【Abstract】ObjectiveTo investigate the relationship of magnetic resonance diffusion-weighted imaging (DWI) to histology in the patients of chronic viral hepatitis. MethodsThirty-five patients of chronic viral hepatitis who received liver biopsy and 10 healthy volunteers were included in this study. All of them underwent DWI on a 3.0T MRI device. Apparent diffusion coefficient (ADC) of the liver were measured respectively when b value were set as 100, 400, 600 and 800 s/mm2. Biopsy specimens were scored for fibrosis and necroinflammation according to the Knodell histology activity index (HAI). ResultsWhen b value was set as 800 s/mm2, statistical difference was showed between the fibrosis group and the nonfibrosis group, statistical difference was also shown among the different degrees of necroinflammation and fibrosis. ConclusionDWI is a valuable method for grading and staging of chronic viral hepatitis.
Objective To evaluate the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) in obstructive jaundice. Methods Forty eight consecutive patients with obstructive jaundice were examined by MRCP, all results were testified during and /or after operation. Results Different causes of obstruction had their own characteristic manifestations. Level of obstruction was accurate in 100%, the accuracy in distinguishing obstructive causes was 93.8%. Conclusion MRCP is quite effective, safe and reliable in diagnosis of obstructive jaundice.
Objective To evaluate the values of magnetic resonance imaging (MRI) in the diagnosis of acetabular labral tears (ALT) by meta-analysis. Methods The studies concerning the diagnosis of ALT tears by using MRI from January 1990 to October 2016 were searched in the databases such as CBM, VIP, WanFang Data, CNKI, PubMed, EMbase, The Cochrane Library and Web of Science. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies by using the QUADAS-2 tool. Then, meta-analysis was performed by using Stata 12.0 software. The pooled sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (–LR) and the diagnostic odds ratio (DOR) were calculated, and the summary receiver operating characteristic curve (SROC) was drawn and the area under the carve was calculated. Results A total of 25 studies from 21 articles were included, involving 1 123 hips from 1 099 patients. The results of meta-analysis showed that, the pooled Sen, Spe, +LR, –LR, DOR and area under SROC curve of MRI for diagnosing ALT were 0.66 (95% CI 0.38 to 0.86), 0.72 (95% CI 0.47 to 0.89), 2.37 (95% CI 1.18 to 4.67), 0.48 (95% CI 0.25 to 0.92), 4.97 (95% CI 1.60 to 15.47), 0.75 (95% CI 0.71 to 0.79). The pooled Sen, Spe, +LR, –LR, DOR and area under SROC curve of MRA for diagnosing ALT were 0.86 (95% CI 0.80 to 0.90), 0.71 (95% CI 0.55 to 0.83), 2.91 (95% CI 1.77 to 4.80), 0.20 (95% CI 0.13 to 0.32), 14.44 (95% CI 5.80 to 35.95), 0.87 (95% CI 0.84 to 0.90), respectively. Conclusion MRI is efficiency diagnostic method for acetabular labral tears.
【Abstract】ObjectiveTo evaluate the value of MR imaging with a contrast-enhanced multi-phasic isotropic volumetric interpolated breath-hold examination (VIBE) in diagnosis of primary liver carcinoma. MethodsThirty-two consecutive patients with surgical-pathologically confirmed 42 foci of primary carcinoma of liver underwent comprehensive MR examination of the upper abdomen, routine two-dimensional (2D) T1WI and T2WI images were acquired before administration of Gd-DTPA for contrast enhancement. Then, contrast-enhanced multi-phasic VIBE was acquired followed by 2D T1WI images. The lesion appearances on hepatic arterial, portal venous and equilibrium phases of VIBE sequence were carefully observed along with delineation of hepatic arterial and portal venous structures. The lesion detection rates and lesion characterization ability were compared among various MR sequences. Results33(78.6%), 30(71.4%), 38(90.5%) and 42(100%) foci were displayed respectively on T2WI, non-enhanced T1WI, enhanced T1WI and enhanced 3D-VIBE images (P＜0.05). The hepatic arterial anatomy of 30 patients （93.8%） and the portal venous structure of 31 patients （96.9%） were clearly depicted on enhanced 3D-VIBE images. Using MIP and MPR reconstruction techniques, the feeding arteries of 14 foci and draining vein of 12 foci were clearly displayed.ConclusionHigh-quality 3D-VIBE images are not only better than 2D images in lesion detection and characterization for primary liver carcinoma, but also able to provide much more information about hepatic vascular anatomy.
Objective To investigate the feasibility of imaging of bone marrow mesenchymal stem cells (BMMSCs) labeled with superparamagnetic iron oxide(SPIO) transplanted into coronary artery in vivo using magnetic resonance imaging (MRI), and the redistribution of the cells into other organs. Methods BMMSCs were isolated, cultured from bone marrow of Chinese mini swine, and double labeled with SPIO and CMDiI(Cell TrackerTM C-7001). The labeled cells were injected into left anterior descending coronary artery through a catheter. The injected cells were detected by using MRI at 1 week,3weeks after transplantation. And different organs were harvested and evaluated the redistribution of transplanted cells through pathology. Results The SPIO labeled BMMSCs injected into coronary artery could be detected through MRI and confirmed by pathology and maintained more than 3 weeks. The SPIO labeled cells could be clearly imaged as signal void lesions in the related artery. The pathology showed that the injected cells could be distributed into the area of related artery, and the cells injected into coronary artery could be found in the lung, spleen, kidney, but scarcely in the liver, the structures of these organs remained normal. Conclusion The SPIO labeled BMMSCs injected into coronary artery can be detected by using MRI, the transplanted cells can be redistributed into the non-targeted organs.
Magnetic resonance (MR) imaging is an important tool for prostate cancer diagnosis, and accurate segmentation of MR prostate regions by computer-aided diagnostic techniques is important for the diagnosis of prostate cancer. In this paper, we propose an improved end-to-end three-dimensional image segmentation network using a deep learning approach to the traditional V-Net network (V-Net) network in order to provide more accurate image segmentation results. Firstly, we fused the soft attention mechanism into the traditional V-Net's jump connection, and combined short jump connection and small convolutional kernel to further improve the network segmentation accuracy. Then the prostate region was segmented using the Prostate MR Image Segmentation 2012 (PROMISE 12) challenge dataset, and the model was evaluated using the dice similarity coefficient (DSC) and Hausdorff distance (HD). The DSC and HD values of the segmented model could reach 0.903 and 3.912 mm, respectively. The experimental results show that the algorithm in this paper can provide more accurate three-dimensional segmentation results, which can accurately and efficiently segment prostate MR images and provide a reliable basis for clinical diagnosis and treatment.
Objective To evaluate the imaging features of pancreatic neuroendocrine carcinoma （PNEC）. Methods The imaging data of 7 patients with PNECs proved by surgery and pathology in West China Hospital of Sichuan University from Jul. 2007 to Dec. 2012 were retrospectively analyzed. The boundary， density， and strengthening features of tumor were observed. Results Seven tumors were found in all patients with 2 in pancreatic head， body， and tail， respectively. There was 1 tumor in pancreatic body and tail too. Five tumors were with unclear boundary. Five tumors had hypodense enhancement and 2 had isodense enhancement. Two cases had distal pancreatic duct dilation. None of them had liver metastases or lymph node involvement. Conclusion PNEC has certain characteristics on imaging. It is difficult to distinguish diagnosis from pancreatic cancer.
ObjectiveTo study the model to predict thymus volume with two-dimensional section diameters among fetuses. MethodsFrom September 2010 to March 2012, 210 singleton pregnant women suspected with fetal abnormality by prenatal ultrasonic testing were confirmed using MRI technology. Three two-dimensional section diameters of thymus were measured and the volume was calculated. No abnormal fetuses regarded as the standard, theoretical normal volume of fetal thymus was calculated. Paired t-test was used to compare the actual thymus volume with its corresponding theoretical normal value, and thus the fetuses were divided into two groups of normal and dysplasia so as to establish predictive model respectively. With two-dimensional section diameters as independent variables and thymus volume as dependent variable, the linear regression model was established. According to the model, the thymus volume was predicted and the error rate was calculated by formula: error rate=(predicted value-actual value) /actual value×100%. The Pearson correlation coefficient of error rate and fetal gestational age was calculated. ResultsThe models of normal and dysplasia groups to predict thymus volume were lnV=0.016d1+0.030d2+0.086d3+5.707+ε (R2=0.510) and lnV=0.048d1+0.036d2+0.016d3+6.011+ε (R2=0.447). The average absolute values of predicted error rate were 4.34% and 5.34% and decreased with fetal gestational age (normal r=-0.264, P=0.007; dysplasia r=-0.182, P=0.060). ConclusionThe prediction effects of above models are not so good and the model accuracy increases with fetal gestational age. Normal fetuses' model of different gestational age should be established to predict thymus volume by conducting large sample size study in the future. The modeling approach has certain practicability and clinical value and can be applied in ultrasonic technique.
Objective To study the MRI features of intracranial solitary fibrous tumor (ISFT). Methods MRI features of 8 patients with ISFT treated between December 2010 and December 2015 were retrospectively analyzed and relavent literatures about its neuroimaging were reviewed. Results All the 8 cases were single solitary fibrous tumor (SFT), among which 4 arose from and beneath the tentorium, 2 in the left cerebellopontine angle, 1 in jugular foramen region and 1 in saddle area. All tumors had clear boundary, 3 were oval or round, 2 were irregular-shaped, 2 were lobulated and 1 was dumb-bell shaped. Tumor size ranged from 35 to 65 mm. On pre-contrast MRI, 5 cases were mixed with hypo to hyperintense signals on (T1 weighted image) T1WI and heterogeneous on (T2 weighted image) T2WI. The rest 3 cases were featured by solid and cystic components; the solid component was hypo to isotense on T1WI and hypointense on T2WI while the cystic areas, which were not enhanced in the postcontrast images, were hypo and hyperintense on T1WI and T2WI, respectively. All the areas with low T2 signal intensity were strongly enhanced after gadolinium administration. Flow-empty actions, peritumoral edema and “dural tail” sign was found in 6, 3 and 0 cases, respectively. All the 3 cystic cases were confirmed as malignant ISFT while the rest 5 were benign. Conclusions MRI manifestation of ISFT has some characteristics. There may exist some correlations between the intratumoral cyst and malignant potential. However, the diagnosis of ISFT remains dependent on histopathology.
ObjectiveTo evaluate the value of magnetic resonance cholangiopancreatography (MRCP) on prevention of the complications in laparoscopic cholecystectomy (LC). MethodsThe clinical data of 1 079 patients underwent LC from January 2006 to June 2010 in this hospital were retrospectively analyzed. According to the use of MRCP or not in the different period, the patients were divided into nonMRCP group (n=523) and MRCP group (n=556). The occurrence of bile duct injuries (BDI) and retained common duct stone (RCDS) were compared between two groups. ResultsConversion to open surgery was performed in 35 cases in nonMRCP group and in 41 cases in MRCP group. The intraoperative and postoperative BDI were found in five patients and RCDS were found in 27 patients in nonMRCP group, and those were not found in patients in MRCP group. The differences of BDI and RCDS of patients were significant between two groups (P=0.026 and P=0.000). In nonMRCP group, 23 of 55 patients were found common bile duct stones by intraoperative cholangiography. Common bile duct stones were found by intraoperative cholangiography other than preoperative MRCP in three patients in MRCP group, while another three patients did not find common bile duct stones by intraoperative cholangiography although preoperative MRCP suggested. By MRCP, double gallbladders were found in one patient, Mirizzi syndrome in eight patients, variant cystic duct in 34 patients, accessory hepatic duct in 28 patients, and complicating common bile duct stones in 27 patients in MRCP group, the diagnostic accuracy of those were 100%, 87.5%, 94.1%, 89.3% and 88.9%, respectively. ConclusionPreoperative MRCP is helpful to prevent BDI and RCDS for the patients with LC.