Objective To demonstrate the feasibility of DTI in human calf with body phased-array coil and surface coil of spine as receiving coil on 3 T system, and to optimize the parameters of sequence, including slice thickness and b-value. Methods Fifteen healthy volunteers were recruited in this study and randomly divided into three groups. The DTI sequence for head was performed on calf in the first group (5 cases), and the sequence parameters were optimized based on the deficits of the raw and the post-processed DTI images. Then, different slice thickness were applied in the senond group (5 eases) to optimize the slice thickness, and this optimized parameter with the highest score based on quality of the post-processed DTI images was applied in the next step. Finally, different b values were applied in the last group to optimize this parameters. The b value with the highest score based on the quality of the pest-processed was the proper one. Results Three problems existed in the raw and the pest-processed images, when the DTI sequence for brain was used for the calf. First, the SNR of raw images is extremely low. Second, the muscle were unclear on the image with parts of signal lose, especially in the anterior tibialis muscle. Finally, the artifacts due to chemical shift and ghost are quite serious. The scores for muscle display quality with slice thickness of 4 mm , 5 mm and 6 mm were (7.0±0. 0), (8.6±0. 9) and (9.0±0. 0) score respectively, the signal less scores were (5.0±0. 0) and ( 12. 8±2. 6) and ( 13. 8±2. 2) score respectively, and the general score were (22. 0±0. 0) and (30. 1±3.8) and (31.0±4. 1 ) score respectively. The differences of above scores were significant among different slice thickness (F-value were 21. 000 and 30. 544 and 12. 390 respectively, P <0. 05 ). The muscle displaying quality, signal loss and general scores were lowest in group with 4 mm slice thickness (q-value were 4. 896.6. 120,6. 327,7. 138,3. 863 and 4. 043, P < 0. 05 ) o The scores of muscle display quality, signal loss and general for b =400 s/mm2 were (9. 0±0. 0), ( 14. 0± 2. 2 ) and ( 33.0±2. 2 ) score respectively, which were lower than those with b = 800 s/ram2 [(7.0±0.0), (6.2±2.2), (21.8±3.4) score] and b=1000 s/mm2[(7.0±0.0), (5.0±0.0), (20.6±2.2) score] (q-value were 3.873,3.873,6.650,7.672,7. 101 and 5.917, P <0.05)o The scores of muscle displaying quality, signal loss and general for b =600 s/mm2 were (8.2±1.1 ), ( 13.0± 2. 3) and ( 30. 8±3. 8 ) score respectively, which were higher than those with b = 800 s/mm2 and b= 1000 s/nun2 (q-value were 3.873, 3.873, 5.797, 6.820, 5.326 and 5.917, P <0.05).There is no significant difference between b = 600 s/ram2 and 400 s/ram2 ( q-value were 2. 582 and 0. 852 and 1. 775, P > 0. 05 ). Conclusion Our preliminary findings indicate that it is feasible to perform DTI on human calf with 3 T MR. With body phased-array coil and surface coil of spine as receiving coil, the DTI sequence were optimized to acquire enough SNB with slice thickness of 5 mm and b-value of 400 s/mm2.

In order to help the standardized residency training of nuclear medicine residents, the standardized residency training base of nuclear medicine residents in Peking University People's Hospital, combined with forty-five nuclear medicine departments of teaching hospital, established the WeChat official account of "Standardized Residency Training of Nuclear Medicine" and submitted one teaching case per week. The appearance of the WeChat official account of "Standardized Residency Training of Nuclear Medicine" has made up for the shortcomings of insufficient teaching cases in a single training base, strengthened the training of residents' imaging diagnostic thinking, and promoted mutual learning among the bases. By writing teaching cases, instructors and residents have opened up ideas, increased knowledge, improved self-learning ability, and cultivated imaging diagnostic thinking. With the flexible and practical features of the WeChat official account, the consciousness and sustainability of residents' learning have been enhanced.

Objective:To further understand the etiological distribution of fever of unknown origin (FUO) in patients underwent 18F-fluorodeoxyglucose (FDG) PET/CT imaging, and to explore the significance of 18F-FDG PET/CT in the diagnosis of different types of diseases in FUO patients. Methods:From January 2013 to August 2019, the clinical and PET/CT image data of 466 FUO patients (194 males, 272 females, age: 3-91(52.7±20.9) years) in Peking University People′s Hospital were retrospectively analyzed. The etiological distribution of FUO patients was analyzed according to the final clinical diagnosis. PET/CT imaging manifestations were analyzed for different types of diseases in FUO patients. The role of 18F-FDG PET/CT in differential diagnosis for FUO was evaluated through clinical questionnaire. Data were analyzed by using χ2 test. Results:The common disease types in FUO patients were rheumatic and immune disease (48.7%, 227/466), infection (28.5%, 133/466) and malignant tumor (11.2%, 52/466). For PET/CT imaging, 95.5% (445/466) of the patients were positive, of which 313 (70.3%, 313/445) were found to have focal lesions, and the other 132 (29.7%, 132/445) showed only nonspecific abnormal uptake. Lesions in different types of diseases were varied in the location, morphological changes as well as FDG uptake. The results of the questionnaire showed that PET/CT imaging could benefit 95.9% (447/466) of the patients in the FUO diagnosis and treatment. PET/CT reached direct etiological diagnosis of malignant tumors more frequently than other types of diseases ( χ2 values: 14.408-25.466, all P<0.001). PET/CT helped or directly reached the etiological diagnosis of rheumatologic diseases more frequently than infection and unknown cause group( χ2 values: 7.922, 9.647, both P<0.05). Conclusion:18F-FDG PET/CT imaging has high clinical value in the diagnosis of FUO etiology and can provide multilevel diagnostic information.

Artificial conduits, including ureteral stents and catheters, are used widely as drainage tools in the urinary system. However, various bacteria in the urine and long duration of insertion can arouse the biofilm formation on the pipeline surface, which calls for effective antibacterial strategy. In this article, the mechanism of Catheter Associated Urinary Tract Infections (CAUTI) is explained from the perspective of etiology. Then, the biofilm formation conditions and the features of urine are analyzed, the antibacterial agents and approaches suitable for ureteral stents and catheters are introduced and their pros and cons are discussed respectively.
Anti-Bacterial Agents ; Catheters ; Drainage ; Humans ; Stents ; Urinary Catheterization ; instrumentation ; Urinary Tract Infections