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To study the changes of cerebral glucose metabolism (CGM) during the phase of return of spontaneous circulation (ROSC) after cardiac arrest (CA), we used 18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) to measure the CGM changes in six beagle canine models. After the baseline FDG-PET/CT was recorded, ventricular fibrillation (VF) was induced for 6 min, followed by close-chest cardiopulmonary resuscitation (CPR) in conjunction with intravenous (IV) administration of epinephrine and external defibrillator shocks until ROSC was achieved, within 30 min. The FDG was recorded prior to intravenous administration at 0 h (baseline), and at 4, 24, and 48 h after CA with ROSC. We evaluated the expression of two key control factors in canine CGM, hexokinase I (HXK I) and HXK II, by immunohistochemistry at the four above mentioned time points. Electrically induced VF of 6 min duration was successfully induced in the dogs. Resuscitation was then performed to maintain blood pressure stability. Serial FDG-PET/CT scans found that the CGM decreased at 4 h after ROSC and remained lower than the baseline even at 48 h. The expression of HXK I and II levels were consistent with the changes in CGM. These data from our present work showed that FDG-PET/CT imaging can be used to detect decreased CGM during CA and was consistent with the results of CMRgl. Furthermore, there were also concomitant changes in the expression of HXK I and HXK II. The decrease in CGM may be an early sign of hyperacute global cerebral ischemia. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to compare the diagnostic value of (18)F-FDG PET/CT with contrast CT for regional lymph node metastasis of colorectal cancer., Methods: Imaging results of 40 patients with colorectal cancer were retrospectively reviewed, and all the patients underwent both abdomen contrast CT and (18)F-FDG PET/CT imaging. Final diagnosis was made by histopathology., Results: 20 colorectal cancer patients were verified with lymph node metastasis while the other 20 patients were absent. Finally, (18)F-FDG PET/CT produced 4 false-positive patients and 3 false-negative patients. (18)F-FDG PET/CT displayed sensitivity 85.0% (17/20), specificity 80.0% (16/20), positive predictive value 81.0% (17/21), negative predictive value 84.2% (16/19) and accuracy 82.5% (33/40) in the diagnosis of lymph node metastasis. Contrast CT produced 5 false-positive patients and 8 false-negative patients. Contrast CT had the sensitivity 60.0% (12/20), specificity 75.0% (15/20) , positive predictive value 70.6% (12/17), negative predictive value 65.2% (15/23) and accuracy 67.5% (27/40). Sensitivity and specificity of PET/CT was better than of contrast CT, but no statistically significant difference between PET/CT and contrast CT (P = 0.478, P = 0.893; P = 0.344. Fisher's exact test and McNemar test)., Conclusion: Sensitivity and specificity of PET/CT was better than of contrast CT, but no statistically significant difference. Clinical works also need to select the appropriate inspection methods based on the patient's situation.

Objective: To evaluate the diagnostic values of (18)F-sodium fluoride ((18)F-NaF) positron emission tomography/computed tomography (PET/CT) imaging in the detection of bone metastases of lung cancer., Methods: A total of 107 lung cancer patients were diagnosed by histopathology and undergone (18)F-NaF PET-CT imaging., Results: Among them, the histopathologically diagnosed tumors included adenocarcinoma (n = 47), squamous cell carcinoma (n = 19), small cell lung cancer (n = 4) and other malignant types (n = 34). Bone metastases occurred in adenocarcinoma (n = 19) and squamous cell carcinoma (n = 4).(18)F-NaF PET/CT imaging had a high sensitivity of 100% in the diagnosis of bone metastases with malignant lung tumors. And its specificity was 98.7%, accuracy 99% and positive predictive value 97.0%., Conclusion: (18)F-NaF PET-CT imaging can detect the bone metastases of lung cancer preoperatively with a high level of sensitivity and accuracy.