Objective To evaluate the features and visualization of venous arcades of the pancreatic head (VAPH) using 16-slice CT with different techniques.Methods Portal-phase CT scanning with 16-slice CT was performed in 40 cases.The visualized rate of VAPH with axial images,thin slice maximum intensity projection(TSMIP) and volume rendering(VR) was assessed.Results With axial images,TSMIP and VR,the visualized rate of right gastro-epiploic vein and gastro-colic vein were all 100% and 80% respectively;while for right colic superior vein was 100%,87.5% and 80%;pancreaticoduodenal posterior-superior vein was 92.5%,65% and 40%;pancreaticoduodenal anterior-superior vein was 92.5%,62.5% and 45% respectively.Conclusion VAPH can be showed definitely using 16-slice CT in combination of axial images,TSMIP and VR images.

PurposeTo prospectively investigate the effect of gadolinium contrast media on the quality of intravoxel incoherent motion (IVIM) MRI images and the quantification of corresponding parameters for abdominal solid organs, and to explore the appropriate time for abdominal IVIM scan.Materials and MethodsTwenty patients underwent the same abdominal IVIM scan before and after gadolinium contrast administration. The signal-to-noise ratio (SNR) of liver, spleen, pancreas and kidneys were measured on diffusion-weighted imaging (DWI) images at b=50 s/mm2, 300 s/mm2 and 800 s/mm2. SNR and contrast-to-noise ratio (CNR) of hepatocellular carcinoma (HCC) (n=16) were also calculated. Apparent diffusion coefficient (ADC) value and IVIM parameters including pure diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f) of liver, spleen, kidneys parenchyma and HCC were measured and compared. ResultsSNR of liver on post-contrast DWI at b=50 s/mm2 were significantly lower than that of pre-contrast (t=2.397,P<0.05). CNR of HCC increased significantly on b=300 s/mm2 DWI images after contrast (t=-3.380,P<0.01). SNR of kidneys on DWI of any b value decreased after contrast administration (Z=-2.675--2.201,P<0.05). SNR of spleen, pancreas and HCC were not statistically different between pre-contrast and post-contrast images (t orZ=-1.324-1.104,P>0.05). As for IVIM parameters, only ADC and D values of kidneys demonstrated a significant reduction after contrast (ADC:t=3.569,P<0.01; D:Z=-3.053,P<0.01). No significant differences were detected for all parameters of liver, spleen and HCC between pre-contrast and post-contrast images (t=-1.102-1.689,P>0.05). ConclusionAdministration of gadolinium contrast media may result in decrease of SNR of liver on low b value DWI and SNR of kidneys at any b value, but it increases CNR of hepatic lesions on medium b value DWI. Administration of gadolinium contrast media does not make a significant effect on SNR of spleen, pancreas and hepatic lesions. Furthermore, ADC and D values of kidneys decrease after administration of gadolinium contrast media. There is no significant influence of contrast medium on DWI and IVIM parameters of liver, hepatic lesions and spleen.

Objective To investigate the CT and MRI features of intraductal papillary neoplasm of the bile duct (IPNB).Methods Thirty eight patients with IPNB finally diagnosed by puncture biopsy or surgery were enrolled in this study.All the CT or MRI data were investigated retrospectively.Twenty one patients underwent CT examinations,17 patients underwent MRI examinations.The features of IPNB including the distribution features of the nodules or masses,CT and MRI features of cholangiectasis,mucus were analyzed.The accuracy differences of CT and MRI for the preoperatively diagnosing mucus and tumor growing along mucous were compared by nonparametric test.Results The lesions (including 5 patients with solitary lesions and 19 patients with multiple lesions) were located in intrahepatic bile duct in 24 patients,3 patients occurred simultaneously in intrahepatic and portal bile duct,2 lesions occurred in portal bile duct,8 lesions occurred in common bile duct,the lesions of 1 patient occurred simultaneously in common bile duct,cystic duct and gallbladder.Seventeen and 11 patients appeared nodules locating in dilated bile duct on CT and MRI,respectively.Four and 5 patients appeared cystic lesions with multiple nodules of the liver on CT and MRI,respectively.Higher contrast enhancement on CT and MRI in arterial phase than that in portal vein and equilibrium phase were observed in 18 and 12 patients,respectively.Excluding the patients undergoing puncture,CT was better than MRI in evaluating whether the mucus was present,with the accuracies of 30.0％ (6/20) and 6.3％ (1/16) for CT and M RI,respectively (Z =2.58,P ＜ 0.05).CT was worse than MRI in preoperatively evaluating the features of tumor growing along mucous,with the accuracies of 77.8％ (14/18) and 92.6％ (13/14) for CT and MRI,respectively (Z =4.23,P ＜ 0.01).Conclusion IPNB had the features of growing along mucous of the bile duct,nodule or mass in dilated bile duct and other features,CT and MRI are important in diagnosing the IPNB.

Objective:To investigate the current funding landscape of medical artificial intelligence (AI) projects in National Natural Science Foundation of China (NSFC) from 2015 to 2019.Methods:From 2015 to 2019, AI-related projects in NSFC Medical Science Department were collected. Comprehensive analysis was performed in the projects information including year, title, supporting institution, fund type, research findings, etc.Results:NSFC has funded a total of 278 projects related to artificial intelligence, with the total funding amount of 139 million yuan. The number of projects and the funding amount were increasing year by year. Among these, 90% (249/278) were general programs and young scientist funds; 53% (148/278) of the projects were regionally distributed in Beijing, Shanghai and Guangdong; 66% (184/278) of the projects were imaging-related researches; the projects mainly focused on diseases with high incidence in China, including neoplastic diseases, cardiovascular and nervous system diseases.Conclusion:The AI-related projects funded by NSFC are characterized by rapid growth in number and fund amounts, wide coverage of disciplines, and diverse types of research diseases. However, the unbalanced distribution of regions, research fields, and supporting institutions demands more attention in future.

Objective To investigate the feasibility of magnetic resonance diffusion-weighted intravoxel incoherent motion (DW-IVIM)imaging and its reproducibility in normal liver.Methods Thirty-five young healthy volunteers underwent liver DW-IVIM ex-amination twice on a 1 .5 Tesla Philips MR scanner.Parameter maps of D,D* and f were generated by using a manufacturer-sup-plied software.Six Region-of-interests (ROIs)(3 ROIs in left and right liver lobe,respectively)were drawn on three consecutive middle slices,respectively.The average values of D,D* and f were measured and compared between the left and right liver lobe. The reproducibility of D,D* and f measurement were assessed with Bland-Altman method.Results The values of D,D* and f of left liver lobe [D(×10-3 mm2/s):1.250±0.210,D*(×10-3 mm2/s):101.906±15.063 ,f(%):22.954±5.268]were statistically higher than those of right liver lobe[D(×10-3 mm2/s):1.039±0.124,D*(×10-3 mm2/s):100.127±20.757,f(%),18.317± 3.671](D,f,P<0.001,D*,P<0.232-0.605),however ,their reproducibility of left liver lobe [limit of agreement(LOA):22.55%,51.05%,39.3%,respectively]were lower than those of right liver lobe (LOA:20.3%,39.25%,33.9%).The D values had the best reproducibility in both the left and right liver lobe.Conclusion The liver DW-IVIM is feasible.The values of D,D*and f in left liver lobe were higher that those in right liver lobe but with worse reproducibility of measurement.The D value was most reproducible in both liver lobes.

Purpose To investigate the effect of two different 1.5T MRI scanners on the apparent diffusion coefficient (ADC) measurement and its reproducibility in diffusion weighted imaging (DWI) of the liver. Materials and Methods Two groups of volunteers (33 people in each group) underwent liver DWI examination twice by using the same DWI sequence with b value of 0 and 800 s/mm2 on different MRI scanners (1.5T Siemens Espree and 1.5T Philips Achieva). On ADC maps, two region of interests were placed on three central slices of the left and right liver lobes, respectively. The ADC measurements of six region of interests on left and right liver lobes were averaged to represent the mean ADC values of the left and right liver lobe, respectively. The reproducibility of the ADC measurements was assessed by Bland-Altman method. Results The ADC values of the left and right liver lobes measured on Siemens MRI scanner were significantly higher than those on Philips MRI scanner (t=2.045-2.713, P<0.05); on both scanners, the ADC values of the left liver lobe were significantly higher than those of the right liver lobe (t=-10.561--7.263, P<0.001). The Bland-Altman results showed that the reproducibility of ADC measurement was similar on both MRI scanners, and both displayed higher reproducibility of right liver lobe than that of left liver lobe (on Siemens MRI scanner: the agreement were 16.65% and 7.55% for the left and right liver lobe, respectively;and on Philips MRI scanner:16.30%and 7.85%, respectively. Conclusion Different MRI scanners may have influence on ADC values, but does not affect its reproducibility. Therefore, when ADC values obtained on different MR scanners are compared in clinical analysis, this influence should be considered.

Objective To evaluate the role of contrast enhanced CT (CECT) scanning in the diagnosis and treatment planning of some rare liver tumors. Methods We retrospectively reviewed the CECT imaging features of 10 cases with rare tumors of the liver proved by surgical pathology in 8 cases or by liver biopsy in 2 cases, with correlation of relevant clinical manifestations, laboratory results and surgical findings. Results Three cases were histopathologically proved to be benign, and 7 cases were malignant. On CT images, the liver lesions were mixed cystic solid in 5 cases, totally solid in the other 5. Eight cases demonstrated heterogeneous enhancement, while 2 cases of liver lymphoma had no enhancement. The anatomic relationship of tumors to intrahepatic vasculature, the compression and infiltration of neighboring abdominal structures were accurately delineated by CT as compared with findings at operation. Clinical manifestations and laboratory findings were not useful for the qualitative diagnosis of rare liver tumors, except for hepatocellular carcinoma. Conclusion CECT is very useful for the detection of rare liver tumors and the fine depiction of local extent of these tumors. When correlated with clinical and laboratory information, it helps to differentiate rare liver tumors from hepatocellular carcinoma. But its role in the characterization of rare liver tumors is limited.

Objective To characterize the clinical factors which influence water suppression and auto-shimming line width for liver 3.0 T 1H-MRS.Methods Fifty-seven cases with liver 1H-MR spectroscopy(1H-MRS) were retrospectively studied, including chronic type B hepatitis (n=5), fatty liver (n=14), chronic type B hepatitis combining fatty liver (n=3) and normal situation (n=35).Independent t test was used to characterize the difference of general condition (height, weight, body mass index etc.) between different water suppression effect groups and between different shimming effect groups.Using Chi-square test to analyze whether water suppression rate and auto-shimming line width between fatty liver groups and non-fatty liver exist significance difference .Results By comparing WS ≥90% (n=47)group with WS < 90% (n=10) group, the former showed smaller average height[(164.7±8.0) and (170.5±3.7) cm respectively], weight[(61.8±10.4) and (73.4±5.4) kg respectively], BMI [(22.7±3.2) and (25.2±1.3)kg/m2 respectively]and LW[(17.7±3.7)and(24.6±6.3) Hz respectively]than the latter (t=-3.488,-3.415,-4.002 and-3.327, P < 0.05).By comparing LW 20 Hz (n=41) group with LW 20 Hz (n=16) group, the former showed better water suppression rate [(93.0±2.7)% and (86.1±8.5)% respectively]than the latter(t=3.213,P <0.05), whereas larger weight[(62.2±11.6) and (68.1±6.1)kg respectively]and BMI[(22.8±3.4) and (24.2±1.9)kg/m2 respectively](t=-2.516,-2.024,P <0.05).LW≤20 Hz in the fatty liver and non-fatty liver group was 7/17 and 34/40, respectively (X2=11.347, P < 0.05).WS < 90% in the fatty liver and non-fatty liver group was 10/17 and 0/44, respectively (X2=28.536, P < 0.05) .Conclusion Hepatic steatosis exerts an adverse effect in water suppression and shimming.

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 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.