CBS(Case Based Study)is a new teaching method,which is based on the case given.It requires students to answer questions according to the case. In the teaching,the students who are divided into groups,seek for resolvent by themselves. They should combine the information provided in the case,find the key answer and the relationship.The students gain the knowledge by reviewing and studying in the textbook,then analyse and solve questions with them. The application of CBS could make knowledge more relatively and systematic, moreover,it also make study more actively and initiatively.

Adolescent ; Adult ; Environmental Exposure ; Female ; Humans ; Inhalation Exposure ; Male ; Middle Aged ; Nasopharynx ; pathology ; Sulfuric Acid Esters ; poisoning ; Young Adult

Objective To evaluate the clinical significance of CT angiography(CTA)in the diagnosis of arterioportal shunts(APS)associated with hepatocellular carcinoma(HCC).Methods One hundred and twenty-seven consecutive HCC patients accepted both dynamic enhancement CT and DSA examinations.The interval between CT and DSA exam was from 3 to 15 days.Based on transverse CT images in hepatic artery phase,CTA was performed for all the patients.By contrast with DSA results,the capabilities of transverse CT and transverse images combined with CTA in APS diagnosis were analyzed. Results In all 127 HCC cases,52 cases with APS were confirmed by DSA(40.94%),33 with central type of APS and 19 with peripheral type.Diagnostic sensitivity of APS based on transverse CT and combined CTA with transverse CT images were both 94.23%(49/52).However,specificity was 84.00%(63/75) and 97.33%(73/75),respectively,accuracy was 88.19%(112/127)and 96.06%(122/127),the predictive value of positive cases was 80.33%(49/61)and 96.08%(49/51),and the predictive value of negative cases was 95.45%(63/66)and 96.05%(73/76).Combined with CTA,false positive cases of 4 central type of APS and 6 peripheral type of APS were excluded which were demonstrated by transverse CT images.By contrast with DSA,the coincidence rate of the type of APS diagnosed by transverse images combined with CTA was 88.46%(46/52),including 90.91%(30/33)of central type of APS and 84.21%(16/19)of peripheral type.The supplying arteries of central type of APS were intuitively displayed by CTA in 23 cases,19 from proper hepatic artery and 4 from gastro-duodenal artery.Conclusion CTA techniques based on the dynamic enhancement CT exams could effectively promote the specificity and the accuracy of APS diagnosis.

Catheter Ablation ; Child ; Heart Septal Defects, Atrial ; surgery ; Humans ; Imaging, Three-Dimensional ; Male ; Tachycardia, Supraventricular ; surgery ; Tomography, X-Ray Computed

BACKGROUNDThe diagnosis of diffuse hepatic lesions in early stage is a tough task at any time for clinical conventional imaging. Magnetic resonance diffusion-weighted imaging (MR DWI) can detect the changes of tissue structure at molecular level. This study was designed to determine the value of DWI in the diagnosis of diffuse liver lesions in early stage.

METHODSDiffuse liver lesions were induced by diethylnitrosamine in 42 rats of test group. Fourteen rats in control group were fed with pure water. Dynamic changes of MR DWI were observed every week in both groups during the early stage of diffuse liver lesions (1 to 12 weeks after drug administration in the test group). Apparent diffusion coefficient (ADC) values of liver parenchyma in different stages and pathologic changes were analyzed.

RESULTSThe process of diffuse hepatic lesions in the test group was classified into three stages according to pathological changes, namely hepatitis, hepatic fibrosis and cirrhosis. No obvious morphological changes were shown by conventional imaging in both groups during this stage. But MR DWI demonstrated heterogeneous signal changes in early stage of hepatic cirrhosis in the test group. No significant change of ADC values was found in the control group between different weeks (P > 0.05). The ADC values of the test group declined from the fifth week, and after the tenth week the ADC values were significantly different between the test and control groups at gradient factor (b) value 300 sec/mm(2) (P < 0.05). At b value 600 and 1000 sec/mm(2), significant difference was seen between the two groups from the sixth week onward. The range of ADC value of the groups was (1.7 - 0.9) +/- (0.40 - 0.04) mm(2)/sec (b = 600) and (1.38 - 0.75) +/- (0.07 - 0.35) mm(2)/sec (b = 1000), respectively. Dominant pathological changes included swelled hepatocytes within 1 to 4 weeks after the administration of diethylnitrosamine in the test group, hyperplasia of fibrous tissues in 5 - 8 weeks and formation of cirrhotic nodules in 9 - 12 weeks.

CONCLUSIONSMR functional DWI could detect diffuse liver lesions earlier than conventional morphological imaging. ADC value as a marker for early diagnosis of diffuse liver lesions could also be used to inspect changes of the lesions.

Animals ; Diffusion ; Diffusion Magnetic Resonance Imaging ; Liver Diseases ; diagnosis ; pathology ; Male ; Rats ; Rats, Wistar

Atrial Fibrillation ; surgery ; Catheter Ablation ; adverse effects ; Female ; Humans ; Middle Aged ; Pleural Effusion ; pathology ; Postoperative Complications ; Pulmonary Veins ; surgery

OBJECTIVETo introduce the technique of transarterial interventional embolization treating for arteriovenous malformations (AVM) in the face.

METHODSFrom April 1998, 17 patients have been treated with this method. Seldinger's maneuver was used in this series. Of them, 11 cases received only interventional embolization; 6 cases received both interventional embolization and surgical resection.

RESULTSThe interventional embolization was effective in all the 17 cases, which was confirmed by immediate angiography. Their clinical symptoms were gradually relieved. Interventional embolization obviously decreased hemorrhage during surgical resection.

CONCLUSIONSInterventional embolization provides a new way for the treatment of AVM. Preoperative embolization can lower the surgical risk as it obviously decreases hemorrhage during the surgical procedure.

Adolescent ; Adult ; Arteriovenous Malformations ; diagnostic imaging ; therapy ; Child ; Embolization, Therapeutic ; methods ; Face ; blood supply ; Female ; Humans ; Male ; Radiography, Interventional

Adult ; Apoptosis ; drug effects ; Benzene ; poisoning ; Biomarkers ; analysis ; Bone Marrow Cells ; drug effects ; Female ; Flow Cytometry ; Humans ; Leukocytes, Mononuclear ; drug effects ; Lymphocytes ; drug effects ; metabolism ; Male ; Micronuclei, Chromosome-Defective ; drug effects ; metabolism ; Occupational Exposure ; analysis

Objective To observe the effects of genistein and 17?-estradiol on microstructure of cancellous bone in ovariectomized (OVX) rats.Methods Ninty 7-month-old SD rats were randomly divided into baseline group,ovariectomized (OVX),sham-operated (SHAM),17?-estradiol treated (10?g?kg~(-1).day~(-1),EST) and genistein treated (5 mg?kg~(-1)?day~(-1),GEN) groups,and were killed at the beginning of the experiment,the 3rd and 15th week after operation.MicroCT scanning was performed on the left tibia in vitro.The regions involving 0.5 mm slice thickness and 1.6 mm distal to the tibial growth plate were selected as the regions of interest.Results At the 3rd week after operation,the tissue bone mineral density (tBMD) and trabecular thickness (sTh.Th) in group GEN were significantly higher than those in OVX and EST groups (all P

OBJECTIVETo investigate the value of Diffusion-Weighted Imaging (DWI) in the diagnosis of early stage liver diffuse lesions.

METHODSDiethylnitrosamine (DEN) was used to induce liver lesions in rats. Sequential DWI studies were performed on the livers from 1 to 14 weeks after DEN was administered through drinking water. Comparing studies with a blank control group was set and pathohistological examinations of the livers were performed.

RESULTSNo obvious routine MRI morphological change was found in either group during this period, but DWI demonstrated heterogeneous changes in the test group at the cirrhosis stage. There was no significant alteration of the apparent diffusion coefficient (ADC) value in the control group during this period (P > 0.05). The ADC values of the test group began to decline from the fifth week. Until the tenth week, the ADC value of the test group decreased drastically and when b = 300 s/mm2 statistic, the results showed an obvious difference between the two groups. There were also differences between the ADC values at the 10th, the 9th and the 1st weeks of the test group (P < 0.05). When b = 600 s/mm2 and 1000 s/mm2, significant differences were found after the sixth week between the two groups (P < 0.01). The main pathohistological liver change in the test group during the 1 to 4 week period after DEN was administered was swelling of hepatocytes; during the 5 to 8 week period it was fibrous tissues hyperplasia, and in the 9 to 14 week period it was cirrhotic nodule formation.

CONCLUSIONMR functional DWI could detect liver diffuse lesions earlier than conventional MR imaging. Measurement of ADC value may be of use in early diagnosis of liver diffuse diseases and for monitoring the changes of the lesions.

Animals ; Chemical and Drug Induced Liver Injury ; Diethylnitrosamine ; Diffusion Magnetic Resonance Imaging ; methods ; Liver Diseases ; diagnosis ; pathology ; Male ; Rats ; Rats, Wistar