Objective To analyze the correlations between liver lipid level determined by liver 3.0 T 1H-MRS in vivo and influencing factors using multiple linear stepwise regression. Methods The prospective study of liver 1H-MRS was performed with 3.0 T system and eight-channel torso phased-array coils using PRESS sequence. Forty-four volunteers were enrolled in this study. Liver spectra were collected with a TR of 1500 ms ,TE of 30 ms, volume of interest of 2 cm ×2 cm ×2 cm, NSA of 64 times. The acquired raw proton MRS data were processed by using a software program SAGE. For each MRS measurement, using water as the internal reference, the amplitude of the lipid signal was normalized to the sum of the signal from lipid and water to obtain percentage lipid within the liver. The statistical description of height, weight, age and BMI, Line width and water suppression were recorded, and Pearson analysis was applied to test their relationships. Multiple linear stepwise regression was used to set the statistical model for the prediction of Liver lipid content. Results Age (39.1 ± 12. 6) years, body weight (64.4 ± 10. 4) kg,BMI (23.3 ±3.1) kg/m2, linewidth (18.9 ±4.4) and the water suppression (90.7 ±6.5)% had significant correlation with liver lipid content (0.00 to 0.96%, median 0. 02% ), r were 0.11,0. 44,0. 40,0. 52, - 0. 73 respectively(P < 0. 05 ). But only age, BMI, line width, and the water suppression entered into the multiple linear regression equation. Liver lipid content prediction equation was as follows: Y =1.395-(0.021 × water suppression) + (0.022 × BMI) + (0.014 × line width) - ( 0. 064 × age),and the coefficient of determination was 0.613, corrected coefficient of determination was 0.59. Conclusion The regression model fitted well, since the variables of age, BMI, width, and water suppression can explain about 60% of liver lipid content changes.

Objective To explore the effect of body mass and body mass index (BMI) on proton hepatic MRS water suppression at 3.0T. Methods The prospective study of hepatic proton MRS was performed with GE Signa Excite HD 3.0T system and eight-channel torso phased-array coils using PRESS sequence in 44 healthy subjects. Liver spectra were collected with TR of 1500 ms, TE of 30 ms, VOI of 2 cm×2 cm×2 cm and NSA of 64 times. Areas and heights for metabolites resonances were caulculated. Results Group with small mass has lower height ([161.2±8.5] cm vs [167.7±6.2])cm, lower BMI ([20.8±2.3] kg/m~2 vs [25.6±2.6]kg/m~2), better water suppression effect (min-max: 90-96 vs 65-94;median: 94 vs 93), smaller height (min-max: 1.41×10~4-5.76 ×10~5 vs 3.45×10~4-1.75×10~6;median: 9.00×10~4 vs 2.58×10~5) and integrated area (min-max: 4.27×10~4-2.00×10~7 vs 1.24×10~5-5.00×10~7;median: 2.64×10~5 vs 1.19×10~6)of Lip2 than larger weight group. Standardized lipid content (min-max: 0-0.11 vs 0-0.96;median: 0.01 vs 0.04) was less. Group with lower BMI had lower weight ([55.2±8.2]kg vs [71.2±7.8]kg), smaller age ([33.2±11.9]years vs [45.6±9.4]years), better water suppression effect(min-max: 90-96 vs 65-95;median: 94 vs 93) smaller of height (min-max: 1.41×10~4-5.76×10~5 vs 3.45×10~4-1.75×10~6;median: 7.37×10~4 vs 2.11×10~5) and integrated area (min-max: [4.27×10~4-2.00×10~7] vs [1.24×10~5 -5.00×10~7];median: 2.64×10~5 vs 1.19×10~6) of Lip2 than larger weight group. Standardized lipid content (min-max: 0-0.08 vs 0.01-0.96;median: 0.01 vs 0.04) was less. There was significant correlation among water suppression, weight (r=-0.478, P=0.001) and BMI (r=-0.494, P=0.001). Conclusion Lipid accumulation in the liver may be the result of increased fat portion of the body depending on mass and BMI, and hinder to achieve effective water suppression.

Objective To evaluate the effect of intravenous Gd-DTPA on 3.0T proton MR spectroscopy (MRS) water suppression and shimming. Methods Prospective study of proton MRS was performed with GE Signa Excite HD 3.0T system and eight-channel phased-array coils with PRESS sequence (head, liver and kidney, respectively). Routine auto prescan program was operated to record full width half maximum (FWHM) and water suppression (WS%). Routine scan was performed after injection of Gd-DTPA, then prescan program was reoperated to record FWHM and WS%. The data of FWHM and WS% in head, liver and kidney were compared between before and after injection of Gd-DTPA with the Wilcoxon matched pairs signed test. Results WS% of spectroscopy of head and liver after administration of Gd-DTPA decreased significantly (T_+=12, T_-=66, P=0.02; T_+=0, T_-=45, P=0.007). The effect of shimming of kidney after administration of Gd-DTPA was poor (T_+=0, T_-=435, P<0.001) and WS% of spectroscopy of kidney after administration of Gd-DTPA decreased significantly (T_+=0, T_-=435, P<0.001). Conclusion WS% of spectroscopy in head, liver and kidney can be impacted negatively by Gd-DTPA. Gd-DTPA has great influence on shimming of spectroscopy of kidney, but has little influence on shimming of spectroscopy of head and liver. It is better to acquire MRS data before administration of contrast medium in kidney.

Objective To observe the changes of hepatic CT perfusion parameters and their correlation with serum aspartate transaminase( AST),alanine transaminase(ALT) and alkaline phosphatase (ALP) in a rabbit hepalic ischemia reperfusion injury (IRI) model.Methods Hepatic IRI was produced in rabbits by inducing left liver lobe ischemia (60 min) followed by 6 h,12 h and 24 h reperfusion (6 rabbits were used for each reperfusion interval ).Additional 6 rabbits were served as sham-operatedcontrols.All the rabbits were scanned with a dynamic iCT protocol.Blood samples were taken from the superior mesenteric vein to measure the levels of serum amylase (ALT,AST,and ALP) in various groups,and liver samples were taken for histological examinations after scanning.One-way analysis of variance (ANOVA) was used to determine differences between groups.The correlations of CT perfusion parameters with serum levels were analyzed using Pearson correlation coefficient.Results Heterogeneity of CT perfusion patterns appeared in the 6 h groups,which presented as low enhanced area [ ( 25.1 ± 9.3 ) ml · 1min-1 · 100mg-1].In reduced perfusion regions of IRI group,HAP of 12 h IRI group [ ( 19.5 ± 13.6) ml · min-1 · 100 mg-1],24 h IRI group [(8.0+2.7) ml · min-1 · 100 mg-1 ],HPP of 6 h IRI group [(10.8±5.5) ml · min-1 · 100 rng-1],12 h IRI group [(14.4±5.2) ml · min-1 · 100 mg-1],24 h IRI group [(7.8±3.3) ml · min-1 · 100 mg-1] and TLP of 6 h IRI group [(35.9 ±14.0) ml ·min-1 · 100 mg-1 ],12 h IRI group [ (33.9 ± 16.1) ml · min-1 · 100 mg-1 ],24 h IRI group [ (16.0 ±5.5) ml · min- 1 · 100 mg-1 ] were lower than those of sham group [ HAP (21.2 + 10.5 ) ml · min-1100mg-1,HPP(63.5±24.0) ml · min-1 · 100 mg-1,TLP (81.4±24.8) ml · min-1 · 100 mg-1](F=8.376,25.950,16.925,P＜0.01).However,HPI of 6 h IRI group [(65.9±3.9)％],12 h IRIgroup [ (54.2 ± 16.7)％ ],and 24 h IRI group [ (48.9 ± 10.0)％ ] were higher compared to sham group [ ( 24.1 ± 7.5 ) ％ ] ( F =43.664,P ＜ 0.01 ).But,the perfusion parameters in the relatively normal area of IRI groups showed decline compared with sham group.The levels of AST,ALT and ALP in IRI groups were significantly higher than those in the sham group ( P ＜0.05).In poorly enhancing tissues,TLP and HPP of IRI groups were inversely correlated with AST and ALP respectively ( P ＜ 0.01 ),and HPI was closely related to the increase of AST ( r =0.751,P ＜ 0.01 ).Conclusion These results demonstrate CT perfusion is sensitive to detect the hemodynamic changes.Perfusion parameters are closely correlated to the degree of liver injury in the rabbit IRI model.

Objective To evaluate 3.0 T MR DWI techniques in detecting the lesions of pre and post-radiofrequency ablation of the rabbit liver VX2 tumors. Methods Twenty two New Zealand white rabbits were used in this experiment. Twenty tumor fragments were implanted into the livers of 20 rabbits respectively. Two normal rabbits were used as controls for radiofrequency ablation of the normal liver. 3.0 T MR DWI was performed 14 to 21 days after tumor implantation (mean, 17 days) in the tumor-bearing animals. Radiofrequency ablation was performed in the 18 tumor-bearing animals and in the two healthy animals. 3.0 T MRI and DWI were performed 7 to 10 days after radiofrequency ablation (mean, 8 days).Pathology was obtained immediately after the completion of post-radiofrequency ablation MR imaging. The MRI features and ADC values of pre- and post -radiofrequency ablation lesions in the liyers with VX2 tumors and normal rabbits were analyzed and correlation was made with histopathologic findings. Analysis of variance repeated measures were performed in analyzing the differences among the ADC values of different tissues with the same b value. Results All 20 rabbit liver models of VX2 tumors were constructed successfully. One rabbit died of anesthetic overdose, another one showed necrosis within the implanted tumor. All 18 untreated VX2 tumors had predominantly low or iso-signal intensity on T1 WI and high signal intensity on T2WI. All 18 VX2 tumors and 2 normal rabbits were treated by radiofrequency ablation successfully. Lesions treated by Radiofrequency ablation displayed low signal intensity on T1 WI, and high signal intensity on T2WI. Seven to 10 days after radiofrequency ablation, lesions varied from having low signal intensity to slightly increased signal intensity on T1 WI, with areas of mixed ( high, intermediate, and low) signal intensity. A peripheral rim of high signal intensity with varying thickness on T2WI correlated with granulation tissue, which exhibited intense enhancement on contrast-enhanced images. Areas of low to intermediate signal intensity within the lesion on T2WI corresponded to coagulation necrosis. The tumor tissue appeared as areas of peripheral nedularity, with intermediate to high signal intensity on T2-weighted images and DWI. The tumor specimen was gray, among the tumor tissue, there were hyperplastic vessels,and granulation tissue. When b value was 600 s/mm2 , the ADC value of viable tumor (9 cases), necrosis (18 cases), granulation tissue ( 18 cases), normal liver tissue ( 18 cases) were ( 1. 227 ±0. 140) × 10-3,(0. 702 ± 0. 050)×10-3, ( 1.918 ± 0.124) × 10-3, ( 1. 739 ± 0. 044 ) × 10-3 mm2/s, respectively, which were statistically significant (P ＜0. 01 ). When b =200,400,600,800,1000 s/mm2, the differences of ADC values among viable tumor, granulation tissue, necrosis,normal liver tissue were also statistically significant ( P ＜0. 01 ). Conclusion The rabbit liver VX2 tumor models and 3.0 T MR DWI are important tools in the basic and clinical researches of radiofrequency ablation.

ranches of portal vein were found in 3 cases. Conclusion The multi-slice spiral CT findings of eosinophilie hepatic infiltration are relatively specific, and three-phase dynamic CT studies can be a valuable tool for the diagnosis of this disease.

Objective To explore the reproducibility of normal hepatic MRS at 3.0T. Methods The hepatic proton MRS was performed with GE Signa Excite HD 3.0T system and eight-channel torso phased-array coils using PRESS sequence. Thirty-one healthy individuals were enrolled in this study. Liver spectra were collected with TR of 1500 ms, TE of 30 ms, ROI of 2 cm×2 cm×2 cm, NSA of 64 times. The outcomes were statistically analyzed with Wilcoxon signed ranks test and Spearman correlation test.Results There was no significant difference of signal to noise ratio (Z=-0.535,P=0.593), baseline stability (Z=-0.333, P=0.739), linewidth of automatic shimming (Z=-0.305, P=0.761), water suppression (Z=-1.232, P=0.218), height of lipid peak (Z=-0.558,P=0.557), area under the lipid peak (Z=-1.195,P=0.232), height of water peak (Z=-0.647,P=0.518) and area under the warter peak (Z=-0.118, P=0.906) between first examination and second examination. Correlation coefficient of the former and the later measurements of lipid area and water area were 0.784 (P<0.001) and 0.799 (P<0.001), respectively.Conclusion The reproducibility is good for in vivo liver proton MRS at 3.0T.

Objective To evaluate treatment effect of nodal lymphoma by using multiple b value diffusion-weighted MRI based on intravoxel incoherent motion (IVIM) model. Methods From November 2012 to November 2013, 22 patients with pathology confirmed lymphoma in Guangdong General Hospital were chosen. Patients were examined on a 1.5 T MR scanner with plain MRI scan and multiple b value diffusion-weighted MRI scan before and after cycle two of chemotherapy. According to chemotherapy response which evaluated after cycle 2 of chemotherapy, lymphoma nodes were divided into four groups:complete response (CR), partial response (PR), stable disease (SD), progressive disease (PD). Kruskal-Wallis H test was used to compare prechemotherapy D value, f value among CR, PR, SD groups. Nemenyi test was used to compare prechemotherapy D value between the two of CR, PR, SD groups. One-way ANOVA was used to compare D*value among CR, PR, SD groups. Paired-sample t test was used to compare D, f, D*value between before and after chemotherapy in PR group. CR and PR group were ascribed to curative group, and SD group ascribed to poor response group. ROC curve was used to evaluate the predictive efficiency of parameters derived from IVIM. Results Twenty-two lymphoma patients were scanned before chemotherapy and 21 patients were scanned after cycle 2 of chemotherapy. There were 49 lesions in CR group, 17 lesions in PR group, 8 lesions in SD group and no lesions in PD group. Prechemotherapy D value of CR, PR, SD group were (0.63±0.26)×10-3, (0.57±0.10)×10-3,(0.42±0.04)×10-3 mm2/s, respectively. There was significant difference among the three groups (H=12.944,P=0.002). There was no statistically difference of prechemotherapy D value between CR and PR group (χ2=0.072,P=0.965). Prechemotherapy D value was lower in SD group than that in CR group (χ2=12.090,P=0.002) and PR group (χ2=10.684,P=0.005). There was no statistically difference of prechemotherapy f value among CR, PR, SD groups (χ2=2.312,P=0.315) or D*value (F=0.535,P=0.588). D value significantly increased after chemotherapy in PR group [(1.03±0.37)× 10-3 vs.(0.63 ± 0.26)× 10-3 mm2/s, t=-4.781, P=0.001]. f value significantly increased after chemotherapy in PR group [(9.39 ± 4.52)% vs.(6.44 ± 3.25)%, t=2.294, P=0.036]. D* value slightly increased after chemotherapy but with no statistical difference in PR group [(99.72 ± 42.12)× 10-3 vs.(90.37 ± 45.33)× 10-3 mm2/s, t=-0.579, P=0.570]. When a D value of 0.48 × 10-3 mm2/s was used as the threshold value for predicting chemotherapy response, the best results were obtained with sensitivity of 100.00%and specificity of 75.76%.Conclusions Prechemotherapy D value can predict chemotherapy response and D value can monitor chemotherapy response in lymphoma.

Objective To analyze the complications of total proctocolectomy with ileal pouch-anal anastomosis (TPC-IPAA) in treatment of severe or refractory ulcerative colitis (UC).Methods The retrospective cross-sectional study was conducted.The clinical data of 67 patients with severe or refractory UC who underwent TPC-IPAA in the Xinhua Hospital Affiliated to Shanghai Jiaotong University from February 2008 to October 2015 were collected.All the patients received open and laparoscopy-assisted TPC-IPAA,and two-stage or three-stage surgery was performed according to the patients' conditions.Observation indicators:(1) treatment and follow-up situations,(2) short-term complications after TPC-IPAA,(3) long-term complications after TPC-IPAA.The follow-up using telephone interview and outpatient examination was performed to detect the quality of postoperative life in patients and occurrence of complications up to July 2016.Measurement data with skewed distribution were described as M (range).The comparison of quality of pre-and post-operative life in patients was done using the paired t test.Results (1) Treatment and follow-up situations:all the 67 patients received successful surgery,including 45 with two-stage surgery and 22 with three-stage surgery.Thirty-seven patients underwent open surgery and 30 underwent laparoscopic surgery.The average frequency of postoperative daily defecation,average scores of quality of pre-and post-operative lifes were 5.6,0.47 and 0.67,respectively,with a statistically significant difference between preoperative indicators and postoperative indicators (t =-4.80,P ＜ 0.05).All the 67 patients were followed up for a median time of 4.6 years (range,1.0-8.4 years).(2) Short-term complications after TPC-IPAA:Of 67 patients,10 had short-term complications (some patients with multiple complications).One patient was complicated with presacral abscess secondary to sinus formation and then was cured by topical incision of sinus under colonoscopy.Five patients were complicated with anastomotic site-related complications of TPCIPAA,and 1 with pouch-anal anastomotic fistula combined with presacral abscess underwent drainage with ileostomy and didn't undergo stoma reversion of ileum.Two patients with fistula at the top of pouch were improved by surgery and repair.Of 2 patients with pouch-vagina fistula,1 underwent resection of pouch stump-vagina fistula and then were cured,and the space between pouch stump and posterior fornix was filled with a free greater omentum flap and temporary ileal bypass was simultaneously conducted.The other patient received twice transanal vaginal fistula repairs with advancement flap,and unclosed fistula was confirmed by angiography,with a clinical symptomatic relief.Eight patients with wound infection received actively dressing change after discharge,and no wound dehiscence was occurred.(3) Long-term complications after TPC-IPAA:28 of 67 patients had long-term complications.Twelve patients with intestinal obstruction underwent conservative treatments of gastrointestinal decompression,anti-inflammatory with corticosteroid and anti-infection with antibiotic,without the occurrence of severe intestinal perforation and prognosis needing surgical intervention,including 9 undergoing open TPC-IPAA and 3 undergoing laparoscopic TPC-IPAA.Thirteen patients with postoperative pouchitis received the conservative treatment of mesalazine.Three patients with failed pouch underwent small intestine permanent colostomy,including 2 with secondary pouch Crohn's disease and 1 with severe pouchitis.Conclusions TPC-IPAA is safe and effective in treatment of UC,with a lower incidence of complications.Anastomotic site-related complication of TPC-IPAA is the main short-term complication.And in the long-term complications,pouchitis is the most,followed it is intestine obstruction.

Objective Pulmonary hypertension (PH) was an independent predictor of mortality and new onset cardiovascular events in maintenance hemodialysis (MHD) patients. Recent studies revealed PH complicated by pericardial effusion (PE) increased mortality in non-CKD (chronic kidney disease) population. No such evidence existed in MHD patients. Methods We enrolled 108 MHD patients with diagnosed PH by echocardiography (61 with PE) between 2009 and 2011. All patients had been followed-up for 2 years. The endpoints were all-cause mor-tality, cardiovascular (CV) mortality and new onset CV events. Results The mean age was (60.2 ± 14.1) years, 55.6% were males and SPAP was (53.0 ± 15.4) mmHg. 12.0% were severe PH and 1.9% were moderate-to-severe PE. The overall mortality, cardiovascular mortality and new on-set cardiovascular events in PE and non-PE group were 34.4% vs. 21.3%、 23.0% vs. 12.8% and 54.1% vs. 42.6%, respectively (P > 0.05). Kaplan-Meier curve showed there was no difference on all-cause mortality , CV mortality nor new-onset CV events between PE and non-PE group (Log Rank P > 0.05). Conclusions Compared with patients without PE, the presence of PE in patients with PH did not increase the mortality and worsen the cardiovascular outcome in MHD patients.