Objective To improve the diagnostic accuracy of ovarian endometrioma and to discriminate it from other adnexal masses by analyzing its CT manifestations. Methods The CT images of 57 patients with 77 ovarian endometriomas proved by surgery and pathology were studied retrospectively.Results The cysts ranged in diameter from 2 to 14 cm with the mean size of 6.2 cm?5.1 cm. The margins of the cyst were sharp in 39 and ill defined in 38 endometriomas. Thin and thickened walls were found respectively in 40 and 37 of 77 endometriomas. Unilocular, bilocular and multilocular forms were seen respectively in 29(37.7%), 23(29.9%) and 25(32.5%) of 77 endometriomas. Gourd and sister forms were present respectively in 15 and 8 of 23 bilocular cysts, and sister loculi, outer son loculi, inner son loculi, and mixed forms in 10, 9, 1 and 5 of 25 multilocular endometriomas. The density of the cyst fluid varied from 11～65 HU with the mean of 28.5 HU. New hemorrhage inside cyst was found in 6 cysts. Slight or intermediate enhancement of the cyst wall of endometriomas in 42, and significant enhancement in 35 were demonstrated. 54 cysts, 13 cystadenomas with 18 lesions and 4 malignant tumors with 5 lesions were diagnosed by preoperatively by CT. The accurate rate of CT characterization was 71.4%. Conclusion The certain morphologic characteristics of the ovarian endometrioma can be showed by CT in higher extent. It is critical to familiar with these characteristics to improve the diagnostic accuracy, and to avoid misdiagnosis.

Objective To investigate the value of multi-slice CT (MSCT) in diagnosing early acute appendicitis (AA).Methods From June 2008 to June 2011,abdomen MSCT images of 41 patients with acute simple appendicitis confirmed by surgery and pathology were evaluated retrospectively. Thirty-six patients with clinically confirmed normal appendix served as the control groups with 18 patients in complicated-normal-appendix (CNA) group and 18 patients in noncomplicated-normal-appendix (NCNA)group. The appendix was reconstructed by using multiplanar reformation (MPR) and curved planar reformation (CPR) techniques. The differences between early AA and normal appendix in appendiceal diameter,thickness of the appendiceal wall, maximum depth of the intraluminal appendiceal fluid (MDIAF), abnormal enhancement of the appendiceal wall, appendicolith and the periappendiceal abnormalities were evaluated and compared by using analysis of variance,R test and Chi-square test.Results The mean thickness of the appendiceal wall was (2.88 ±0.62),(2.58 -±0.50) and (2.73 ±0.53) mm in early AA,CNA and NCNA groups respectively,with no statistically significant difference among them ( F =1.73,P=0.19).The nean appendiceal diameter was (11.37 ± 1.94),(7.03 -±0.89),(6.75 ±0.63) mm,and median MDIAF was 4.05 (2.65-8.50),1.68 (0-.40),0 (0-1.90) mm in early AA,CNA and NCNA groups respectively,with statistically significant differences between early AA and the two normal appendix groups ( Z =7.02,7.24 ; P =0.00 ).The abnormal enhancement of appendiceal wall was found in 61.1％ (11/18) of early AA,16.7％ (3/18) of CNA and 11.1％ (2/18) of NCNA groups respectively,with statistically significant differences between early AA and the two normal appendix groups (x2 =12.83,P =0.00). Using a cutoff value of 7.8 mm of the appendiceal diameter and 2.6 mm of MDIAF for the early AA,the sensitivity,specificity and accuracy were 97.6％ (40/41),91.7％ (33/36) and 94.8％ (73/77),and 100.0％ (36/36),88.9％ (32/36) and 94.4％ (68/72),respectively.Conclusions MSCT is particularly useful for the diagnosis of early AA. When appendiceal diameter is greater than 7.8 mm,and MDIAF greater than 2.6mm,early AA can be diagnosed with confidence.

Objective To evaluate mesenteric muhidetector row CT angiography (MDCTA) in the diagnosis of acute mesenteric ischemia (AMI).Methods In this study,43 cases of AMI proven by clinical criteria,or operation and pathology underwent whole abdomen MDCT precontrast,arterial phase and venous phase scan with 0.6 mm collimation.The mesenteric arteries and veins were reconstructed by using volume rendering (VR),maximum intensity projection (MIP),thin slab maximum intensity projection (TSMIP) techniques,and abnormal CT angiography findings as well as abnormal bowel and mesentery were analyzed.Results It was found that AMI was caused by superior mesenteric artery (SMA) embolism (n =4),SMA thrombosis (n = 6),mesenteric and portal venous thrombosis (n = 13),SMA dissection (n =5),strangulated bowel obstruction (n = 10) and vasculitis (n = 5).MDCTA showed clearly the position,shape,severity and extent of the vascular occlusion,narrow and dissection.It could also demonstrate the abnormal course and direction of the vessels including vascular gathering,shift,tortuosity,retortion,and twist.Furthermore,the pathogenesis of various conditions including atherosclerotic plaque,emboli,thrombosis,dissection,tumorous invasion,strangulated bowel obstruction and vasculitis could be identified by MDCTA.Conclusion MDCTA can clearly demonstrate direct signs leading to AMI,and identify AMI and its etiology at early stage,with the combination with its indirect findings.

Based on the characteristics of medicinal chemistry and the training objectives of experimental teaching,to explore the teaching reform of comprehensive experiments in medicinal chemistry.This paper discussed the time of biginning comprehensive experiments,the choice of experimental article,the demands on teachers in comprehensive experimental teaching,and attention points of teaching management.

Objective To improve the diagnostic accuracy by analyzing the CT manifestations of ovarian cystadenoma .Methods The CT images of 57 patients with 62 ovarian cystadenomas proved by surgery and pathology were studied retrospectively . Results Of 62 ovarian cystadenomas, 26 cases with 31 tumors were serous,another 31 cases were mucinous . Unilocular and multilocular forms were seen respectively in 19(61.3%)and 12(38.7% ) of 31 serous cystadenomas, and in 3(9.7%)and 28(90.3%) of 31 mucinous cystadenomas.22 (71.0%) tumors were benign, and 9(29.0%)were of borderline and/or malignant transformation in 31 serous cystadenomas.23 (74.2%) tumors were benign, and 8 (25.8%) were of borderline and/or malignant transformation in 31 cases of mucinous cystadenomas.Benign cystadenomas were frequently round or oval cysts with thin regular wall and septa.Borderline or malignant transformation cystadenomas demonstrated predominately thick irregular wall or septa with projections.The overall preoperative accuracy of characterization was 48.4% in serous and 77.4% in mucinous cystadenomas.Conclusion Multilocular cystadenomas have the typical CT manifestations and CT is a high valuable procedure for imaging them, whereas unilocular cystadenomas, having similar CT findings with some other benign cystic lesions, are lack of enough characteristic features for CT correct characterization.

Objective : To investigate the achieved intrusion amount of the maxillary incisors and the influencing factors in clear aligner cases treated with extraction of premolars. Methods : This study has been reviewed and approved by the Ethics Committee, and informed consent has been obtained from patients. Thirty adult female patients who underwent extraction of the bilateral maxillary first premolars followed by clear aligner therapy were included. CBCT data before and after treatment were obtained, and three-dimensional reconstruction with registration alignment was performed. A spatial coordinate system was established, and the achieved intrusion amount was measured, followed by calculation of the intrusion efficacy. The factors related to the achieved intrusion amount were investigated through multiple linear regression analysis. Results : The overall efficacy of maxillary incisor intrusion was 54%, with the maxillary central incisors (48%) lower than the lateral incisors (59%), which was statistically significant (P<0.001). Regression analysis showed that the designed intrusion amount and the stepwise intrusion design were positively correlated with the achieved intrusion amount. The designed retroclination amount and use of class Ⅱ intermaxillary elastics were negatively correlated with the achieved intrusion amount. The initial overbite, overjet, crowding, upper central incisor inclination, amount of the first series of aligners, canine attachment type, posterior teeth attachment type and bite ramps had no significant correlation with the achieved intrusion amount. Conclusion In maxillary first premolar extraction cases treated with clear aligners, the upper central incisors have lower efficacy of intrusion movement than the lateral incisors. The achieved intrusion amount of maxillary incisors was influenced by multiple factors, which should be considered comprehensively for better vertical control in such cases.