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Objective: T To investigate the distribution and occurrence probability of artifact of "hot air spot" in integrated PET/MR examination, and the role of time of flight (TOF) in alleviating the artifact of "hot air spot ". Methods: The occurrence sites and probability of artifact of "hot air spot" in 105 examinees who underwent integrated whole-body PET/MR examination were retrospectively analyzed, and the occurrence of heat organ sign in integrated PET/MR without TOF technology and TOF-PET/MR images were evaluated. Results: The artifacts of "hot air spot" were distributed in sinus, trachea, gastric sinus, colon and rectum, and most commonly in trachea in the integrated PET/MR examination, and the incidence rates were 60.00%(63/105), 68.57%(72/105), 8.57%(9/105), 20.00%(21/105) and 16.19%(17/105), respectively. The SUVmax of different parts on PET/MR images without TOF technology were 4.09±2.17, 1.77±0.81,1.75±0.85,3.73±0.51 and 11.77±8.39, respectively. The SUVmean of different parts on integrated TOF-PET/MR images were 3.19±1.87, 1.38±0.70, 1.44±0.85, 2.68±0.46 and 6.78±4.19, respectively. The SUVmax and SUVmean of artifact of "hot air spot" on PET/MR images without TOF technology were higher than those on integrated TOF-PET/MR images (all P<0.01). Conclusion: The artifact of "hot air spot " mainly exists in the sinuses, trachea and digestive tract in integrated whole-body PET/MR examination. The artifact of "hot air spot" in the trachea is the most commonly happened among them. TOF technology can obviously help to reduce the "hot air spot" artifact on the integrated PET/MR examination without TOF technology, thus significantly improving the quality of the integrated PET/MR image.
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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 explore the consistency of time-of-flight (TOF) technology of PET/MRI and PET/CT for max standardized uptake value (SUVmax) of body malignant tumors.Methods A retrospective analysis of TOF-PET/CT and TOF-PET/MR imaging data about twenty patients with body malignant tumors was performed.Patients were divided into two groups (each n=10),including PET/CT first and sequentially PET/MR group and PET/MR first and sequentially PET/CT group.Bland-Altman figure was used to evaluate consistency of SUVmax of malignant lesions between TOF-PET/CT and TOF-PET/MR.Multi-way ANOVA was used to analysis effect of machine type and exam order on SUVmaxof malignant lesions in TOF-PET/CT and TOF-PET/MR.Results SUVmax of malignant lesions in TOF-PET/CT and TOF-PET/MR had good consistency in two groups (PET/CT first and sequentially PET/MR group:Mean difference was 3.06,95％CI was [-7.5,13.6];PET/MR first and sequentially PET/CT group:Mean difference was 3.0,95％CI was [-2.4,8.3]).SUVmax was not influenced by machine type (F=0.005,P=0.95),but exam order (F=46.00,P＜0.001).Conclusion PET/MR and PET/CT with TOF technology have comparative diagnostic value in SUVmaxof body malignant lesions.SUVmax of body malignant lesions increases in delay time,which is not related to machine type,but exam time.
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Objective To observe MSCT and clinical features in patients of laryngocarcinoma combined with other primary carcinomas. Methods Five patients of laryngeal cancer combined with multiple primary cancer were enrolled in the study. Three paitents had long-term smoking history more than 20 years. Three paitents had various degree of radiotherapy, chemotherapy and immunotherapy. The second primary cancer located in right upper lung lobe in 2 patients of synchronous cancer and 1 patient of metachronous cancer. The others located in soft palate, uvula and the left side of zone Ⅱ and zone Ⅳ in the neck, respectively. MSCT and clinical characteristics were analyzed. Results Five patients of multiple primary cancers included 2 patients of synchronous cancer and three patients of metachronous cancer. MSCT found the appearances of malignant tumors in various parts in all 5 patients and cervical lymph nodes metastasis in 2 patients. Conclusion The possibility of prime laryngocarcinoma combined with other primary cancers should be considered when other organ malignant tumor was detected in patients with laryngeal carcinoma, especially in patients with history of long-term smoking, radiotherapy and chemotherapy and immunotherapy. Long-term following-up of cervix and other organs should be taken for the postoperative patients of laryngocarcinoma.
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Effect of scalding on secretory function of beta-endorphin neuron in the arcuate nucleus of the rat hypothalamus was studied semiquantitatively using immunocytochemistry and image analysis. The results showed that the number of beta-endorphin neurons and area of positive products reduced significantly (P