Objective To explore the feasibility of coronary magnetic resonance angiography(CMRA) with a T2-prepared turbo field echo(T2-TFE) sequence at 3.0T MR scanner.Methods 33 objects underwent CMRA at 3.0T MR imaging unit.The CMRA was performed with a 3D T2-TFE sequence.Electrocardiographically gating combined with real-time respiratory navigator gating and tracking was used to suppress the cardiac motion and correct for respiratory-induced coronary artery motion.The original images were reconstructed with MIP and Soap Bubble software.The quality of CMRA was evaluated and the lengths of the main coronary arterial branches were measured.Results 115 of 128 coronary arteries were scored higher than 3 with the standard of image quality.The lengths of LM,LAD,LCX and RCA were(12.0?3.8) mm,(79.4?18.9) mm,(60.0?12.7) mm and(110.7?27.2) mm,respectively.Conclusion CMRA with T2-TFE sequence is feasible at 3.0T.

Objective To evaluate the reproducibility of ADC measurements at 1.5 vs 3.0 T and at 1.5 T of different scanners in liver,spleen and pancreas of healthy volunteers.Methods Abdominal DWI were performed on 33 healthy volunteers by using GE 1.5 T,Siemens 1.5 T and Philips 3.0 T MR scanners.The mean ADC values of liver,spleen,pancreatic head,body,and tail were calculated.The ADC data were analyzed by using paired-sample t tests.Results The mean ADC of liver at GE 1.5 T,Siemens 1.5T and Philips 3.0 T were (1.56 ±0.10) ×10-3,(1.67 ±0.15) ×10-3 and(1.35 ±0.12) ×10-3 mm2/s,spleen were (0.96±0.10) × 10 3,(0.98 ±0.11) ×10-3and(0.81 ±0.14) × 10-3 mm2/s,pancreatic head were (2.09 ± 0.27) × 10-3,(2.20 ± 0.21) × 10-3 and (2.05 ± 0.27) × 10-3 mm2/s,pancreatic body were (2.03 ± 0.27) × 10-3,(2.09 ± 0.30) × 10-3 and (1.76 ± 0.25) × 10-3 mm2/s,pancreatic tail were (1.88 ± 0.28) × 10-3,(1.88 ± 0.27) × 10-3 and (1.56 ± 0.27) × 10-3 mm2/s,respectively.From the aspect of different field strength MR scanners,there were significant differences in mean ADC of liver (t =11.073,P ＜0.01 in GE 1.5 T vs Philips 3.0 T; t =12.795,P ＜0.01 in Siemens 1.5 T vs Philips 3.0 T),spleen (t =4.143,P ＜ 0.01 in GE 1.5 T vs Philips 3.0 T; t =5.376,P ＜ 0.01 in Siemens 1.5 T vs Philips 3.0 T),pancreatic body (t =4.677,P ＜ 0.01 in GE 1.5 T vs Philips 3.0 T; t =5.174,P ＜0.01 in Siemens 1.5 T vs Philips 3.0 T) and tail (t =5.356,P ＜0.01 in GE 1.5 T vs Philips 3.0 T; t =4.648,P ＜0.01 in Siemens 1.5 T vs Philips 3.0 T),but there were no significant differences in mean ADC of pancreatic head (t =0.340,P ＞ 0.05 in GE 1.5 T vs Philips 3.0 T; t =1.349,P ＞ 0.05 in Siemens 1.5 T vs Philips3.0 T).From the aspect of different 1.5 T MR scanners,there were significant differences in mean ADC of liver (t =-4.563,P ＜ 0.01),but there were no significant differences in mean ADC of spleen (t =-0.732,P ＞ 0.05),pancreatic head (t =-0.879,P ＞ 0.05),body (t =-1.020,P ＞0.05) and tail (t =0.054,P ＞ 0.05).Conclusion Between 1.5 T and 3.0 T MR scanners,there were significant differences in mean ADC of liver,spleen,pancreatic body and tail,but there were no significant differences in mean ADC of pancreatic head.At different 1.5 T MR scanners,there were significant differences in mean ADC of liver,but there were no significant differences in mean ADC of spleen,pancreatic head,body and tail.

Objective To investigate CT characteristics of ganglioneuroma.Methods CT findings in 12 patients with ganglioneuroma proved histopathologically were retrospectively analyzed.Results The lesions localized in the adrenal gland in 8,the retroperitoneum in 3,the posterior mediastinum in 1.eleven lesions appeared as homogeneous hypo-or isodense oval masses with well delineated margins and 1 was cysto-solid on plain CT scans.The calcifications were seen inside one tumor.On enhanced CT scans,the lesions were mild enhancement in 4,moderate enhancement in 3,significant enhancement in 3 and no enhancement in 2.Mild delayed enhancement in 5 cases,moderate delayed enhancement in 4 cases and no delayed enhancement in 3 cases were showed.Conclusion Typical ganglioneuroma shows low intensity,mild or moderate enhancement and delayed enhancement.

Objective:To explore the incidence and occurrence time of gallstone disease after bariatric surgery.Methods:Retrospectively analyzed the clinical data of 187 patients with morbid obesity who underwent bariatric surgery in the Department of General Surgery, Beijing Friendship Hospital, Capital Medical University from Dec. 2017 to Aug. 2019. All patients did not receive prophylactic ursodeoxycholic acid. All patients were underwent abdominal ultrasound and MRI examination preoperatively, and at least one abdominal ultrasound, MRI examination postoperatively. The incidence and occurrence time of gallstones and biliary sludge in patients with different bariatric surgery were analyzed respectively. Measurement data conforming to the normal distribution were described as mean ± standard deviation ( Mean± SD). Measurement data consistent with skewed distribution were described as median (lower quartile, upper quartile). Counting data were described as a percentage (%). Kruskal-Wallis test was used for comparison among groups, and then Bonferroni correction was used for pairwise comparison. Results:The follow-up time was up to Dec. 31, 2020, with a median follow-up time of 27.0 (22.0, 31.0) months. Thirty-four patients (18.2%, 34/187) developed gallstones after bariatric surgery. Individually, it was 18.0%(30/167) in LSG group, 22.2%(2/9) in LRYGB group, 11.1%(1/9) in LOAGB group and 50.0%(1/2) in LOAGB revisional surgery group. Eighteen patients (9.6%, 18/187) were found biliary sludge formation, among which 8.4% (14/167), 22.2% (2/9), and 22.2% (2/9) underwent LSG, LRYGB, and LOAGB, respectively. The rates of weight loss and BMI loss in patients with postoperative gallstone-formation were 21.4 (18.7, 23.6)% and 21.4 (18.6, 23.5) %, respectively. Three patients (1.6%, 3/187) had newly developed symptomatic gallstones, and all of them underwent LSG. The mean occurrence time for biliary sludge and gallstone was 85.5 (28.8, 98.8) and 103.5 (93.0, 179.3) days, respectively. Statistical difference in occurrence time was only found between postoperative gallstone and biliary sludge formation ( P=0.009). Conclusion:Without drug intervention, the incidence of gallstone after bariatric surgery was about 18.2% (34/187), which requires close clinical attention. Abdominal ultrasonography and the T2WI sequence of upper abdominal MRI can help to diagnose gallstone and monitor its changes.

Objective To investigate magnetic resonance imaging(MRI) characteristics of autoimmune pancreatitis(AIP) in middle-aged and elderly patients. Methods MRI were performed in 17 middle-aged and elderly patients with AlP proved histopathologically or clinically. All clinical and MRI data were reviewed. Results Of 17 cases, MRI showed diffuse enlargement of the pancreas in 13 cases, and focal lesions in 4 cases. Swelled pancreas was hypointense on T1-weighted images, mildly hyperintense on T2-weighted images, decreased enhancement on artery phase of dynamic imaging, and moderate enhancement on delayed phase images. Capsule-like enhanced rim was found around swelled pancreas in 13 patients. Stricture of distal common bile duct was present in 15 patients, and diffuse irregular narrowing of the main pancreatic duct was showed in 5 cases. The mean apparent diffusion coefficient(ADC) value of AIP was 1.64×10~(-3) mm~2/s in 13 cases. Conclusions AIP occurs more often in middle-aged and elderly people. AIP shows some characterized MRI findings including swelled pancreas looking like banana or sausage, delayed enhanced capsule-like rim around the lesion and diffuse irregular narrowing of pancreatic duct. MRI will play an important role not only in the diagnosis of AIP, but also in evaluating curative effect of AIP.

Objective To investigate the role of DWI in differentiating autoimmune pancreatitis ( AIP) from pancreatic cancer ( PC) , and in the therapeutic effect evaluation of AIP.Methods DWI data of 26 cases with AIP , 29 cases with PC and 30 cases with normal pancreas ( NP ) were analyzed retrospectively.The distribution type and signal feature of lesions in cases with AIP or PC were evaluated by Chi-squared test.ADC values were measured and compared among 3 groups by Kruskal-Wallis test.ADC values of AIP and PC were analyzed by using ROC curve to determine the optimal threshold and diagnostic efficiency.ADC values were compared in AIP ( n=15 ) before and after steroid therapy by paired t test.Results Diffuse lesions were detected in 21 cases with AIP and 3 cases with PC, while focal lesions in 5 cases with AIP and 26 cases with PC (χ2 =27.64, P<0.01).On DWI, most of AIP (n=19) and PC (n=24) showed hyper-intense signal, while a few of AIP (n=7) and PC (n =5) showed iso-intense signal (χ2 =0.75, P>0.05).The median ADC values of AIP, PC and NP were 1.15 ×10 -3,1.35 × 10 -3 ,1.59 ×10-3 mm2/s, respectively; and the difference was statistically significant ( H=45.60, P <0.01).ROC analysis yielded an optimal ADC cutoff value of 1.255 ×10 -3 mm2/s (80.8% sensitivity, 79.3%specificity and 0.871 area under curve for the diagnosis of AIP ).ADC values of AIP ( n=15) were markedly increased from the baseline (1.10 ±0.19) ×10 -3 to (1.57 ±0.12) ×10 -3 mm2/s after steroid therapy (t=-10.14, P<0.01).Conclusions DWI may be useful for diagnosing and evaluating the effect of steroid therapy in AIP.ADC values of AIP were significantly lower than those of pancreatic cancer and normal pancreas.After steroid therapy , ADC values were markedly increased in AIP.

ObjectiveTo investigate the CT findings of thymic epithelial tumors (TETs).Methods The CT images of 133 cases with TETs confirmed pathologically were reviewed retrospectively.The TETs were reclassified according to WHO 2004 Classification System.The CT features of different histopathological types of TETs were analyzed.The frequencies of demonstrating these CT features were compared between different types using Chi-square exact test.ResultsType A(9/10,90.0％),AB(15/17,88.2％),B1 (10/13,76.9％ ),and B2( 31/46,67.4％ ) tumors were more likely to have spherical or oval shapes and smooth contours on CT.TETs with irregular or lobular contours were mostly seen in type B3 (21/30,70.0％ )and thymic carcinoma (15/17,88.2％ ).TETs with cyst and necrosis formation were common in type A(6/10,60％ ),B3 ( 19/30,63.3％ ) and thymic carcinoma ( 15/17,88.2％ ).Calcification was more frequently seen in type B2 and B3 (32/76,42.1％ ) than any other type ofTETs (8/57,14.0％ ;x2 =12.20,P ＜ 0.01 ).Type A,AB,B3 and thymic carcinoma had higher prevalence of significant enhancement (39/74,52.7％) than type B1 and B2 (8/57,13.6％;x2=22.01,P＜0.01).ConclusionAccording to WHO 2004 histologic classification system,different types of TET have corresponding CT features.CT has showed the potentiality in differentiating histological subtypes of TETs.

ncreatic enlargement, MRI is comparable to CT.

Aluminum salts are the most popular adjuvants applied in human vaccines currently. However,they can′t achieve satisfying results in the development of novel vaccines because of the cellular immune responses induced by them are weak and their adjuvant activities for some novel vaccines are poor, especially in vaccination against peptide antigens with small molecular weight. cGAMP (cyclic guanosine monophosphate-adenosine monophosphate) has recently been known as a mammalian second messenger, which plays an important role in the innate immune signaling pathway and is capable of boosting the immuno-genicity of vaccines,activating antigen-presenting cells and enhancing specific T cell responses. cGAMP is expected to become a new generation of vaccine adjuvants against infectious diseases and cancer. In this re-view,we summarize the application and current situation of vaccine adjuvants, describe the discovery of cGAMP and its mechanism as a vaccine adjuvant,and focus on the advances in using cGAMP in the fields of vaccination against infectious diseases, intradermal immunization and tumor immunotherapy. Finally, it is also pointed out that cGAMP,as a novel vaccine adjuvant,will have a broad prospect of application in areas such as anti-tumor,anti-virus,anti-inflammatory and vaccines.

Objective To detect the cross-talk RF signal interference of three MRI scanners,in order to deepen the understanding of cross-talk RF signal interference.Methods Three different GE magnetic resonance imaging scanners (GE 1.5T HDi,installation time:2012;GE 3.0T HD,installation time:2006;GE 3.0T 750W,installation time:2016) were tested.The axial T1-weighted sequence was used to scan ACR phantom.Slice gaps with 5.0 mm,1.0 mm,0.5 mm and 0 were performed,respectively.SNR values were also recorded.Based on the results,the percentage change charts of SNR with slice gaps were made.Test standard was set as SNR decreased less than 20 ％ when the slice gap reduced from 5 mm to 0.Results When slice gap was reduced from 5 mm to 0,SNRs for three scanners decreased by 18.16 ％,23.57％ and 10.75％,respectively.Both the results of cross-talk obtained with GE 1.5T HDi and GE 3.0T 750W scanner met the test standard,while the result obtained with GE 3.0T HD (used for more than 10 years) was below the standard.Conclusion The cross-talk RF signal interference still exists for three MRI scanners.The test result of the scanner used for the longest time is unqualified.The quality control test of cross-talk should be done in the daily work.