Abstract:
Purpose: 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. Methods: 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). Results: The D, D*, PF and T2* values in the CIRI groups were lower than those in the sham-operated group at all timepoints (all p < 0.05). The prolonged cold ischemia times resulted in gradually lower D, D*, PF and T2* values (all p < 0.05). The D and T2* values of cortex and OSOM in Group T0 and T2 returned to the baseline level (all p > 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 p < 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, p < 0.001). D*, PF and T2* values were moderately to poorly correlated with some biochemistry indicators (Scr and BUN) (|r|<0.5, p < 0.05). Conclusion: IVIM and BOLD can serve as noninvasive radiologic markers for monitoring different degrees of renal impairment and recovery after renal CIRI.
摘要:
目的:冷缺血再灌注损伤(CIRI)是肾移植术后最严重的并发症之一。本研究探讨了体素内不相干运动(IVIM)成像和血氧水平依赖性(BOLD)评估大鼠模型不同程度的肾脏冷缺血再灌注损伤的可行性。方法:75只大鼠随机分为3组(每组25只):T0:假手术组,T2/T4:不同冷缺血时间的CIRI组(2、4h,分别)。CIRI组大鼠采用左肾冷缺血加右肾切除术建立模型。所有大鼠在手术前接受基线MRI。每组随机选择5只大鼠于1h进行MRI检查,CIRI后第1天、第2天和第5天。在肾皮质(CO)中研究了IVIM和BOLD参数,外髓质的外部条纹(OSOM),和外髓质的内部条纹(ISOM),然后进行组织学分析以检查Paller评分,肾小管周围毛细血管(PTC)密度,细胞凋亡率和生化指标获得血清肌酐(Scr)含量,血尿素氮(BUN),超氧化物歧化酶(SOD)和丙二醛(MDA)。结果:D,D*,在所有时间点,CIRI组的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逐渐降低,D*,PF和T2*值(所有p<0.05)。除T4组外,T0和T2组的皮质和OSOM的D和T2*值恢复至基线水平(均p>0.05)。皮质的D*和PF值,除T0组外,T2和T4组的OSOM和ISOM仍低于正常水平(均p<0.05)。D,D*,PF和T2*值与组织病理学密切相关(帕勒评分,PTC密度和凋亡率)和生化指标(SOD和MDA)(|r|>0.6,p<0.001)。D*,PF和T2*值与某些生化指标(Scr和BUN)的相关性中等到较差(|r|<0.5,p<0.05)。结论:IVIM和BOLD可作为无创的影像学指标,用于监测肾性CIRI后不同程度的肾功能损害和恢复。