Ren Yan, Chen Lihua, Yuan Yizhong, Xu Jipan, Xia Fangjie, Zhu Jinxia, Shen Wen
Department of Radiology, Tianjin First Central Hospital, Tianjin Institute of Imaging Medicine, Tianjin, China.
Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China.
Front Physiol. 2023 May 22;14:1159741. doi: 10.3389/fphys.2023.1159741. eCollection 2023.
Cold ischemia-reperfusion injury (CIRI) is one of the most serious complications following renal transplantation. The current study investigated the feasibility of Intravoxel Incoherent Motion (IVIM) imaging and blood oxygenation level-dependent (BOLD) in the evaluation of different degrees of renal cold ischemia-reperfusion injury in a rat model. Seventy five rats were randomly divided into three groups (N = 25 for each group): T0: sham-operated group, T2/T4: CIRI groups with different cold ischemia hours (2, 4 h, respectively). The rat model of CIRI group was established by left kidney cold ischemia with right nephrectomy. All the rats received a baseline MRI before the surgery. Five rats in each group were randomly selected to undergo an MRI examination at 1 h, day 1, day 2 and day 5 after CIRI. The IVIM and BOLD parameters were studied in the renal cortex (CO), the outer stripe of the outer medulla (OSOM), and the inner stripe of the outer medulla (ISOM) followed by histological analysis to examine Paller scores, peritubular capillary (PTC) density, apoptosis rate and biochemical indicators to obtain the contents of serum creatinine (Scr), blood urea nitrogen (BUN), superoxide dismutase (SOD) and malondialdehyde (MDA). The D, D*, PF and T2* values in the CIRI groups were lower than those in the sham-operated group at all timepoints (all < 0.05). The prolonged cold ischemia times resulted in gradually lower D, D*, PF and T2* values (all < 0.05). The D and T2* values of cortex and OSOM in Group T0 and T2 returned to the baseline level (all > 0.05) except Group T4. The D* and PF values of cortex, OSOM and ISOM in Group T2 and T4 still remained below the normal levels (all < 0.05) except Group T0. D, D*, PF and T2* values were strongly correlated with histopathological (Paller scores, PTC density and apoptosis rate) and the biochemistry indicators (SOD and MDA) (|r|>0.6, < 0.001). D*, PF and T2* values were moderately to poorly correlated with some biochemistry indicators (Scr and BUN) (|r|<0.5, < 0.05). IVIM and BOLD can serve as noninvasive radiologic markers for monitoring different degrees of renal impairment and recovery after renal CIRI.
冷缺血再灌注损伤（CIRI）是肾移植后最严重的并发症之一。本研究探讨体素内不相干运动（IVIM）成像和血氧水平依赖性功能磁共振成像（BOLD）在大鼠模型中评估不同程度肾冷缺血再灌注损伤的可行性。75只大鼠随机分为三组（每组n = 25）：T0：假手术组，T2/T4：不同冷缺血时间（分别为2、4小时）的CIRI组。通过左肾冷缺血并切除右肾建立CIRI组大鼠模型。所有大鼠在手术前均接受一次基线磁共振成像（MRI）检查。每组随机选取5只大鼠在CIRI后1小时、第1天、第2天和第5天进行MRI检查。研究肾皮质（CO）、肾外髓质外层条纹（OSOM）和肾外髓质内层条纹（ISOM）的IVIM和BOLD参数，随后进行组织学分析以检查帕勒评分、肾小管周围毛细血管（PTC）密度、凋亡率，并检测生化指标以获取血清肌酐（Scr）、血尿素氮（BUN）、超氧化物歧化酶（SOD）和丙二醛（MDA）的含量。在所有时间点，CIRI组的D、D*、PF和T2值均低于假手术组（均P < 0.05）。冷缺血时间延长导致D、D、PF和T2值逐渐降低（均P < 0.05）。除T4组外，T0组和T2组皮质和OSOM的D和T2*值恢复至基线水平（均P > 0.05）。除T0组外，T2组和T4组皮质、OSOM和ISOM的D和PF值仍低于正常水平（均P < 0.05）。D、D*、PF和T2值与组织病理学（帕勒评分、PTC密度和凋亡率）及生化指标（SOD和MDA）密切相关（|r|>0.6，P < 0.001）。D、PF和T2*值与部分生化指标（Scr和BUN）中度或低度相关（|r|<0.5，P < 0.05）。IVIM和BOLD可作为监测肾CIRI后不同程度肾功能损害及恢复情况的无创性影像学标志物。
