Objective To investigate the clinical value of MR diffusion tensor imaging (DTI) in evaluating diffuse axonal injury (DAI).Methods The DTI imaging data of DAI patients and healthy volunteers were analyzed retrospectively.Fractional anisotropy (FA) values were measured in corpus callosum,etc.The serum myelin basic protein (MBP) was detected.Results Compared to the control group,the FA values were lower in genu of corpus callosum,splenium of corpus callosum,anterior limb of the internal capsule,posterior limb of the internal capsule and thalamus in DAI group (P ＜ 0.01,P ＜ 0.05).The mean FA values of two groups were negatively correlated with serum MBP levels (r =-0.755,P =0.001).Conclusions DTI can noninvasively reflect the damages of white matter fibers in DAI patients,and it has importantly clinical significance in evaluating prognosis and therapeutic effect of DAI patients.

Objective To evaluate the clinical value of 3.0T magnetic resonance imaging (MRI) diffusion weighted imaging (DWI) on evaluation effect of neoadjuvant chemotherapy in advanced gastric cancer. Methods 3.0 T MRI DWI examination was performed in 42 cases of advanced gastric cancer diagnosed by gastroscopy and pathology, including 32 patients were examined with DWI both before and after chemotherapy. Lymph nodes of gastric cancer lesions and display ability of stomach were measured, and the area of the apparent diffusion coefficient (ADC) values in normal stomach and tumors were compared. ADC values were compared in the same patients before and after neoadjuvant chemotherapy and analyzed along with postoperative pathological examinations. Results In a total of 40 patients who received 74 DWI examinations, ADC values in tumor and lymph nodes were significantly higher than those in normal tissue. The ADC value in tumors was (1.348 ±0.278) ×10-3 mm2/s, and in 12 cases of stomach lymph node enlargement was (1.329±0.188) ×10-3 mm2/s. However, the average ADC value of normal stomach was (2.081± 0.189) ×10-3 mm2/s with significantly lower DWI than that of the former (P< 0.001). After chemotherapy, the ADC value in tumors was increased, which was (1.572 ±0.261) ×10-3 mm2/s (P< 0.001). After neoadjuvant chemotherapy, 16 patients received gastric cancer radical prostatectomy, and postoperative pathological TRG ratings of tumor were decreased with different extent. Tumor cell density (TCD) before treatment with an average of 4.45 ×10-5 / px2, which was downgraduated to 2.48 ×10-5 / px2 after chemotherapy and surgery. Negatively correlation between TCD values and ADC values were observed. Conclusion MRI DWI examination can effectively detect advanced stomach cancer and the associated lymph node enlargement. Comparison of tumor morphology and ADC values in advanced gastric cancer before and after neoadjuvant chemotherapy has clinical value in prognosis.

Rupture and bleeding of accessory hepatic aneurysms is clinically rare. Computed tomography angiography (CTA) or multislice reconstruction can provide reliable basis for clinical diagnosis. Interventional surgery is the main treatment method. A successful case of interventional embolization of ruptured accessory hepatic aneurysm in our hospital was reported. The accessory hepatic artery variation of this patient belongs to Michels type 4. The bleeding site of the variant artery was identified by CTA and digital subtraction angiography. Satisfactory results were obtained after interventional embolization and follow-up.

Objective To investigate the imaging features of Ewing's sarcoma and primitive neuroectodermal tumor (ES and PNET) in sacrum.Methods Imaging data were retrospectively collected and reviewed in 17 patients with ES and PNET confirmed by pathology.X-ray was performed in all patients,CT scans in 13 patients,and MR scans in 10 patients.Results All lesions were detected solitary and lateral.X-ray and CT features were lytic bone destruction in 12 cases,2 of them with bone sclerosis; one patient showed diffuse sclerosis.Soft tissue mass in pelvic cavity can be seen in 11 cases,9 of them with adjacent large blood vessels invasive and 4 patients with sacroiliac joints invasive.On post-contrast images,mild enhancement was found in 8 cases,and 5 patients with marked enhancement.MR images showed intermediate signal intensity on T1WI in 8 cases and heterogeneous moderate to high signal intensity on T2WI/fat suppression in 10 cases.DWI showed high signal intensity in 4 cases.Unlike CT scan,contrastenhanced MR images showed significant enhancement in 7 cases.Conclusions Ewing's sarcoma and primitive neuroectodermal tumor (ES and PNET) in sacrum have some specific imaging features.Imaging examination could provide reliable evidence for clinical diagnosis.

Objective To predict the astronaut organs radiation exposure and related health risks in the space radiation environment, the calculated method is studied. Methods A male voxel human model based on MRI and radiation data bank was build. The calculation was carried out with Monte Carlo particle transporting program GEANT4. Results The organ absorbed dose distribution and the effec-tive doses to the model in isotropic proton fields with energies ranges from 10 MeV to 500 MeV were obtained. Conclusion Based on the Chinese astronaut voxel model and the data set of proton spectrum measured in the space cabin, the cumulated dose in the model is gotten. The calculated skin dose is about 148.6 μGy/d, which is within in the range of 100 -300 μGy/d, published by USA and Russia.

Objective To summarize the experience of radical treatment of tetralogy of fallot in adults.Method Between Nov. 1985 and May 2005,115 patients over 18 years of age with tetralogy of fallot underwent total surgical correction.Longitudinal or oblique right ventriculotomy was used to ensure complete release right ventricular outflow obstruction and complete ventricular septal defect closure.Transannular patches were used in 74 patients,right ventricular outflow tract(RVOT) patches in 37 cases,primary closure of right ventricle in 5 cases,respectively.One patient had separate pulmonary main artery and RVOT enlargement.Results Seven patients had residual septal defect and 3 cases suffered from residual RVOT obstruction.Severe cardiac output syndrome occurred in 10 patients and 6 patients died early postoperatively with the mortality rate of 5.22%.Conclusion By careful surgical management,the treatment of total correction in adult patients may result in good effectiveness.

Objective To study the effects of ankle-foot retractor on ankle joint motion and equilibrium function of stroke hemiplegic patients.Methods 74 patients were divided into two groups: observation group (n=36) and control group (n=38). The control group was trainedby routine rehabilitation training program and electro-uprise bed, the observation group was trained by ankle-foot retractor based on routinerehabilitation training program. The effect was evaluated after 8 weeks. Results After training, either the observation group or the controlgroup showed significant improvement at motion of ankle joint, activity of daily living (ADL), and equilibrium function, but the observationgroup was better than the control group (P<0.001). Conclusion Ankle-foot retractor plays a positive role on motion of ankle joint, ADL andequilibrium function in stroke patients.

Objective To study the effect of motor imagery on balance rehabilitation in hemiplegics after stroke.Methods 20 hemiplegic patients who were in chronic stage(above 6 months)were randomly divided into two groups.Normal rehabilitation was performed in the whole stage and motor imagery was added in group A in stage Ⅰ and group B in stage Ⅱ.All patients were assessed with Berg Balance Scale(BBS),blance subscale of the Fugl-Meyer Assessment(FM-B),max affected limb-loading per weight and Functional Independence Measure(FIM)at the beginning and the ending of the every stage,respectively.Results The deference scores of BBS and FIM,as well as max affected limb-loading per weight between in the stage with motor imagery was better than those in the stage without motor imagery(P<0.01),as well as that of FM-B score(P<0.05).Conclusion Motor imagery can improve balance rehabilitation and activity of daily living in chronic hemiplegics.

Objective To analyze the value of dynamic contrast-enhanced MRI(DCE-MRI) parameters of Extended Tofts and Exchange model in the differential diagnosis of hepatocellular carcinoma (HCC) and hepatic metastases of colorectal cancer. Methods A retrospective analysis of 40 pathologically confirmed cases was conducted , including 25 cases of HCC and 15 cases of hepatic metastases of colorectal
cancer,all patients underwent DCE-MRI. Applying liver double blood supplement model , and respectively using Extended Tofts two-compartment model and Exchange model liver microvascular permeability parameters [volume transfer constant of the contrast agent(Ktrans), efflux rate from extracellular extravascular space to plasma(Kep), extravascular extracellular volume fraction(Ve)and blood plasma space volume fraction (Vp)] and the perfusion parameter hepatic arterial perfusion index(HPI) in the lesion parenchyma of HCC and metastases were calculated. We used t test to compare the differences of the parameters measured from the two types of tumors , statistically significant parameters between HCC and metastases were screened which compared with the gold standard of pathological findings in order to draw the ROC curves to evaluate the diagnostic efficacy of different model parameters, using χ2 test compared the diagnostic accuracy of optimal parameters between the two models. Results By using Extended Tofts and Exchange model , Ktrans value of HCC were (0.661 ± 0.402)/min and (0.604 ± 0.316)/min respectively, Ktrans value of hepatic metastases were (0.196±0.175)/min and (0.179±0.135)/min respectively;Vp value of HCC were (0.334±0.217) and (0.294± 0.098), Vp value of hepatic metastases were (0.089 ± 0.015) and (0.089 ± 0.022),respectively; HPI value of HCC were (0.680±0.281) and (0.769±0.245) , HPI value of hepatic metastases were (0.326±0.216), (0.373± 0.298), respectively. There were significant differences between HCC and hepatic metastases in Ktrans, Vp and HPI values in both models(P<0.05). There was not statistically significant difference between HCC and hepatic metastases in Kep, Ve values(P>0.05).Drawn ROC curves of Ktrans, Vp, HPI , the Ktrans value (area under the curve of 0.869) among Extended Tofts model parameters was selected as optimal parameter to identify HCC and hepatic metastases; the HPI value (area under the curve of 0.845) among Exchange model parameters was selected as optimal parameter to differentiate these two types of tumors.The diagnostic accordance rate of Extended Tofts model and Exchange model were 80.0%(32/40), 82.5%(33/40), respectively ; There was no significant difference between them(χ2=0.082,P=0.775). Conclusions Parameters including Ktrans, Vp, HPI of the Extended Tofts model and Exchange model in DCE-MRI perfusion can be used to identify HCC and hepatic metastases of colorectal cancer. Among these parameters, Ktrans of Extended Tofts model and HPI of Exchange model have higher diagnostic value in differentiating HCC and hepatic metastases of colorectal cancer.

Objective To study the safety and effectiveness of polymer-free sirolimus-eluting Nano stent in patients with unstable angina pectoris. Methods Three hundred and twenty-one patients with unstable angina pectoris were divided into Nano stent group(group A,n=157)and Endeavor resolute stent group(group B,n=164). The cardiovascular events were compared postoperative 12 months. The minimal intima cavity area and mini-mum bracket section area and neointimal area were compared postoperative 12 months by intravascular unltrasound (IVUS). Results There were 7 cases of cardiovascular events in group A and 6 in group B postoperative 12 months(P=0.727)and 2 patients in group A and 3 in group B were re-implanted stent because of restenosis post-operative 12 months(P=0.672). The neointimal area were(0.31 ± 0.11 mm2)in group A and(0.29 ± 0.12 mm2) in group B postoperative 12 months(P = 0.985). The minimal intima cavity area(P = 0.921)and the minimum bracket section area(P=0.934)were narrower postoperative 12 months than immediately after the operation in two groups. Conclusion With less cardiovascular events and being safe and reliable,the clinical effect of polymer-free sirolimus-eluting Nano stent implantation is similar to that of Endeavor resolute stent implantation.