrine tumors, has been shown incidentally to identify NSCLC lesions. This observation is important in the workup for metastatic disease for neuroendocrine tumors, because presumed metastatic lesions may actually be second primary tumors of NSCLC. In-111 may also serve as a potentially useful adjunct to CT in the anatomic evaluation of NSCLC. The purpose of this study was to determine the likelihood of detecting and localizing NSCLC using In-111 pentetreotide scintigraphy.Materials and MethodsTen patients with known or possible NSCLC were examined using In-111 pentetreotide. Scans were compared with the patients’ previously performed chest radiographs and CT scans.ResultsIn-111 pentetreotide imaging correctly identified sites of tumor involvement as detected by chest CT and surgery in all 10 patients with NSCLC.ConclusionThis study demonstrates the uptake of In-111 pentetreotide by NSCLC. This important observation should be considered in the workup for metastatic disease of neuroendocrine tumors with In-111 pentetreotide, because NSCLC can be a source of false-positive findings. In-111 pentetreotide imaging may also serve as a potentially useful adjunct to CT for identifying obscured or equivocal lesions and as an aid in localizing tissue for biopsy.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

PurposeTo compare the utility of Tc-99m MIBI SPECT and Tl-201 chloride SPECT for presurgical assessment of lung cancer mediastinal lymph node metastases.MethodsForty-one patients with non–small-cell lung cancer underwent dual-isotope imaging with Tl-201 chloride and Tc-99m MIBI and were evaluated for mediastinal lymph node involvement.ResultsThe sensitivity rates of early and delayed Tc-99m MIBI SPECT and of early and delayed Tl-201 chloride SPECT for detecting mediastinal nodal metastases were 69%, 69%, 92%, and 92%, respectively. The corresponding specificity rates were 96%, 96%, 93%, and 96%.ConclusionTl-201 chloride SPECT is superior to Tc-99m MIBI SPECT when used to detect mediastinal lymph node metastases in patients with non–small-cell lung cancer.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

PurposeWhole-body, regional planar, and SPECT imaging using the In-111–labeled monoclonal antibody capromab pendetide (In-111 MAb; ProstaScint) has been shown to increase the detection of early disease spread in patients with prostate cancer. However, recognition of metastatic tumor sites can be difficult, especially if the involved nodes are near blood vessels. We have developed an alternate approach to the identification of metastatic sites that is based on a single simultaneous In-111 MAb and Tc-99m RBC SPECT acquisition of the pelvis and abdomen on day 5 after injection. We have also developed software that dynamically subtracts the Tc-99m RBC data set (vascular component) from the In-111 MAb data set (prostate and lymph node component), which allows for easier identification of metastatic sites.MethodsWe evaluated the effectiveness of ProstaScint for staging 145 patients with prostate cancer, 19 newly diagnosed and 126 with recurrence, using these two modifications.ResultsWith clinical follow-up in 13 of 19 (68%) patients with primary disease, 10 of 13 (78%) had organ-confined disease. With follow-up in 64 of 126 (51%) patients with possible recurrent disease, 49 of 64 (77%) were found to have prostatic fossa activity only. Disease stage was deemed more advanced in 3 of 13 (22%) patients with primary cancer and in 13 of 64 (20%) of those with recurrent disease based on ProstaScint findings when all other imaging tests were inconclusive. Six patients with recurrent disease had negative results of their scans. In the 16 patients with more advanced disease, 3 of 59 lesions (5%) were documented as false positive, and there were no reported cases of false-negative findings.ConclusionsUsing both the dual-isotope procedure and the subtraction analysis software with the ProstaScint examination provides additional information for staging primary and possibly recurrent prostate cancer compared with standard imaging techniques.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The diagnosis of intestinal perforation in children is difficult. Computed tomography has been a useful investigative modality. A case of duodenal perforation is presented in which radionuclide hepatobiliary imaging was useful.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Tl-201 and Tc-99m subtraction imaging is a well-established technique for detecting parathyroid adenomas. We report a case of a brown tumor of the upper sternum mimicking an ectopic mediastinal parathyroid adenoma on Tl-201 and Tc-99m subtraction imaging in a patient with hyperparathyroidism. This brown tumor showed Tl-201 uptake but not Tc-99m uptake and thus did not subtract out in this scan.

ISSN:0363-9762    

出版商:OVID    

年代:2000

数据来源: OVID