Intravoxel Incoherent Motion and Dynamic Contrast-Enhanced Magnetic Resonance Imaging to Early Detect Tissue Injury and Microcirculation Alteration in Hepatic Injury Induced by Intestinal Ischemia-Reperfusion in a Rat Model.

Intravoxel incoherent motion (IVIM) can provide quantitative information about water diffusion and perfusion that can be used to evaluate hepatic injury, but it has not been studied in hepatic injury induced by intestinal ischemia-reperfusion (IIR). Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) can provide perfusion data, but it is unclear whether it can provide useful information for assessing hepatic injury induced by IIR. To examine whether IVIM and DCE-MRI can detect early IIR-induced hepatic changes, and to evaluate the relationship between IVIM and DCE-derived parameters and biochemical indicators and histological scores. Prospective pre-clinical study. Forty-two male Sprague-Dawley rats. IVIM-diffusion-weighted imaging (DWI) using diffusion-weighted echo-planar imaging sequence and DCE-MRI using fast spoiled gradient recalled-based sequence at 3.0 T. All rats were randomly divided into the control group (Sham), the simple ischemia group, the ischemia-reperfusion (IR) group (IR1h, IR2h, IR3h, and IR4h) in a model of secondary hepatic injury caused by IIR, and IIR was induced by clamping the superior mesenteric artery for 60 minutes and then removing the vascular clamp. Advanced Workstation (AW) 4.6 was used to calculate the imaging parameters (apparent diffusion coefficient [ADC], true diffusion coefficient [D], perfusion-related diffusion [D* ] and volume fraction [f]) of IVIM. OmniKinetics (OK) software was used to calculate the DCE imaging parameters (Ktrans , Kep , and Ve ). Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed with an automatic biochemical analyzer. Superoxide dismutase (SOD) activity was assessed using the nitro-blue tetrazolium method. Malondialdehyde (MDA) was determined by thiobarbituric acid colorimetry. Histopathology was performed with hematoxylin and eosin staining. One-way analysis of variance (ANOVA) and Bonferroni post-hoc tests were used to analyze the imaging parameters and biochemical indicators among the different groups. Pearson correlation analysis was applied to determine the correlation between imaging parameters and biochemical indicators or histological score. ALT and MDA reached peak levels at IR4h, while SOD reached the minimum level at IR4h (all P < 0.05). ADC, D, D* , and f gradually decreased as reperfusion continued, and Ktrans and Ve gradually increased (all P < 0.05). The degrees of change for f and Ve were greater than those of other imaging parameters at IR1h (all P < 0.05). All groups showed good correlation between imaging parameters and SOD and MDA (r[ADC] = 0.615, -0.666, r[D] = 0.493, -0.612, r[D* ] = 0.607, -0.647, r[f] = 0.637, -0.682, r[Ktrans ] = -0.522, 0.500, r[Ve ] = -0.590, 0.665, respectively; all P < 0.05). However, the IR groups showed poor or no correlation between the imaging parameters and SOD and MDA (P [Ktrans and MDA] = 0.050, P [D and SOD] = 0.125, P [the remaining imaging parameters] < 0.05). All groups showed a positive correlation between histological score and Ktrans and Ve (r = 0.775, 0.874, all P < 0.05), and a negative correlation between histological score and ADC, D, f, and D* (r = -0.739, -0.821, -0.868, -0.841, respectively; all P < 0.05). For the IR groups, there was a positive correlation between histological score and Ktrans and Ve (r = 0.747, 0.802, all P < 0.05), and a negative correlation between histological score and ADC, D, f, and D* (r = -0.567, -0.712, -0.715, -0.779, respectively; all P < 0.05). The combined application of IVIM and DCE-MRI has the potential to be used as an imaging tool for monitoring IIR-induced hepatic histopathology. 1 TECHNICAL EFFICACY STAGE: 2.

Yang J ，Meng M ，Pan C ，Qian L ，Sun Y ，Shi H ，Shen Y ，Dou W ... -  《-》

Intravoxel Incoherent Motion Diffusion-Weighted Imaging for Evaluation of the Cell Density and Angiogenesis of Cirrhosis-Related Nodules in an Experimental Rat Model: Comparison and Correlation With Dynamic Contrast-Enhanced MRI.

Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and dynamic contrast-enhanced MRI (DCE-MRI) are sensitive imaging modalities for detecting liver lesions, but their value in evaluating cirrhosis-related nodules remains unclear. To investigate whether IVIM-DWI and DCE-MRI can differentiate different types of cirrhosis-related nodules, and whether these modalities can monitor changes in cell density and angiogenesis during the malignant transformation of cirrhosis-related nodules in a rat model STUDY TYPE: Prospective. Thirty-five male Sprague-Dawley rats with 106 cirrhosis-related nodules (19 regenerative nodules [RNs], 47 dysplastic nodules [DNs], and 40 hepatocellular carcinomas [HCCs]). IVIM-DWI and DCE sequence at 3.0T MRI. IVIM-DWI parameters (D, D*, f, and apparent diffusion coefficient [ADC]) and DCE-MRI parameters (Ktrans , Kep , and Ve ) were calculated by two radiologists using postprocessing software. The "cell density" and "unpaired arterial ratio" were analyzed with a microscope by two pathologists. MRI parameters were compared among the different types of nodules by one-way analysis of variance or the Kruskal-Wallis test. The Pearson correlation test was used to analyze the correlation of MRI parameters with the pathological types of nodules, cell density, and unpaired arterial ratio. The Ktrans , Kep , and Ve values of HCCs were significantly higher than those of DNs and RNs. D and ADC values were significantly lower in HCCs than in DNs and RNs. There were moderate positive correlations of Ktrans with the pathological types of nodules and the unpaired arterial ratio. Moderate negative correlations were observed among D, ADC, and the pathological types of nodules, between D and cell density, and between ADC and cell density. IVIM-DWI and DCE-MRI are valuable in differentiating different types of cirrhotic-related nodules. D and ADC are correlated with changes in cell density during the malignant transformation of cirrhosis-related nodules, while Ktrans is correlated with increased angiogenesis. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:812-823.

Luo J ，Zhou K ，Zhang B ，Luo N ，Bian J ... -  《-》

Can intravoxel incoherent motion diffusion-weighted imaging characterize the cellular injury and microcirculation alteration in hepatic ischemia-reperfusion injury? An animal study.

To investigate whether intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) can be used to quantitatively analyze the cellular injury and microcirculation alterations in hepatic ischemia-reperfusion injury (HIRI). Thirty-two New Zealand white rabbits were randomly and equally assigned to the sham group, 1-hour, 4-hour, and 12-hour groups according to the reperfusion time after 1 hour of ischemia using a 70% liver ischemia-reperfusion injury model. All the animals underwent IVIM-DWI with 12 b values at 1.5T. The imaging parameters (IVIM parameters and apparent diffusion coefficient [ADC]) among different groups were compared. The correlations between imaging parameters and histological scores, and the ratio of serum aspartate aminotransferase to serum alanine aminotransferase (serum AST/ALT) were analyzed. During the first hour of HIRI, true diffusion coefficient (D) and ADC significantly decreased (P < 0.05), while there was no significant decrease in perfusion fraction (f) (P = 0.708). There was fair to good correlation between histological scores and f (rs  = -0.493 with the sham cases excluded, and -0.682 with all cases, both P < 0.05) and ADC (rs  = -0.479 with the sham cases excluded, and -0.766 with all cases, both P < 0.05). There was no correlation between imaging parameters and serum AST/ALT with the sham cases excluded (P = 0.673 for f, 0.568 for D, 0.403 for ADC), and good correlation between D, ADC, and serum AST/ALT (r = 0.747 and 0.748, both P < 0.001) with all cases. IVIM-DWI can quantitatively characterize an animal model of HIRI, with D and ADC sensitive in early detection of cellular injury, as well as fair to good correlation between f, ADC, and microcirculation alteration. J. Magn. Reson. Imaging 2016;43:1327-1336.

Ye W ，Li J ，Guo C ，Chen S ，Liu YB ，Liu Z ，Wu H ，Wang G ，Liang C ... -  《-》

Perfusion-sensitive parameters of intravoxel incoherent motion MRI in rectal cancer: evaluation of reproducibility and correlation with dynamic contrast-enhanced MRI.

Yang X ，Xiao X ，Lu B ，Chen Y ，Wen Z ，Yu S ... -  《-》

Histogram Analysis Comparison of Monoexponential, Advanced Diffusion-Weighted Imaging, and Dynamic Contrast-Enhanced MRI for Differentiating Borderline From Malignant Epithelial Ovarian Tumors.

The accurate preoperative differentiation between borderline and malignant epithelial ovarian tumors (BEOTs vs. MEOTs) is crucial for determining the proper surgical strategy and improving the patient's postoperative quality of life. Several diffusion and perfusion MRI technologies are valuable for the differentiation; however, which is the best remains unclear. To compare the whole solid-tumor volume histogram analysis of diffusion-weighted imaging (DWI), diffusion kurtosis imaging (DKI), intravoxel incoherent motion (IVIM), and dynamic contrast-enhanced MRI (DCE-MRI) in the differentiation of BEOTs vs. MEOTs and to identify the correlations between the perfusion parameters from IVIM and DCE-MRI. Retrospective. Twenty patients with BEOTs and 42 patients with MEOTs. 1.5T/DWI, DKI, and IVIM models fitting from 13 different b factors and 40 phases DCE-MRI. Histogram metrics were derived from the apparent diffusion coefficient (ADC), diffusion kurtosis (K), diffusion coefficient (Dk), pure diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (f), volume transfer constant (Ktrans ), rate constant (kep ), and extravascular extracellular volume fraction (ve ). The Mann-Whitney U-test and receiver operating characteristic curve were used to determine the best histogram metrics and parameters. Multivariate logistic regression analysis was used to determine the best combined model for each two from the four technologies. Spearman's rank correlation was used to analyze the correlations between the IVIM and DCE-MRI parameters. ADC, D, Dk, and D* were significantly higher in BEOTs than in MEOTs (P < 0.05). K, Ktrans , kep , and ve were significantly lower in BEOTs than in MEOTs (P < 0.05). The 10th percentile of Dk was the most reliable single metric, with an area under the curve (AUC) of 0.921. Dk combined with Ktrans yielded the highest AUC of 0.950. A weak inverse correlation was found between D and Ktrans (r = -0.320, P = 0.025) and between D and kep (r = -0.267, P = 0.037). The 10th percentile of Dk was the most valuable metric and Dk combined with Ktrans had the best performance for differentiating BEOTs from MEOTs. There was no evident link between perfusion-related parameters derived from IVIM and DCE-MRI. 4 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;52:257-268.

He M ，Song Y ，Li H ，Lu J ，Li Y ，Duan S ，Qiang J ... -  《-》