肾动脉狭窄患者血氧水平依赖磁共振成像研究

摘要

Objective:The purpose of this article is comparing R2 * value in renal artery stenosis patients with R2 * value in control groups and the degree of renal artery stenosis of its own by blood oxygen leveldependent (BOLD) magnetic resonance imaging (MRI).Methods:28 patients with renal artery stenosis and 16 healthy volunteers received renal BOLD MRI examination on Siemens 3.0T scanner.Post-process and analysis were performed on Siemens workstation and Matlab.R2 * value (1/sec) of cortex and medulla were recorded and analyzed respectively.Results:Medulla R2 * value was higher than cortex R2 * value in control group.No significant difference in R2 * value was found in different parts (upper,middle,lower part) of kidneys.Both cortex and medulla R2 * value in renal artery stenosis patients (21.14 ± 4.90);(36.25 ± 8.04) were higher than corresponding R2 * value in control group with a significant gap (P ＜ 0.05),and a more sensitive change in medulla R2 * value was found.Among different subgroups in patient group,medulla R2 * value in severe stenosis group (44.20 ± 6.01) was higher than other subgroups (P ＜ 0.05),but cortex R2 * value in severe stenosis group(24.06 ±5.94) was found no significant difference from mild stenosis,moderate stenosis subgroups (20.20 ± 2.01);(19.14 ± 1.86) while it was higher than unobstructed subgroup (18.96 ± 3.62) (P ＜ 0.05).No correlation was found between R2 * value and glomerular filtration rate of the same kidney in cortex or medulla.Conclusion:BOLD MRI is an effective and noninvasive method to evaluate the oxygenation state of kidney.It can play an important role in estimation of stenosis degree of renal artery.BOLD MRI is a sensitive tool which can be used to detect ischemia and anoxia of medulla of kidney.%目的:运用血氧水平依赖磁共振成像(BOLD MRI)序列评估肾动脉狭窄患者肾脏氧合状态,分析患者肾脏R2*值与健康人R2*值及自身肾动脉狭窄程度之间的关系.方法:使用西门子3.0T磁共振机对28例肾动脉狭窄患者及16例健康志愿者的肾脏进行BOLD扫描,所得图像通过西门子工作站及MATLAB软件进行处理分析、手动勾画感兴趣区,得到R2*值,进行分析比较.结果:正常健康人肾髓质R2*值(29.61±2.26)高于皮质(18.23±1.77),肾脏上、中、下部R2*值差异无统计学意义.肾动脉狭窄患者肾皮质、髓质R2*值(21.14 ±4.90);(36.25 ±8.04)均较正常人有显著增高,其差异具有统计学意义(P＜0.05),且髓质变化更为敏感.在患者组各亚组中,肾动脉重度狭窄患者肾髓质R2 *值(44.20±6.01)较其他各亚组明显增高,差异具有统计学意义(P＜0.05),而肾动脉重度狭窄患者肾皮质R2*值(24.06±5.94)仅显著高于无明显狭窄组(18.96±3.62) (P ＜0.05),与轻、中度狭窄患者(20.20±2.01);(19.14±1.86)并差异无统计学意义.分别对患者组皮质和髓质R2*值与所对应一侧肾脏肾小球滤过率进行相关性分析,未发现有显著的相关性.结论:BOLD MRI序列是一种有效的无创性评估肾脏氧合状态的检查方法,在肾动脉狭窄程度的判断上具有一定的意义和作用,而且是检测肾髓质缺血缺氧的敏感手段.