Objective To study the value of reverse CT scan in eliminating the respiratory motion artifacts in the thoracic CT of the patients with chronic obstructive pulmonary diseases(COPD).Methods Fourty patients with COPD were randomly selected and underwent chest CT examinations with the technique of GR-Helical including directive and reverse CT scans.The images were blindly evaluated by three experienced doctors.Results In 40 cases,the respiratory motion artifacts were present in 17 cases,among them,70.59%(12/17) artifacts was in lower lung field,and 64.7%(11/17) artifacts occurred in the people over 60 years of age.The rate of artifact was 35% at directive scan,while it was reduced to 7.5% at reverse scan,the image quality was improved at 27.5%.There was statistical significance in eliminating respiratory motion artifacts between two scanning method (P＜0.05).Conclusion Reverse CT scanning can effectively eliminating or reducing the respiratory motion artifacts in lower lung field,it is the best choice of scanning mode in elderly patients with COPD.

Objective To evaluate the sensitivity and optimized scanning parameter of 64-slice spiral CT in detection of pulmonary nodules with different size and density. Methods Three groups of prosthesis nodules with diameter of 2.5～13 mm and different density (soft-tissue, low density, and ground glass opacity,GGO)were taken into the chest phantom equivalent to human tissue,then scanned with Philips Brilliance 64 scanner in standard dose(tube voltage:120 kV, tube current: 250 mAs)and low-dose(tube voltage:120 kV, tube current: 50, 30,and 21mAs) respectively. The radiation dose(CTDIw and DLP) of the scans, Hounsfield unit(HU) and standard deviation(SD) of CT values in different regions of the phantom, and visibility of the nodules was assessed and recorded.Results The radiation dose of 64-slices spiral CT scanning in low-dose(tube current 21～51 mAs) decreased to 8%～20% of which scanning in standard-dose(250 mAs). There was no statistical difference between the CT values in different regions of the phantom (P>0.05), while the SD of CT values was of statistical significantce (P<0.001) and SD increased with the increment of the density under different scanning parameters. None of the nodules besides of GGO nodules with 2.5 mm and 4 mm in size scanned at 21 mAs was invisible. Conclusion GGO nodules of 2.5 mm in diameter can be detected with 64-slice spiral CT using 30 mAs at experimental study, which might be the optimized dose for detecting pulmonary nodules.

Objective To investigate the effect of recombinant human endostatin(rh-Endostatin) combined with transcatheter arterial chemoembolization(TACE) on the growth and metastasis of the implanted hepatic tumor in rabbits.Methods Thirty New Zealand white rabbits were randomly divided into three groups (10 in each group)and VX_2 carcinomas were implanted in the left lobes of the livers. Fourteen days later, a catheter was inserted into the hepatic artery of rabbits with VX2 hepatic tumor and infusion was performed via the hepatic artery using physiological saline (group A), TACE (group B) and rh-Endostatin combined with TACE (group C),respectively. Five weeks later, all ribbits were sacrificed, the body weight and liver weight of animals were assessed, the hepatic index(HI) was calculated, the volume and necrotic area of the implanted tumor were measured. The presence of metastases in the liver, lungs were recorded. Results Five weeks after inoculation, the body weight of all animals decreased, the liver weight increased, His were 10.2±2.8, 8.5±6.1and 6.2±4.4 in groups A, B and C, respectively. The mean volume and necrostic areas of the implanted tumor were (36.2±3.4) cm~3 and (52.0±2.3)% in group A, (23.6±4.5) cm~3 and (63.6±3.5)% in group B, (10.9±5.1) cm~3 and (78.6±4.8)% in group C, respectively. There were statistical significance about tumor volume and necrostic areas of the tumors between group C and group A,B ( P<0.01). The numbers of metastases in the lungs were 50.3±31.3,53.6±35.1 and 16.8±18.4 , and the diameters of metastases in the lungs were (3.6±1.4) mm, (3.8±0.6) mm and (1.2±0.6) mm in groups A, B and C, respectively, the difference between group C versus other groups( P<0.01) was statistically significant. The differences of opportunity, tumor numbers and size of metastases in the liver were statistically significant. (P<0.01).Conclusion Treatment with rh-Endostatin combined with TACE can suppress the growth of tumor and tumor's metastases in lungs inVX2 implanted tumors of rabbits.

Objective To explore the ischemic myocardial perfusion and viability.Methods Ten successful pigs with myocardial infarction model underwent MRI first-pass myocardial perfusion examinations preoperatively and 24 hours,72 hours and one week postoperation.After MRI examinations,the experimental pigs were executed and the samples underwent TTC staining and pathological examination.Results The preoperative myocardial perfusion in the all of the 10 pigs was nomal,but there were myocardial perfusion decrease and defects in 8 experimental pigs after operation,the perfusion curves in the area with perfusion defects had no obvious peak,but there was gradual increase in the end of the performance.The perfusion peak of the area with perfusion decrease was lower than that of normal inferior and lateral myocardial wall(P＜0.05) and the peak perfusion time was delayed compared with that of normal inferior and lateral myocardial wall (P＜0.05).There was myocardial necrosis in the perfusion defects areas that was certified by TTC staining and pathological examination.The intersititial edema and myocardial degeneration could be seen in the perfusion reduced areas.Conclusion MRI fist-pass myocardial perfusion imaging combined with perfusion curve analysis can evaluate the perfusion changes of the regional myocardial microcirculation.

Objective To study the curative effect of ischemic necrosis of femoral head(III ,IV stage)by continuative administration of medicine through indwelling catheter in artery.Methods Thrombolysis in 19 cases with ischemic necrosis of femoral head(III,IV stage) were treated with continuative administration of medicines through indwelling catheter in lateral femoral circumflex and medial femoral circumflex artery and obturator arteriae using Seldinger technique.Results All patients were followed-up for 6～12 months.The curative effect was evaluated by angiography,the clinical symptoms and the change of bone.The ratio of the improvement of clinical symptoms was 75.8%,63% of the necrotic area of femoral head showed hyperplasia.Conclusion By continuative administration of medicine through indwelling catheter in artery in treating ischemic necrosis of femoral head (III ,IV stage) has remarkable therapeutic effect.

Objective To analyze the MRI features of fibrocystic breast disease (FBD). Methods 39 patients with pathologically proven FBD were retrospectively reviewed. The imaging protocol consisted of pro-contrast imagings and bilateral breast volume im-aging for breast assessme NT(VIBRANT). MRI features were interpreted based on the morphologic and enhancement kinetic de-scriptors defined on ACR DIRADS-MRI lexicon. Results There were 3 types on ACR BI-RADS-MRI lexicon in FBD,including 13 focal mass-type showing malignant enhancement kinetic pattern mostly;15 cyst-type with non-enhancement or mild enhance-ment,of them,1 case with periductal mastiffs showing strong enhancement and rapid up-slope and wash-out mimicking a breast cancer. 6 non-mass type usually showing benign enhancement kinetic pattern. In 5 patients,MRI did not show definite abnormal evi-dence. Conclusion MRI is of significant value in diagnosing FBD.

Objective To study the value of diffusion tensor imaging(DTI) in early assessment of prognosis of hypoxic-ischemicencephalopathy(HIE) in new infants. Methods 96 cases of full term infants with HIE underwent DTI examinations at 0～12 days and 6～36 months. Based on clinical diagnostic criteria, 96 cases were divided into three groups: mild, moderate and severe HIE groups. Fractional anisotropy(FA) values in the corpus callosum splenium and the posterior limb of internal capsules were measured. Results (1) Varying degrees of FA groups was significantly different from the same site, increased linearly with time,but the magni-tude of change was different;(2)When FA value of corpus callosum splenium in the cut-off point was ≥0.437,the sensitivity(SE) was 83.8% , the specificity(SP) was 18.6% , ROC area under the curve was 0.903 , 95% confidence interval was from 0.846 to 0.961,standard error was 0.029;when FA value of posterior limb of internal capsule in the cut-off point ≥0.391,SE was 86.5%, SP was 11.9% ,ROC area under the curve was 0.940,95% confidence interval was from 0.898 to 0.984,standard error was 0.022. Conclusion MR DTI examination is of significant value in evaluating early the prognosis of HIE in infants.

Objective To evaluate the value of MSCTA in combination with CTV in diagnosis of pulmonary embolism and deep venous thrombosis (DVT) of lower limb. Methods 47 patients with pulmonary embolism proved clinically were examined with MSCTA using 120 kV,210 mA,collimater of 0.75 mm and the automatic bolus traching technique,the speed of contrast agent infu-sion was 3～4 m/s after 170 s delayed,venous scan of lower limbs was performed. Results 47 cases were well perform the trunk of bilateral pulmonary artery, pulmonary lobar artery, pulmonary segemental artery, pulmonary inferior segmental artery could be showed by MSCTA, MPR, MIP and VRT. 363 arterial segments were involved and 31 cases accompanied with DVT. Conclusion MSCTA in combination with CTV is of significant value in detecting pulmonary embolism accompanied with deep venous thrombo-sis.

Objective To analyze the diagnostic value of MRI in injured meniscus of the knee. Methods MRI and arthroscopic findings of meniscus injury(116 menisci)in 49 cases were comparatively analyzed. Results Among 116 menisci of 49 knee joints,MR imaging showed 0 grade in 11, Ⅰ grade in 14, Ⅱ grade in 50, Ⅲ grade in 38(grade Ⅲa in 17 ,grade Ⅲ b in 11,grade Ⅲ c in 10),and Ⅳ grade in 3. Conclusion MRI is of important diagnostic value in meniscus injury of the knee.

Objective To study the changing of vertebral body marrow fat fraction(FF) in different age and sex and the relation-ship between FF and bone mineral densities (BMD). Methods Eighty-five healthy volunteers aged from 21 to 70 years old and twenty patients with osteoporosis based on T score after dual X-ray absorptionmetry examination underwent proton magnetic reso-nance spectroscopy (MRS) in L_3 vertebral bodies. The volunteers were divided into five groups according to the age(10 years and 16～18 cases in each group). Results The FF values in 21～30 years group,31～40 years group,41～50 years group,51～60 years group , >60 years group and the osteoporotic group were 30.7%±4.4%, 35.5%±6.8% , 41.9%±6.6%, 46.8%±5.5%, 51.7%±5.2% and 59.2%±7.4%, respectively. The FF values in L_3 vertebral bone marrow in men were high than that in women in the same age group (P<0.05) except >60 years group. There was negative correlation between marrow fat content and T score in osteoporotic group(γ=-0.6, P<0.01). Conclusion The vertebral marrow fat content in healthy adults was significantly in-creased with the aging. MRS may be used as a new way to evaluate the physiological and pathological process of bone marrow.