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.
Objective To investigate the value of MRI on the preoperative diagnosis for breast invasive ductal carcinoma combined with histopathology. Methods Seventy-five patients with breast invasive ductal carcinoma confirmed with surgery and pathology were reviewed， which were treated in our hospital from Jan to Jun in 2012. The data of MRI before operation were retrospectively analyzed. Results The morphological classification of lesions was mass in 54 cases， micronodular in 21 cases， and cystoid solid in 0 case， respectively. The shape of neoplasm was circular in 3 cases， ovoid in 9 cases， and irregular in 63 cases， respectively. The edge of lesions was irregular in 66 cases，regular in 9 cases， and slightest lobulated in 56 cases， respectively. There was 1 case within the tumor calcification and lymph node metastasis in 18 cases. The MRI features of the T1WI were low signal intensity in 65 cases， signal intensity similar in 10 cases， and the T2WI were low signal intensity in 3 cases and mixed slightly high signals in 72 cases. After enhancement， the tumor had homogeneous enhancement in 64 cases， heterogeneous enhancement in 11 cases. Conclusion The analysis of MRI characteristic features of invasive ductal carcinoma can provid b evidence of imaging for clinical diagnosis of breast invasive ductal carcinoma.
【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.
Magnetic resonance imaging(MRI) can obtain multi-modal images with different contrast, which provides rich information for clinical diagnosis. However, some contrast images are not scanned or the quality of the acquired images cannot meet the diagnostic requirements due to the difficulty of patient's cooperation or the limitation of scanning conditions. Image synthesis techniques have become a method to compensate for such image deficiencies. In recent years, deep learning has been widely used in the field of MRI synthesis. In this paper, a synthesis network based on multi-modal fusion is proposed, which firstly uses a feature encoder to encode the features of multiple unimodal images separately, and then fuses the features of different modal images through a feature fusion module, and finally generates the target modal image. The similarity measure between the target image and the predicted image in the network is improved by introducing a dynamic weighted combined loss function based on the spatial domain and K-space domain. After experimental validation and quantitative comparison, the multi-modal fusion deep learning network proposed in this paper can effectively synthesize high-quality MRI fluid-attenuated inversion recovery (FLAIR) images. In summary, the method proposed in this paper can reduce MRI scanning time of the patient, as well as solve the clinical problem of missing FLAIR images or image quality that is difficult to meet diagnostic requirements.
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.
ObjectiveTo investigate the role of amygdala volume index(AVI) in surgcial evaluation in patients with mesial temporal lobe epilepsy (mTLE), including clinical features, etiologies and surgical outcome. MethodsThirty six patients were diagnosed as mTLE after surgical evaluation including clinical manifestations, video-electroencephalogram (VEEG) and magnetic resonance imaging (MRI) at the Second Affiliated Hospital of Zhejiang University between March 2013 and March 2016. Bilateral amygdala AVI was then calculated from amygdala volumes on MRI, which were measured with region of interest (ROI) analysis. All patients were treated surgically. Etiologies of mTLE were further confirmed by the histopathology of the resected tissue. ResultsAmong the 35 patients, there is a strong correlation between AVI on the lesion side and age of onset (R =-0.389, P = 0.019) as well as age of surgery (R =-0.357, P = 0.032). No obvious relation can be seen between AVI and gender, history of febrile convulsion, duration of epilepsy, secondary generalized seizure, side of lesion, presurgical seizure frequency and electrode implantation. There is no significant difference in AVI among the five etiologies. At follow-up, thirty patients (80.5%) reached seizure-free, AVI on the lesion side is nota predictor of surgical failure (P > 0.05). ConclusionAVI plays a role in etiology evaluation in patients with mesial temporal lobe epilepsy. Moreover, a larger AVI on the lesion side is correlated with an earlier age of onset. There is limited value of amygdala volume insurgical outcome prediction of patients with mTLE.
Objective To investigate the value of MR diffusion-weighted imaging (DWI) in differentiating pancreatic carcinoma from chronic focal pancreatitis on 3.0 T MR system. Methods Thirteen patients with proved pancreatic carcinoma, 7 patients with confirmed chronic focal pancreatitis, and 14 healthy volunteers, were included in this study. MR examination including the routine abdomen scanning protocol and DWI was performed for both patients and volunteers. The SE-EPI sequence and ASSET technique were used for DWI. The b values of 400, 600, 800 and 1 000 s/mm2 were selected to acquire the DWI. The corresponding apparent diffusion coefficient (ADC) values were measured in each designated region of interest and statistically analyzed. Results ①DWI of the healthy volunteers showed intermediate signals of pancreas. ②DWI of pancreatic tumor masses showed homogenous high signal intensity relative to the surrounding pancreatic tissue with clear boundary. Under different b values, the tumor ADC values were (1.63±0.235)×10-3 mm2/s, (1.42±0.126)×10-3mm2 /s, (1.36±0.170)×10-3 mm2 /s and (1.26±0.178)×10-3 mm2 /s respectively, which were significantly lower than those of non-tumor region 〔(2.11±0.444)×10-3 mm2 /s, (1.83±0.230)×10-3 mm2 /s, (1.81±0.426)×10-3 mm2 /s, (1.60±0.230)×10-3 mm2 /s〕 and of the normal pancreas 〔(1.85±0.350)×10-3 mm2 /s, (1.69±0.290)×10-3 mm2 /s, (1.67±0.268)×10-3 mm2 /s, (1.42±0.221)×10-3 mm2 /s〕， P＜0.05. ③DWI of chronic focal pancreatitis showed inhomogeneous slightly hyper-intense signal with blurring borders. Under different b values, the ADC values of the inflammatory masses of chronic pancreatitis were (169±0.150)×10-3 mm2 /s, (1.56±0.119)×10-3 mm2 /s, (1.59±0.172)×10-3 mm2/s and (1.35±0.080)×10-3 mm2 /s respectively, which were higher than those of pancreatic carcinoma. When b value was set to 800 s/mm2 , the difference in ADC values between pancreatic carcinoma and chronic focal pancreatitis was statistically significant (P＜0.05). Conclusion MR DWI can clearly depict the tumor mass of pancreatic carcinoma. In addition, the measurement of ADC values can provide useful information for the differential diagnosis between pancreatic carcinoma and chronic focal pancreatitis.
ObjectivesTo investigate the diagnostic value of different diffusion-weighted MRI (DWI) models between two Gaussian DWI models including mono-exponential and bi-exponential, and the non-Gaussian kurtosis model in poorly differentiated pancreatic ductal adenocarcinoma.MethodsSubjects comprised 52 patients with poorly differentiated pancreatic ductal adenocarcinoma which had been confirmed by surgery. All patients underwent DWI (1.5T, multi-b values: 0, 50, 100, 150, 200, 500, 800, 1000, 1 500, 2 000s/mm2). Mean values of DWI-derived metrics ADCstandard, ADCslow, ADCfast, f, MD, MK and ADCstandard were calculated from regions of interest in all tumours and non-tumorous parenchyma and compared. ANOVA and Mann Whitney U test was used to compare the MRI paremeters. ROC was used to evaluate the diagnostic efficiency.ResultsMean ADCstandard, ADCfast, f and MK values showed significant differences between tumours and non-tumorous parenchyma (P<0.05). AUC for ADCstandard, MD, ADCfast and f were 0.705, 0.665, 0.648, 0.614, respectively. The ROC curve integrated with ADCstandard and MD had better diagnostic efficiency (AUC was about 0.754).ConclusionsADCstandard, ADCfast, f and MK values can differentiate tumours from non-tumorous parenchyma. The combination of Gaussion distribution model and non-Gaussion distribution model has the potential to increase the diagnostic accuracy of DWI in patients with pancreatic ductal adenocarcinoma.
Magnetic resonance imaging (MRI) is an important medical imaging method, whose major limitation is its long scan time due to the imaging mechanism, increasing patients’ cost and waiting time for the examination. Currently, parallel imaging (PI) and compress sensing (CS) together with other reconstruction technologies have been proposed to accelerate image acquisition. However, the image quality of PI and CS depends on the image reconstruction algorithms, which is far from satisfying in respect to both the image quality and the reconstruction speed. In recent years, image reconstruction based on generative adversarial network (GAN) has become a research hotspot in the field of magnetic resonance imaging because of its excellent performance. In this review, we summarized the recent development of application of GAN in MRI reconstruction in both single- and multi-modality acceleration, hoping to provide a useful reference for interested researchers. In addition, we analyzed the characteristics and limitations of existing technologies and forecasted some development trends in this field.
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.