Department of Radiology, Changzhou Second People's Hospital, Changzhou, China.
Graduate College, Dalian Medical University, Dalian, China.
J Magn Reson Imaging. 2021 Sep;54(3):751-760. doi: 10.1002/jmri.27604. Epub 2021 Mar 21.
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.
FIELD STRENGTH/SEQUENCE: 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 (K , K , and V ). 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 K and V gradually increased (all P < 0.05). The degrees of change for f and V 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[K ] = -0.522, 0.500, r[V ] = -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 [K 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 K and V (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 K and V (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.
体素内不相干运动（IVIM）可以提供关于水扩散和灌注的定量信息，可用于评估肝损伤，但尚未在肠缺血再灌注（IIR）引起的肝损伤中进行研究。动态对比增强（DCE）磁共振成像（MRI）可以提供灌注数据，但尚不清楚它是否可以为评估 IIR 引起的肝损伤提供有用的信息。
研究 IVIM 和 DCE-MRI 是否能检测到早期 IIR 引起的肝变化，并评估 IVIM 和 DCE 衍生参数与生化指标和组织学评分之间的关系。
前瞻性临床前研究。
42 只雄性 Sprague-Dawley 大鼠。
磁场强度/序列：IVIM-扩散加权成像（DWI）采用扩散加权回波平面成像序列和 DCE-MRI 采用快速扰相梯度回波序列，在 3.0T 下进行。
所有大鼠随机分为对照组（Sham）、单纯缺血组、缺血再灌注（IR）组（IR1h、IR2h、IR3h 和 IR4h），在由 IIR 引起的继发性肝损伤模型中。夹闭肠系膜上动脉 60 分钟后再移除血管夹。使用高级工作站（AW）4.6 计算 IVIM 的成像参数（表观扩散系数 [ADC]、真实扩散系数 [D]、与灌注相关的扩散 [D ]和体积分数 [f]）。使用 OmniKinetics（OK）软件计算 DCE 成像参数（K 、K 、和 V ）。采用自动生化分析仪分析丙氨酸氨基转移酶（ALT）和天冬氨酸氨基转移酶（AST）。超氧化物歧化酶（SOD）活性采用硝基四氮唑蓝法测定。丙二醛（MDA）含量采用硫代巴比妥酸比色法测定。苏木精和伊红染色进行组织病理学检查。
采用单因素方差分析（ANOVA）和 Bonferroni 事后检验分析不同组之间的成像参数和生化指标。采用 Pearson 相关分析确定成像参数与生化指标或组织学评分之间的相关性。
ALT 和 MDA 在 IR4h 时达到峰值，而 SOD 在 IR4h 时达到最低水平（均 P<0.05）。随着再灌注的继续，ADC、D、D 和 f 逐渐降低，K 和 V 逐渐增加（均 P<0.05）。在 IR1h 时，f 和 V 的变化程度大于其他成像参数（均 P<0.05）。所有组的成像参数与 SOD 和 MDA 之间均具有良好的相关性（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[K ] = -0.522，0.500；r[V ] = -0.590，0.665；均 P<0.05）。然而，IR 组的成像参数与 SOD 和 MDA 之间的相关性较差或无相关性（P [K 和 MDA] = 0.050，P [D 和 SOD] = 0.125，P [其余成像参数] < 0.05）。所有组的组织学评分与 K 和 V 呈正相关（r = 0.775，0.874；均 P<0.05），与 ADC、D、f 和 D 呈负相关（r = -0.739，-0.821，-0.868，-0.841；均 P<0.05）。对于 IR 组，组织学评分与 K 和 V 呈正相关（r = 0.747，0.802；均 P<0.05），与 ADC、D、f 和 D 呈负相关（r = -0.567，-0.712，-0.715，-0.779；均 P<0.05）。
IVIM 和 DCE-MRI 的联合应用具有作为监测 IIR 引起的肝组织病理学变化的成像工具的潜力。
1 技术功效分期：2。
