动脉自旋标记与多期增强技术评估不同年龄正常人肾血流

Arterial spin labeling and multi-phase enhancement technique in evaluation of renal blood flow in different age healthy subjects

目的采用MR动脉自旋标记(ASL)技术与MR多期增强评估不同年龄肾功能正常人群肾脏皮质血流的变化,并分析肾血流灌注与肾脏功能改变的关系。探讨ASL技术与多期增强技术评估肾血流灌注的差异。方法收集本院行MR检查的肾脏无明显病变、肾功能正常的21~80岁受检者178名,按年龄段分为3组(21~40岁组,41~60岁组,61~80岁组),每组各随机抽样20名进行分析。采用ASL技术获得肾血流量(RBF);采用多期增强扫描获得肾皮质早期增强率(ER);采用CKD-EPI公式估算肾小球滤过率(eGFR)。比较不同年龄组间RBF、ER和eGFR值,并分析其与年龄的相关性。结果 3组间RBF、eGFR比较差异均有统计学意义(P均<0.05),且21~40岁组与61~80岁组差异有统计学意义(P<0.05),余组间两两比较差异无统计学意义(P均>0.05);两两组间比较eGFR值差异均有统计学意义(P均<0.05)。3组间ER差异无统计学意义(P=0.05)。双肾RBF、ER、eGFR均与年龄呈负相关(r=-0.37、-0.38、-0.87,P均<0.01);RBF、ER与eGFR间均无相关性(r=0.208、0.223,P=0.111、0.087);RBF与ER无相关性(r=0.015,P=0.911)。结论正常肾功能人群随年龄增长,肾功能、肾血流量逐渐减低。ASL技术较多期增强技术对年龄增长导致的肾皮质血流的改变更加敏感。

Objective To assess the changes of renal cortical blood flow（RBF）in subjects with normal renal function of different age,and to analyze the relationship between renal perfusion and renal function changes by arterial spin labeling technique（ASL）and multi-phase enhanced MRI.Methods Totally 178 subjects who were confirmed without renal diseases and had normal renal function underwent MRI.The subjects were divided into 3groups according to age（21—40years old group,41—60years old group and 61—80years old group）,and 20 cases were randomly extracted from each group.RBF and enhancement ratio（ER）were acquired by ASL and multi-phase enhanced MR.Estimated glomerular filtration rate（eGFR）was calculated using the CKD-EPI formula.RBF,ER and eGFR values were compared among different groups,and their correlation with age were analyzed meanwhile.Results There were significant differences of RBF and eGFR among 3groups（P〈0.05）.The difference of RBF between 21—40years old and 61—80years old group was significantly（P〈0.05）,but there were no significant differences in pairwise comparison between other groups.There were significant differences of eGFR among 3groups and inter group comparison（all P〈0.05）.There was no significant difference of ER among 3groups（P=0.05）.The RBF,ER and eGFR showed negative correlations with age（r=-0.37,-0.38,-0.87,all P〈0.01）.There were no significant correlations between RBF,ER and eGFR（r=0.208,0.223,P=0.111,0.087）.There was no correlation between RBF and ER（r=0.015,P=0.911）.Conclusion With age increasing,renal function and perfusion decrease gradually in normal range.ASL is more sensitive than multi-phase enhancement technique for detecting the changes of renal cortical perfusion caused by aging.