Objective To investigate the application value of multi-slice CT enterography (MSCTE)in diagnosing intestinal tuberculosis (ITB)and Crohn’s disease (CD).Methods MSCTE findings were retrospectively analyzed in 25 patients with ITB and in other 25 patients with CD diagnosed through endoscopy,pathologic examination and clinical follow-up.Statistical analysis was performed to find out the difference in CT findings between the ITB and CD.Results 25 patients with CD included the involved ileum in 23,involved duode-num and jejunum in 8,multiple segmental lesions in 20,asymmetrically thickened intestinal wall in 20,hierarchical reinforcement in 1 9,mesenteric vascular hyperplasia in 20,fibrofatty hyperplasia in 18,peritoneal abscess or fistula in 8,anal fistula in 1,and pseu-do-diverticulum formation in the intestinal wall on the opposite side of the mesentery in 2.Meanwhile,the other 25 patients with ITB included the involved terminal ileum in 25,symmetrically thickened intestinal wall in 23,annular enhancement of lymph nodes in 11,thickened peritoneum and omentum together with distinct enhancement,or intestinal adhesion,or ascites appeared in 15.The CD was more likely to represent multiple segmental lesions,asymmetrically thickened intestinal wall,hierarchical reinforcement,mesenteric vascular hyperplasia,fibrofatty hyperplasia,and peritoneal abscess or fistula formation (P <0.05).Meanwhile,the ITB was more likely to represent the lesion only in ileum,symmetrically thickened intestinal wall,and annular enhancement of lymph nodes (P <0.05).Conclusion MSCTE shows promising clinical application in diagnosis and differential diagnosis of CD and ITB.

Objective To explore CT manifestion of multiple primary lung cancer (MPLC)and to improve the recognization of MPLC.Methods The CT manifestions of 12 cases with MPLC proved by pathology were retrospectively reviewed.Results All the 12 cases were double primary lung cancer.There were 24 lesions with 21 peripheral and 3 central,the average diameter was (2.2 ± 0.6)cm.Lesions located in contralateral lobes were in 2 patients,and located in ipsilateral lobes were in 10 patients,with 3 located in the same lobe and 7 in the different lobes.There were 7 cases of adenocarcinoma-adenocarcinoma,3 cases of squamous cell carci-noma-adenocarcinoma,1 case of squamous cell carcinoma-squamous cell carcinoma and 1 case of squamous cell carcinoma-carcinoid. 1 1 cases were metachronous and 1 case was synchronous.3 lesions were lump located at hilus of the lung,21 lesions were intrapul-monary nodules,showing masses with lobulated shape,spicules of margin,vascular convergence,vacuole and pleural indentation sign.Most foci displayed moderate intensity enhancement and homogeneous density in triphase enhanced scans,the CT value of le-sions on enhanced images ranged from 20-60 HU.Conclusion MPLC are synchronous and peripheral adenocarcinoma type,all of the lesions have typical CT features of primary lung cancer.

Objective To compare the image quality of chest low dose CT (LDCT) using automatic exposure control (AEC) and constant current control (CCC) and explore a more reasonable scanning protocol. Methods Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 (A1) and 30 (A2) respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA (C1) and 50 mA (C2) respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols.The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically.Differences of radiation dose and noise among groups were determined with variance analysis and t test,image quality with Mann-Whitney test and the consistency of diagnosis with Kappa test. Results There was a significant lower DLP in AEC group than in CCC group [(82.62±40.31)vs ( 110.81±18.21) mGy·cm (F =56. 88 ,P ＜ 0. 01 )], whereas no significant difference was observed between group A2 and group A1 0. 05]. The noisy of AEC group was higher than that of CCC group both on lung window(41.50±9.58 vs 40.86±7.03) and mediastinum window (41.19±7.83 vs 40.92±9.89), but there was no significant difference( Flung =0.835, P=0.476, Fmediastinum =1.910, P=0.128).The quality score of axial image in AEC group was higher than that in CCC group (superior margin of the brachiocephalic vein level: 4.49±0.56 vs4.38±0.64,superior margin of the aortic arch: 4.86±0.23 vs 4.81±0.32,the right superior lobar bronchus Level:4.87±0.27 vs 4. 84 ± 0. 22, the right middle lobar bronchus Level: 4.90±0.25 vs 4.88±0.21) except on the right inferior pulmonary vein level(4. 92 ±0. 25 vs 4. 93 ±0. 17) and superior margin of the left diaphragmatic dome level (4. 91±0.27 vs 4.93±0.22) on lung window, but no significant differences (F=0.076-1.748, P＞0.05) were observed. A significant higher score in AEC group was observed on mediastinum window compared with CCC group on superior margin of brachiocephalic vein level (2.57±0.77 vs 2. 46 ± 0. 59, F = 8. 459, P ＜ 0. 05 ), however, the score of AEC group was lower than that of CCC group on other levels without significant differences (superior margin of the aortic arch:3.36 ±0. 63 vs 3.45 ±0. 60,the right superior lobar bronchus level: 3.94 ±0. 56 vs 3. 95 ±0. 51 ,the right middle lobar bronchus Level: 3.80 ±0. 58 vs 3. 87 ±0. 50,the right inferior pulmonary vein level: 3.72 ±0. 56 vs 3.78 ±0. 53, superior margin of the left diaphragmatic dome level: 3.58 ± 0.63 vs 3.68±0.56,F=0.083-3.380,P ＞ 0.05 ). The MPR image quality of AEC group was better than that of CCC group both on lung window and mediastinum window (Zlung =-2.258, Zmedlastinum=-1.330, P＞0.05). For all participants including the underweighted group, the normal group and the overweighted group, the image quality of A1 group was better than that of A2 group without significant differences (the underweighted group: Zlung=0.000, P=1.000, Zmedastinum= 0.000, P=1.000;the normal group: Zlung =-0.062, P=0.950, Zmediastinum =-0.746, P = 0.456; the overweighted group: Zlung = - 1.177, P = 0.239,Zmediastinum =-1.715, P=0.144) both on lung and mediastinum windows, and for the higher BMI participants, a better image quality was obtained in A1 group than in A2 group on the mediastinum window (Z = -1. 715, P = 0. 144). Conclusions The total radiation exposure dose of AEC group is significantly lower than that of CCC group, but no statistical significant differences are observed between both groups in image quality and noise level. The AEC technique is highly recommended in thoracic LDCT scan for screening program, and the SD25 ( SD value = 25) scan protocol is suggested for higher BMI population while the SD30 (SD value = 30) scan protocol for lower BMI population.