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Objective: To explore the relationship of 18F-FDG PET/CT imaging and pulmonary function and laboratory inflammatory biomarkers in patients with idiopathic interstitial pneumonia (IIP). Methods PET/CT imaging of 20 patients with IIP (IIP group) and 20 patients without pulmonary lesions (control group) were retrospectively analyzed. The maximum standard uptake value (SUVmax) and mean SUV (SUVmean) of the whole lung were measured, and the maximum target-to-back ratio (TBRmax) and mean TBR (TBRmean) were calculated. SUV and TBR were compared between IIP group and control group, and the correlation of TBR and pulmonary function indexes and inflammatory biomarkers in IIP group were evaluated. Results SUVmax, SUVmean, TBRmax and TBRmean in IIP group were significantly higher than those in control group (all P0.05), nor between TBR and erythrocyte sedimentation rate and C-reaction protein (both P>0.05). Conclusion: The radioactive uptake increases in IIP patients, which has certain correlation with pulmonary function.
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Objective: To investigate the diagnostic value of 18F-FDG PET/CT combined with MR cholangiopancreatography (MRCP) multimodal imaging in diagnosis of malignant and benign obstructive jaundice. Methods Totally 57 biliary obstruction patients were enrolled and divided into malignant obstruction group (n=31) and benign obstruction group (n=26). The diagnostic efficacy of 18F-FDG PET/CT, MRCP and multimodal imaging of obstructive jaundice were analyzed and compared. Results In malignant obstruction group, moderate to severe biliary expansion accounted for 41.94% (13/31), while in the benign obstruction group, the rate was 3.85% (1/26), and the difference between the two groups was statistically significant (P=0.047). The maximum standard uptake value (SUVmax) of malignant obstruction group (10.54±6.69) was significantly higher than that of the benign obstruction group (3.78±1.68; P0.05), while compared with MRCP, the differences in sensitivity and accuracy were statistically significant (P=0.002, 0.002), the difference in specificity was not statistically significant (P=0.463). Compared with final results, the Kappa coefficients of multimodality imaging, 18F-FDG PET/CT and MRCP were 0.858, 0.752 and 0.375, respectively. Conclusion 18F-FDG PET/CT combined with MRCP multimodal imaging is helpful to improvement of the diagnostic accuracy of obstructive jaundice, which has important guiding significance for diagnosis and clinical treatment decision-making.
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Objective: To assess the changes of glucose metabolism in hypertrophic cardiomyopathy (HCM) patients with 18F-FDG PET in fasting and glucose-loading states. Methods Totally 36 patients with HCM underwent cardiac MRI (CMRI) and twice 18F-FDG PET, once in fasting state and once during glucose load state. Semiquantified assessment of metabolism score to PET images was analyzed. According to the delay enhancement (DE) on CMRI, HCM patients were divided into DE-positive group (n=24) and DE-negative group (n=12). Then the difference of semiquantified scores was compared. Results In fasting state, patients in DE-positive group had lower summed metabolism scores than those in DE-negative group (23.73±7.02 vs 36.24±14.18, P=0.015), while there was no significant difference in glucose-loading state (6.25±10.63 vs 4.38±7.41, P=0.099). Totally 11 patients had 42 myocardial segments which were normal or with improved uptake in fasting state, but defected or sparse during glucose load state. Compared with other 25 patients, these 11 patients had greater left ventricular wall thickness and greater left ventricular posterior wall thickness, more segments with DE and lower left ventricular ejection fraction (all P<0.05). Conclusion 18F-FDG PET myocardial glucose metabolism imaging in HCM patients in fasting state and during glucose load state shows obvious heterogeneity. Combined with CMRI, it may be used as an indicator of risk stratification in patients with HCM.
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Objective: To establish mathematical prediction models based on PET metabolic parameters, and to explore their value for differentiating benign and malignant solitary pulmonary lesions. Methods Data of 135 patients with solitary pulmonary lesions who underwent 18F-FDG PET/CT scan were retrospectively analyzed. PET metabolic parameters of the lesions were obtained, including metabolic tumor volume (MTV), maximum standardized uptake value (SUVmax), peak standardized uptake value (SUVpeak), mean standardized uptake value (SUVmean) and total lesion glycolysis of standardized uptake value (SUVtlg), as well as parameters of standardized uptake normalized to lean body mass (SUL), including SULmax, SULpeak, SULmean and SULtlg. The parameters above were used to establish support vector machine (SVM) models, which were selected according to the Akaike's information criterion (AIC). The diagnostic performances of the models were assessed with ROC curves. The permutation test was used for internal validation. Results: Two sets of optimization models were obtained and recorded as Mgroup A (include MTV, SUVpeak and SUVtlg) and Mgroup B (include MTV, SUVpeak and SULtlg). AUC of Mgroup A model was 0.865 (P=0.021), with the sensitivity of 82.72%, specificity of 83.33% and diagnostic accuracy of 82.96%, of Mgroup B model was 0.863 (P=0.030), with the sensitivity of 82.72%, specificity of 83.33% and diagnostic accuracy of 82.96%, respectively. There was no statistically significant difference of AUC between the two models (P=0.294). Both models were reliable evaluated with the permutation test. Conclusion: SVM models based on PET metabolic parameters can be used for differential diagnosis of benign and malignant solitary pulmonary lesions, whereas metabolic parameters corrected by lean body mass bring no remarkable improvement on diagnostic efficacy.
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Objective: To investigate the impact of saline flush for syringe after 18F-FDG injection on the residual dose of 18F-FDG and the standardized uptake value (SUV) of liver during PET/CT examination. Methods: A total of 50 patients who underwent PET/CT examination were enrolled and divided into control group (n=25) and experimental group (n=25) according to different injection methods. Device system of the vein passage was established with 23 gauge scalp needle. In control group, the intravenous line was directly flushed with 5 ml physiological saline after 18F-FDG injection, while in experimental group, firstly the intravenous line was flushed with 1 ml saline, then the syringe was flushed with 2 ml saline, finally the intravenous line was flushed again with the residual 2 ml saline. The residual dose of 18F-FDG and SUVmean and SUVmax of liver were compared between the two groups. Results: The total residual dose ([0.22±0.08]mCi), syringe residual dose ([0.19±0.07]mCi) and intravenous channel residual dose ([0.03±0.02]mCi) in the experimental group were all lower than those in control group (all P0.05). Conclusion: Flushing the syringe can reduce residual dose of 18F-FDG injection. A small amount of radiopharmaceuticals retention in the syringe may not affect SUV for liver, but further standardization of the operation process of 18F-FDG injection is still necessary.
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Parkinson disease (PD) is a common neurodegenerative disease. PET has special advantages in early identification, diagnosis and evaluation of PD. The main PET tracers contain 18F-FDG and dopaminergic neuron function targeting imaging tracers. The research status and progresses of 18F-FDG PET brain imaging and dopaminergic neuron function targeting imaging on evaluation of PD were reviewed in this article.
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Objective To evaluate the clinical value of 18FDG PET/CT in the diagnosis of lymph node metastasis and evaluation of node staging for esophageal carcinoma. Methods A prospective study was performed to access whether 18F FDG PET/CT can improve the diagnostic accuracy in lymph node metastasis for patients with esophageal carcinoma, 30 patients underwent esophagectomy with extensive dissection of lymph nodes. PET/CT findings were compared with that of CT. Results The pathological examination confirmed metastasis in 22 patients and 49 out of 243 excised lymph nodes. In PET/CT analysis, the sensitivity in the detection of lymph node metastasis was 93.9%, specificity was 91.2%, with a diagnostic accuracy of 91.8%. The positive and negative predictive value was 73.0% and 98.3%, respectively. CT resulted in a sensitivity of 40.8%, specificity of 96.9%, accuracy of 85.6%, the PPV was 76.9% and NPV 86.6%, respectively. The difference of sensitivity (P
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Objective To investigate the glucose metabolism changes of cerebral ischemic area after middle cerebral artery occlusion (MCAO) in cat on 18 *"FDG-PET scans.Methods A permanent focal cerebral ischemia model of cat was established by electrocoagulating the terminal of left middle cerebral artery via a transorbital approach. 15 minutes before MCAO, 0.5 mCi 18 *"FDG were intravenous bolus injection.15 minutes, 1 h, 3 h, and 6 h after ischemia, 18 *"FDG-PET were performed and the SUV were measured. After neurological examination, the cats were killed for performing TTC stainnig.Results The SUV of ischemic area were highter than that of contralateral and control area(P
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Objective To evaluate the correlation between changes in regional cerebral glucose metabolism and reduced body mass index (BMI) in patients with mild to moderate Alzheimer's disease(AD). Methods Regional cerebral glucose metabolism in many regions of interest of 27 AD patients were measured by positron emission tomography (PET) through 18 F fluro deoxyglucose (FDG) and their correlation with low BMI was analysed. Results The analysis using simple and multiple regression correlation showed that the metabolic ratio had a positive correlation with low BMI only in anterior cingulate cortex. Conclusions Anterior cingulate cortex may preferably involve in the regulation of food intake and body weight.
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Objective To assess the val ue of 18-fluorodeoxy glucose (~18F-FDG) positron emission tomography( PE T)-CT in the detection of malignant bone metastases. Methods Thirty-five out of 332 patients, 89 lesions were detected on ~18 F-FDG PET-CT and were interpreted separately on PET, combined CT, and fused PE T-CT images. Results Of the 89 lesions detected on PET- CT images, 68 were malignant and 21 were benign lesions. PET alone identified 62 malignant lesions and 17 benign lesions. The diagnostic sensitivity, specificit y, and accuracy of PET alone for diagnosis of bone metastases were 91.2% (62/68) , 81.0% (17/21), and 88.8% (79/89), respectively. The combined CT alone identifi ed 55 malignant lesions and 16 benign lesions. The diagnostic sensitivity, s pecificity, and accuracy of combined CT alone were 80.9% (55/68), 76.2% (16/21), and 79.8% (71/89), respectively. The fused PET-CT images identified 64 maligna nt and 19 benign lesions. The diagnostic sensitivity, specificity, and accuracy of the fused PET-CT were 94.1% (64/68), 90.5% (19/21), and 93.2% (83/89), respe ctively. Conclusion In the diagnosis of bone metastases, ~18F-FDG PET-CT imaging reduces the false positive rate and increases the specificity. ~18F-FDG PET-CT imaging is helpful in the differentiation o f bone metastases from benign lesions.
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Bone scintigraphy is a very sensitive and cost-effective diagnostic method for detecting bony metastases of malignant neoplasm. However it has been reported that bone scan is less sensitive for early bony metastases, especially vertebral metastases. PET is a non-invasive clinical imaging methodology that can be used to assess such biochemical disturbance in tissue in vivo quantitatively with high resolution.We experienced two cases of small cell lung cancer with multiple bony metastases which were detected on PET imaging but not on planar bone scan. This case report suggests that FDG-PET will be a very effective diagnostic tool for bony metastases especially in clinically suspected case despite a normal planar bone scan.