Objective To investigate MR imaging characteristics of MELAS syndrome.Methods The clinical data and MRI features of 13 cases with MELAS syndrome were retrospectively analyzed.Results Multiple hypointense on T1WI and hyperintense on T2WI lesions were showed predominantly in the gray matter of the temporal, parietal and occipital lobes. The lesions crossed vascular boundaries. No stenosis and occlusion of main artery were displayed by MRA.Basal ganglia calcifications and cerebral atrophy with widening of ventricles were also frequent found. Increased ADC value of the leison on DWI and appearance of Lac peak on1H-MRS were useful in diagnosis.Conclusion There are some characteristics of MRI in patients with MELAS syndrome.Combined clinical informations with neuroimaging and muscle biopsy, the diagnosis of MELAS syndrome can be made correctly.

Microsatellite instability(MSI)was defined according to the frequency of positive findings in a panel of MSI markers.High frequency MSI(MSI-H)was the phenotype in which repeat sequences were extraordinarily unstable, and was considered to be the bona fide phenotype of DNA mismatch repair defection. However base substitutions in some well studied oncogenes or tumor suppressors were reported to be uncommon in MSI-H tumors. To explore this obvious contradiction, the relationship between MSI and KRAS gene mutations were studied in a panel of 76 human colorectal carcinomas, the whole exon of MLH1 and MSH2 were sequenced for MSI-H tumors. KRAS gene mutation was confirmed by similar frequencies in tumors of different MSI status. Intriguingly, all of the KRAS mutant MSI-H tumors harbored sequence alterations in MLH1gene, which was a key player in DNA mismatch repair system. This implied that in MSI-H tumors carrying MMR mutations, KRAS mutation were frequently and almost exclusively occurred. Furthermore, these MMR mutants were uniformly carrying a unique modification + jumping type MSI, which was different to MSI-H tumors without MLH1 or MSH2 gene mutations. This study shaded lights on the heterogeneity of MSI-H tumors, and implied the connection between modification type MSI and DNA mismatch defection.

Objective: Study the morphology and kinetics characters in breast diseases by using helical CT,to assess the value of differential diagnosis in benign and malignant breast diseases.Methods: Forty-three focuses in thirty-eight patients were detected by using double row detector CT with histopathologic correlation.Analyzed the characters of morphology,the time-density curve and the enhancement rate of all focuses.Results: Of the 43 focuses,breast cancers were twenty-eight and benign diseases were fifteen. There were eleven pieces and thirty-two masses.Lobulation signs and spicule signs were twelve respectively,among twenty-one malignant masses.One had spicule sign and two had lobulation sign among eleven benign mas-ses.Twenty breast cancers had Ⅲ type time-density curve,eleven benign diseases had Ⅰ type curve,and there were some overlaps on Ⅱ type curve.Enhancement rate(E) reflected the blood kinetics of breast diseases.E 1min and E 3min were better than E 3min in differentiating benign and malignant breast diseases.Conclusion:Lobulation signs and spicule signs are more often found in malignant lesions than in benign lesions.Early enhancement rate and time-density curve present some important information in differentiation.Synthesizing all these specialties can promote the diagnosis accuracy.

Objective To observe the MR findings of myxoid-round cell liposarcoma of the lower extremities and to evaluate therelationship between MR findings and pathologic features. Methods MR findings of 6 myxoid-round cell liposarcomas of the lowerextremities confirmed pathologically were retrospectively reviewed,including tumor's location,size,morphology,internal architecture and signal intensity characteristics on T_1WI,T_2WI and SPIR T_2WI and the pattern of enhancement.Results All tumors were located in thedeep space among skeletal muscles of the lower extremities,with unregular shape,sharp borber and thick septal structures.Tumors werehomogeneous or heterogeneous isointense on T_1WI and hyperintense on T_2WI relative to the signal intensity of skeletal muscles and heterogeneous enhancement after the injection of GdDTPA.Conclusion MRI may lead to a correct diagnosis of myxoidround cell liposarcoma of the lower extremities.

Objective To measure the right conus branch in adults with multi-slice CT.Methods 57 cases were detected with multi-slice CT coronary artery angiography. Such data as the length and diameter of the right conus branch, the distance from the origin of theright conus branch to the nearest aortic wall, and to the origin of the coronary artery on the axial images were measured,and the anglebetween the right conus branch and the distal segment of the coronary artery on the VRT image was also made.Results The distribution and shape of the right conus branches could be detected by CT, and with different methods thus data above could be gotten precisely. Conclusion There is a higher significance to detect and measure the right conus branch with multi-slice CT.

Objective To study the value of measurement of sinus node artery in adults with multi-slice spiral CT(MSCT).Methods 119 cases were examined by MSCT coronary artery angiography.The diameter of the sinus node artery,the distance from the origin of the sinus node artery to the origin of the coronary artery(S-O),to the origin of left circumflex branch(LO-O),and to straightly the aortic wall erectly(S-W) and the angle between the sinus node artery and the proximal segment of the coronary artery(the angle of S-C) were measured on axial and MIP images.Results The origin,morphological characteristics of the sinus node artery were shown clearly on CT coronary artery angiography,and the diameter,length,the distance of S-W,S-O and LO-O and the angle of S-C were measured precisely.Conclusion The parameters of the sinus node artery measured by MSCT are basically corresponded with those on anatomy,MSCT may be used to show the sinus node artery.

Objective To detect the meshwork of tiny lymphatic channels at bilateral vertebral body and ventral aorta at 3.0 Tesla and to probe the relationship between its detective ratio and some diseases.Methods Fat-suppressed T2-weighted imaging in 91 patients was performed at the upper abdomen. The meshworks of tiny lymphatic channels at bilateral vertebral body and ventral aorta on contiguous axial and coronal images were reviewed. The classifications of the lymphatic meshwork were made according to its width and length on coronal images. The differences in the detective ratios of the lymphatic meshwork between control group and the risk ones including portal hypertension group, choledochus obstruction group and malignant tumour group were analyzed.Results Right- or left-sided lymphatic meshwork at vertebral body or ventral aorta were 34.07%(31/91),32.97%(30/91),32.97%(30/91) and 43.96%(40/91) respectively. The detective ratio of the lymphatic meshwork on the side of the ventral aorta was higher significantly in the portal hypertension group than that in the control or malignant tumour one (P0.05). Conclusion Meshwork of tiny lymphatic channels at bilateral vertebral body and ventral aorta allows to be detected on fat-suppressed T2-weighted imaging at 3.0 Tesla, and the portal hypertension may influence the detective ratio of the lymphatic meshwork on the side of the ventral aorta.

This study was aimed to observe the effect of Compound Shi-Chang-Pu (CSCP) granula on behavior, structure changes of hippocampus with epileptic seizure of mice induced by pentyenetetrazole (PTZ). Sixty Kunming mice, which were half male and half female, were randomly divided into 6 groups, which were the blank control group, animal model, phenytoin (PHT) group, high-dose CSCP (4 000 mg·kg-1) group, middle-dose CSCP (2 000 mg·kg-1) group and low-dose CSCP (1 000 mg·kg-1) groups. The blank group and model group were given intragas-tric administration the same volume of saline, the others animals treated with continuous oral administration of drugs for 7 days. Intraperitoneal injection of PTZ (80 mg·kg-1) was given 1 h after the last medication to establish the a-cute epilepsy model (expect the blank control group). Observation was made on the influence of CSCP on incubation period, behavior degree and times of epileptic seizure among PTZ induced epilepsy mice, the structure changes of mice were detected by the brain tissue HE staining. The results showed that CSCP can improve the degree of seizure attack, prolong the incubation period of mild attack, and decrease Ⅳ and Ⅴ degree epileptic seizure, the PTZ in-duced epilepsy mice could damage the structure of hippocampus, reduce the number of cells, PHT and CSCP could ameliorate these changes. It was concluded that CSCP had certain inhibition on epileptic seizure mice induce by PTZ and ameliorate the damage of hippocampus. The antiepileptic mechanism still requires futher study.