Change in brain perfusion after extracranial–intracranial bypass surgery detected using the mean transit time of computed tomography perfusion

BackgroundCerebral perfusion can be evaluated using a computed tomography (CT) scan by intravenous bolus injection of contrast media. The purpose of this study was to investigate the value of CT perfusion (CTP) in follow-up of extracranial–intracranial (EC-IC) bypass surgery.MethodsWe retrospectively reviewed pre- and postoperative CTP studies in 14 patients who received EC-IC bypass surgery because of cerebral arterial occlusion or stenosis. Brain areas showing prolongation of the mean transit time (MTT) were automatically identified and quantitatively measured.ResultsAll 14 patients showed MTT prolongation in the preoperative CTP study. In 13 patients, a reduction in brain volume with MTT prolongation was noted during postoperative CTP. These 13 patients had a patent EC-IC anastomosis, and 42 ± 21% of the brain area with MTT prolongation returned to normal MTT during CTP 7 ± 4 days (range 2–13 days) after surgery. On clinical follow up of 41 ± 16 months (range 14–60 months), no stroke or transient ischemic attack was noted after bypass surgery in these 13 patients. The brain volume with MTT prolongation did not decrease in just one patient whose EC-IC anastomosis was not patent, and the patient suffered a minor stroke during surgery.ConclusionQuantitative results for the brain area with MTT prolongation were positively correlated with improvement in brain perfusion shown on MTT, EC-IC bypass patency, and patient outcome.     

E-cadherin蛋白在前列腺癌组织中的表达及临床意义

目的　探讨上皮细胞钙粘素 (E cadherin ,E Cad)在前列腺癌组织中的表达及其临床意义。方法　应用免疫组织化学 (SP)方法测定 42例前列腺癌及 3例正常和 7例良性前列腺增生组织中E Cad蛋白的表达。结果　 42例前列腺癌组织中 2 1例E Cad蛋白表达阳性 ( 5 0 %)。随肿瘤细胞病理分级、临床分期程度的增高 ,癌细胞表达E Cad蛋白阳性率降低 ,高、中分化组 2 2例前列腺癌中 19例E Cad蛋白表达阳性( 86%) ,与低分化组 2 0例中 2例 ( 10 %)阳性表达 ;A +B期和C +D期前列腺癌组织中的阳性表达率分别为 65 5 %( 19/ 2 9)和 15 3 %( 2 / 13 ) ,各组间比较有显著性差异 ( χ2 =2 4 43 ,P <0 0 0 5 ;χ2 =9 0 3 ,P <0 0 0 5 )。而正常和良性前列腺增生组E Cad蛋白均呈阳性免疫反应。结论　E Cad蛋白异常表达在前列腺癌的恶性进展中起重要作用 ,检测E Cad蛋白的表达有利于判断病期及预后。     

杭州地区军队离休老干部前列腺症状调查

目的　了解杭州地区军队离休老干部前列腺增生 (BPH)的症状情况。方法　采用国际前列腺症状评分 (IPSS)及生活质量评估 (QOL)的方法对 389名 6 5岁以上的军队离休老干部进行问卷调查。结果　BPH的患病率为 5 4 .3% ,按年龄分组的患病率 6 5 ,70 ,75 ,≥ 80岁者分别为 32 .0 % ,4 8.4 % ,5 2 .7%和 6 7.0 %。IPSS及QOL的平均分分别为 12 .5 9和 2 .39。BPH症状轻、中、重度的比例分别是 4 5 .8% ,36 .8%和 17.5 %。结论　前列腺增生症患病率较高 ,是离休老干部的常见病之一。随年龄增大 ,BPH的发病有增长趋势     

18F]FBAU 3',5'-dibenzoate, a lipophilic prodrug, enhances brain uptake of the cell proliferation tracer [18F]FBAU

INTRODUCTION: 1-(2-deoxy-2-[(18)F]fluoro-beta-D-arabinofuranosyl)-5-bromouracil ([(18)F]FBAU) is a cell proliferation tracer. However, it does not pass readily through the blood-brain barrier. We synthesized a lipophilic prodrug of [(18)F]FBAU that was intended to enhance brain uptake of [(18)F]FBAU to improve the imaging of brain cell proliferation. METHODS: [(18)F]FBAU was synthesized according to the methods described by Alauddin [J Med Chem 39 (1996) 2835-2843]. The prodrug, 1-(2-deoxy-3,5-O-dibenzoyl-2-[(18)F]fluoro-beta-D-arabinofuranosyl)-5-bromouracil ([(18)F]FBAU 3',5'-dibenzoate), was purified from an intermediate of [(18)F]FBAU. Their lipophilicity was determined by performing octanol/water partition coefficient (log P) measurements. In vitro metabolic fates of the prodrug were examined in rat and mouse plasma and brain homogenates. Brain uptake was determined following iv injection of the radiotracers by killing animals at various time points and dissecting and counting the radioactivity accumulation in the various tissues. RESULTS: Values of log P for [(18)F]FBAU 3',5'-dibenzoate and [(18)F]FBAU were 3.95 and -0.35, respectively. In rat plasma, the prodrug was gradually hydrolyzed to [(18)F]FBAU. Thirty minutes after mixing [(18)F]FBAU 3',5'-dibenzoate in the plasma, 25% of the prodrug had been hydrolyzed. The hydrolysis went more slowly in brain homogenates. At 15 min post injection, relative to animals injected with [(18)F]FBAU, brain uptake of radioactivity in animals injected with [(18)F]FBAU 3',5'-dibenzoate was increased by 150% (P=.005) and 78% (P=.037) in rats and mice, respectively. At 60 min post injection, the radioactive contents extracted from the brain were mostly [(18)F]FBAU. CONCLUSION: The synthesized novel prodrug [(18)F]FBAU 3',5'-dibenzoate has enhanced brain uptake in rodents, suggesting it may be useful as an imaging agent for tracing brain cell proliferation.     

18F-FDG PET or PET/CT for detecting extrahepatic metastases or recurrent hepatocellular carcinoma: a systematic review and meta-analysis

Aim

Positron emission tomography (PET) using F18-flurodeoxy-glucose (FDG) has been widely used for reflecting cellular metabolism. However, the feasibility of FDG PET in the diagnosis of hepatocellular carcinoma (HCC) is limited. The aim of the study was to assess the ability of FDG PET (PET/CT) in the detection of extrahepatic metastases or recurrent HCC.

Materials and methods

We conducted MEDLINE, EMBASE and COCHRANE searches (last update, April 2011). Eight eligible articles were identified evaluating F18-FDG PET (PET/CT) in extrahepatic metastases or recurrent HCC. Two authors independently evaluated the methodological quality of each study. We estimated pooled sensitivities, specificities, summary receiver-operating-characteristic (SROC) curves, and summary likelihood ratios.

Results

Eight eligible studies were enrolled in this study. The pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FDG PET (PET/CT) in the detection of metastatic HCC were 76.6%, 98.0%, 14.68, and 0.28, respectively. The pooled estimates of sensitivity, specificity, LR+ and LR− of FDG PET (PET/CT) in the detection of recurrent HCC were 81.7%, 88.9%, 4.72, and 0.19, respectively.

Conclusion

Based on the results of this systematic review, F-18 FDG PET (PET/CT) was useful in ruling in extrahepatic metastases of HCC and valuable for ruling out the recurrent HCC.     

Pancreatic transplant imaging

Forty-four clinical episodes of suspected (pancreas) transplant rejection in 17 pancreatic transplantation patients were reviewed retrospectively. The clinical impression of acute graft rejection, chronic rejection, or nonrejection in each episode was correlated with the results of 19 nuclear medicine, 12 ultrasound (US), and 44 magnetic resonance (MR) imaging studies. US was found to be a moderately sensitive (82%) method of detecting graft rejection. US also was effective in identifying intra- and peripancreatic fluid accumulations. Nuclear medicine imaging was also a sensitive technique (86%) and the only modality that provided physiologic information regarding graft perfusion. MR imaging allowed correct prediction of the presence or absence of graft rejection in 39 of 44 cases (sensitivity, 100%; specificity, 76%) and was an effective means of detecting pathologic fluid collections. Nuclear medicine, US, and MR imaging are all believed to be sensitive methods of detecting graft rejection and are complementary adjuncts to the clinical evaluation of pancreatic transplants.     

GMP production of [<Superscript>18</Superscript>F]FDOPA and issues concerning its quality analyses as in USP “Fluorodopa F 18 Injection”

Introduction  

Lately, 6-[¹⁸F]fluoro-l-DOPA (FDOPA) has found increase in its clinical demand for whole-body positron emission tomography (PET) scans, and two key issues in fulfilling this demand are the difficulties in producing FDOPA under the recently imposed PET drug good manufacturing practice (GMP) regulations and in providing it in the quality meeting the terms of major compendia. This paper describes the approaches for the GMP production of FDOPA and for the product testing to meet the standard of United States Pharmacopeia (USP) “Fluorodopa F 18 Injection.”     

Thyroid incidentalomas on fluorine-18-fluorodeoxyglucose positron emission tomography-computed tomography: incidence, malignancy risk, and comparison of standardized uptake values

Introduction

To determine the incidence of fluorine-18-fluorodeoxyglucose (FDG) avid thyroid incidentalomas detected on positron emission tomography (PET) with integrated computed tomography (CT), and correlate the FDG–PET-CT findings to cytology.

Methods

A total of 942 FDG–PET-CT reports were retrospectively reviewed. Patients with FDG-avid thyroid incidentalomas were further reviewed for correlative cytology.

Results

The incidence of FDG-avid thyroid incidentalomas is 2.2%. Thyroid malignancies were identified in 3 of 6 patients who underwent cytologic correlation, with a positive predictive value of 50% (95% confidence interval, 14%-86%). The mean maximum standardized uptake values of benign and malignant FDG-avid thyroid incidentalomas were 5.6 and 6.6, respectively.

Conclusion

A FDG-avid thyroid incidentaloma may predict underlying malignancy. Cytologic assessment should be considered for FDG-avid thyroid incidentalomas.     

Clinically unrecognized pulmonary aspiration during gastrointestinal endoscopy with sedation: a potential pitfall interfering the performance of 18F-FDG PET for cancer screening

PurposeWe found several cases with unexpected pulmonary abnormalities on the ¹⁸F-FDG PET scan after the gastrointestinal endoscopy with sedation during a compact health check-up course, interfering the interpretations of ¹⁸F-FDG PET scan for cancer screening. The current studies aimed to analyze the incidence and the clinical relevance of this pulmonary finding.Materials and methodsFrom June to December 2009, 127 subjects undergoing the sequential gastrointestinal endoscopy with sedation and ¹⁸F-FDG PET scan within 48 h as part of routine health check-up were retrospectively enrolled in this study. The incidence of abnormal pulmonary findings and their SUV_max of FDG were calculated and correlated with the clinical manifestations.ResultsFive subjects had abnormal ¹⁸F-FDG PET findings but pulmonary symptoms were only found in 2. The SUV_max did not seem to reflect the severity of pulmonary symptoms or the need of intervention. Although the incidence of unrecognized pulmonary aspiration featuring inflammation detected by the ¹⁸F-FDG PET scan was high (3.94%, 5/127), the incidence of events needed intervention remained low (0.79%, 1/127), similar to those previously reported literatures.ConclusionsAlthough higher incidence of pulmonary aspiration in this study, it probably reflects the better sensitivity of ¹⁸F-FDG PET for inflammation. The low incidence of clinical events needed intervention may still reflect the safety of sedation used for gastrointestinal endoscopy. Proper arrangement of the sequential examinations if subjects need both gastrointestinal endoscopy with sedation and ¹⁸F-FDG PET is important to reduce the interference degrading the performance of ¹⁸F-FDG PET in cancer screening, diagnosis or staging.     

A unique finding on gallium-67 scintigraphy: widespread fatal skin manifestations of Pseudomonas sepsis

We report a case of a 25-year-old woman presented with neutropenic fever after chemotherapy for the relapse of acute biphenotypic leukemia. Gallium-67 scintigraphy for the detection of infectious foci demonstrated a unique pattern of numerous foci with intense and varying-sized radioactivity spreading throughout the body. The subsequent skin biopsy and culture proved Pseudomonas infection. Therefore, this unique image, in combination with clinical information, was compatible with cutaneous manifestations of Pseudomonas sepsis. Eventually, the patient died of uncontrolled systemic infection despite the aggressive antibiotic treatment. This case reminded clinicians and nuclear medicine physicians to notice the potentially fatal finding on gallium-67 scan.