Objective To study the clinical and MRI features of central pontine myelinolysis after liver transplantation.Methods 3 cases of orthotopic liver transplantation patients,displaying unconsciousness,drowsiness,reduced muscle strength of both lower extremities 3 to 21 days after the operation respectively,went through MRI scan in 2 days.Results MRI showed that symmetric long T1 and T2 signals,high-signal-intensity DWI and low-signal-intensity ADC were found in central pontine region.The cerebral cortex was involved in 2 cases,and abscess in basal ganglia appeared in 1 case.MRI examination showed that 2 cases had decreased lesion range,clear boundary and equal-signal-intensity DWI 35 days and 2 months respectively after.Conclusion MRI is valuable for the diagnosis of the patient with central pontine myelinolysis after liver transplantation.

Objective To study the advantage of magnetic resonance imaging(MRI) in diagnosis of complications following liver transplantation.Methods The MRI appearances were analyzed retrospectively in seventy-eight patients with postoperative complications after liver transplantation which was confirmed by operation,hepatic biopsy,angiography and cholangiography.Results The symptoms of skin and sclera jaundice,fever and belly pain were found in sixty-four patients.Liver function was abnormal in laboratory tests.Fourteen were non-symptom with normal liver function.By analyzing the MRI images,the results were found including hepatic portal vein anastomosis stenosis(n=21),hepatic arterial anastomosis stenosis(n=10),inferior vena cava anastomosis stenosis(n=1),bile duct anastomosis stenosis(n=15),bile duct non-anastomosis stenosis(n=5),transplant rejection(n=17),hepatic carcinoma recurrence(n=9).Conclusion MRI can be revealed hepatic vessels and bile ducts stenosis and dilations;it's the best device in diagnosis of complications after liver transplantation.

Objective To research the mobile medical units' portable equipment for Olympic safeguard service. Methods Relevant scientific literatures and combined the actual medical supporting tasks during the Olympic safeguard service were reviewed,and studied the portable equipments,instruments and medicines of the mobile medical units. Results Combined with the mobile medical units' actual characteristics,the principle was small size and efficient,multifunctional,simple and practical. The portable equipment was not only first-line treatment,but also taken into account advanced treatment,they can adapt to different environment and better coordination of the tasks to be performed. Conclusion Perfect portable equipment is very important way to enhance the whole capacity of mobile medical units for medical supporting in Olympic safeguard service.

Objective To explore the metabolic characteristic of prostate cancer (PCa) in central gland with magnetic resonance (MR) spectroscopic, and evaluate the value of MRS in the differential diagnosis of benign prostatic hyperplasia nodus. Methods MR images were performed in 38 cases with prostate disease by 3.0T MR, 11 cases with PCa in central gland and 27 cases with benign prostatic hyperplasia nodus. All the cases were scanned by routine, then by the combined MRS. MRS findings were reviewed in 27 cases with benign prostatic hyperplasia (BPH) and 11 cases with PCa (3 in central gland origin, 8 with large tumor invading both peripheral zone and central gland). (Cho+Cr)/Cit ratios of PCa and BPH were retrospectively measured, (Cho+Cr)/Cit of PCa voxels were compared with that of BPH voxels. Results Significantly higher choline levels and lower citrate levels were observed in central gland of PCa compared with BPH. In the glandular BPH region, the amount of Cit was high; while in the stromal region, the Cit and Cho level was much lower. The average (Cho+Cre)/Cit values of PCa and BHP were 1.94±1.43 and 0. 83±0. 28 respectively, the difference in ratio between both was statistically significant (P＜0. 01). Conclusions The combined use of MRI and MR spectroscopy is propitious for differentiating prostate cancer in central gland and benign prostatic hyperplasia nodus and for increasing the diagnostic accuracy of prostate cancer.

Objective To observe the value of dynamic contrast-enhanced MR angiography (DCE MRA) with gadobenate dimeglumine in evaluation of vascular complications after living donor liver transplantation. Methods Thirty-four consecutive patients were examined with MR after living donor liver transplantation. First, 1 ml gadobenate dimeglumine was injected in vein to infer the time of gadobenate dimeglumine reaching abdominal artery performing testbolus. Then a scan with three-dimensional T1-weighted fast low-angle shot (3D-FLASH) sequence was performed. Four phases in series from arterial period were scanned and every phase paused 10 s to obtain images of the arterial, portal venous and hepatic venous systems. The original and maximum intensity projection (MIP) reconstructed images, categorized vessel visualization on a five-point scale and observed stoma of hepatic artery, portal venous and hepatic venous inferior vena cava, diameter and display of surrounding vessels were observed. The results were compared with those of digital subtraction angiography (DSA), ultrasound and clinical data. Results Overall vessel visualization assessment demonstrated good or very good ratings for the majority of patients. Among all 34 patients, hepatic artery stenosis was found in 4, portal vein stenosis in 6, portal vein thrombosis was detected in 2, while middle hepatic veins stenosis was detected in 1 patient, among whom 10 patients were confirmed with DSA, 4 with surgery, the others with ultrasound or follow-up. Conclusion Gadobenate dimeglumine DCE MRA is a highly accurate, noninvasive tool for evaluation of vascular complications after living donor liver transplantation, may be regarded as the first choice in postoperative evaluation.

Objective To investigate the feasibility of measuring liver volume with Argus methoct Methods Thirty-two healthy liver transplant donor candidates underwent liver MRI on a 3.0 T MR unit.Volume interpolated body examination(VIBE)was performed after the administration of gadobenate dimeglumine.The VIBE data was transferred to the diagnostic workstation,and then multiple planar reconstruction(MPR)images were acquired.Firstly.two observers manually drawn the liver shape and calculated three volumes:the whole liver volume and right lobes volumes include middle hepatic vein (MHV)and exclude MHV,respectively.Secondly,the same data was transferred to Argus software.calculated that three volumes.Each measurement time was recorded.Actual graft volume(the right lobe)wag measured during surgery.The correlation between right lobes volume of two measurements and actual graft volume was analyzed.The time needed for Argus and that needed for manual method were compared with paired t test.Results The right lobe volumes measured by Argus,manually and surgery method were (813±187),(807 ± 181)and(713 ± 137)mm3,respectively.Argus method and manual method showed good correlation with surgery method,and the correlation coefficients were 0.897(Argus method)and 0.884(manual method),respectively.The time for manual method and Argu8 method were(44.3 ±2.7)and(12.2.±1.0)min,respectively.There was significant difference between Argus and manual methods (t=76.39,P＜0.05).Conclusion Compared with manual method,use of the Liver volumetric measurement by Argus software not only correlated well with Actual graft volume,but also saves time.Argus has potential clinical value for volumetric measurement in living liver transplant donors.

Objective To compare conventional T2-weighted MR cholangiography (T2WI-MRC) with gadobenate dimeglumine enhanced T1-weighted MR cholangiography(CE-MRC) for evalution of biliary anatomy in liver transplant donor candidates. Methods Thirty-two healthy liver transplant donor candidates were examined with two MR cholangiogaphic methods. For T2WI-MRC, a three-dimensional turbo spin-echo sequence and oblique coronal heavily T2-weighted thick-slab turbo spin-echo imaging sequence were performed. For CE-MRC, three-dimensional fat-suppressed spoiled gradient-echo sequences were performed, with a time delay of 60 minutes following the administration of gadobenate dimeglumine. To compare the depiction of biliary duct anatomy and the artifact caused by intestinal liquid and breathing between the two methods. Intraoperative cholangiography was the reference-standard examination. Results The both methods depicted the biliary anatomy correctly in all 9 cases. The both methods showed the third branches of intrahepatic biliary duct clearly. T2WI-MRC showed interhepatic bihary duct before the third branches in 28 cases (87.5%), CE-MRC showed the same finding in 14 cases (43.8% ). T2WI-MRC showed common bile ducts intermitantly in 2 cases, which were normal in CE-MRC and intraoperative cholangiography. Intestinal liquid affected the image quality of biliary duct in 6 cases (18.8%) performed with T2WI-MRC, but none with CE-MRC. The artifacts caused by breathing were not obvious in the either method. Conclusion T2WI-MRC and CE-MRC both can be used to evaluate bihary anatomy of liver transplant donor candidates, but CE-MRC appears to be more accurate than T2WI-MRC.

Objective To explore whether dynamic contrast-enhanced MRA (DCE MRA) can provide an effective assessment of renal vascular in living donors before transplantation.Methods Thirty five healthy living renal donor candidates were scanned on MR system before transplantation.After injection of Gd-DTPA 1 ml in vein, a test-bolus scan was used to get the time delay of Gd-DTPA reaching renal artery.Then, a 3D T1-weighted fast low-angle shot sequence (3D FLASH) was performed in the coronal plane.The 3D FLASH scan would repeat four times with an inter-phase of 10 seconds.Thus, the imaging of the renal arterial, venous and collecting systems were got.Two radiologists observed renal arteries and veins on original imaging and MIP reconstructed imaging.The quality of MR angiography was evaluated on a fivepoint scale and the vascular anatomy or variations of the arterial and venous systems were recorded, using intraoperative findings as a standard of reference.Results The quality for all MRA was good or very good for the most of living renal donors.Among 70 renals, several variations of vascular were found, including 5 left accessory artery, 9 right accessory artery, 3 left proximal arterial branch and 6 right proximal arterial branch.Among 70 renal veins, 1 right accessory veins and 2 left varieocele were observed.One small accessory artery of right kidney was missed with DCE MRA, but identified by operation.Conclusion DCE MRA was noninvasive tool for evaluation of the renal vasculature and variations with high accuracy.It would be a good modality in preoperative evaluation of living renal donors.

To investigate the value of MRI for the diagnosis of achilles tendon closed rupture. 1.5T Maestro Class MRI scanner was used for the conventional scanning of 15 patients confirmed with achilles tendon closed ruptures by operation, and then the findings by imaging were compared with those by operation. The 15 patients proved with achilles tendon closed rupture, including 4 cases of incomplete rupture and 11 cases of complete rupture. MRI could display clearly the changes in morphology and signal of incomplete or complete closed ruptures of Achilles tendon, and the results were consistent with those by operation. MRI can make an accurate display of the lo-cation and extent of achilles tendon rupture.

Objective To explore the advantages of Argus method by comparing the accuracy and timeliness of Argus and artificial methods for measuring femoral head necrosis area in MRI scanning.Methods Totally 17 patients (31 hips) were measured with Argus and artificial methods respectively for the necrosis area, and then the measuring results and time were compared, and the correlation was investigated between the results and the patients' pain degree, along with that between the results and the extent of femoral head collapse.Results The necrosis area ratios determined by Argus and artificial methods were (33.5±4.08)%and (34.6±4.06)%respectively, with no statistical difference between the ratios (P>0.05). The time consumed by artificial method was (21.3 ±3.62)min, significantly longer than (7.89 ±1.03)min by Argus method, with P<0.001. Regression analysis proved that the necrosis areas were positively correlated with the patients' pain degree, and the correlation coefficient by Argus method was 0.807 8, more than 0.740 9 by artificial method. The femoral heads of 11 cases(16 hips) collapsed in the follow-up period, the necrosis areas were positively correlated with the patients collapse level, but the correlation coefficient by Argus method was 0.783 8, more than 0.726 7 by artificial method.Conclusion Argus method gains high accuracy and timeliness when used in MRI scanning of femoral head necrosis area, and thus is worth popularizing clinically.