肾缺血再灌注损伤的MRI磁敏感成像研究

缺血再灌注损伤（IRI）是肾移植最常见的并发症，导致肾细胞功能、代谢异常，并且加重肾脏结构的破坏。血清肌酐水平是目前临床监测IRI的主要手段，但是敏感性低，无法早期反映组织病理生理的变化。本研究创新性地利用磁敏感成像(SWI)对肾脏IRI进行针对性研究。肾IRI24小时内肾间质内存在大量散在的红细胞，甚至是小出血灶；24-72小时肾小管上皮细胞同时出现凋亡和再生。SWI对出血的高敏感性使其能够较其他技术更早的观察到上述的病理变化。除了形态学上的变化，本研究利用SWI相位图定量分析肾静脉的血氧饱和度，比较IRI发生前后、治疗前后肾静脉血氧饱和度变化，并与血氧水平依赖成像进行横向比较，探讨SWI在功能学方面的价值。本研究利用SWI从功能学和形态学两个角度研究肾IRI，研究结果对于IRI的早期发现和治疗有重要价值，有助于改善患者预后，提高生存质量。

Ischemia-reperfusion injury (IRI) is the most common complication secondary to renal transplantation. It can cause the abnormality of cellular functions and metablism and make renal structions destroyed worse. The levels of serum creatinine is a mainly clinical marker for monitoring IRI with low sensititivity and cannot reflect early pathophysiologic alterations of renal tissues. In this study, susceptibility weighted imaging (SWI) is creactively used to evaluate the renal IRI. In 24 hours after the onset of renal IRI, a lot of red cells, even some small hemorrhagic lesions, are seen in renal mesenchyme. Renal tubular epithelial cells appear apoptosis and regeneration simultaneously in 24-72 hours after the onset of renal IRI. SWI can detect these pathological conditions with it more sensitivity to hemorrhage than other modalities. Except for the morphological changes, oxygen saturations of renal veins can also be quantitatively measured on phase imagings in this study. Based on this technique, the variations of oxygen saturations of renal veins before and after the onset of IRI or before and after the treatment for IRI are compared. The results of SWI also are compared with that of blood oxygenation-level dependent imaging in order to evaluate the value of SWI in function. In this study, SWI is used to assess renal IRI on morphology and function. Our results are important to early detect and cure IRI and can improve the prognosis and survival.