正常人动脉自旋标记肾血流灌注最佳标记后延迟时间分析

Optimal Post Label Delay of ASL Renal Blood Perfusion in Normal People

目的探讨动脉自旋标记(ASL)在正常人肾血流灌注成像中最佳标记后延迟时间(PLD)。方法选取30名健康成人志愿者(男18名,女12名;年龄25~60岁,平均48岁),行常规T2WI和不同PLD的ASL检查。对三组(不同PLD)ASL原始图像、灌注伪彩图以4分制进行独立图像质量评分。两位观察者图像质量评分的一致性采用Kappa检验。测量各组图像肾皮、髓质的肾血流量(RBF)。采用单因素方差分析比较不同组间图像平均评分和肾皮、髓质RBF值的差异,两两比较采用Bonferroni法。结果两位观察者对三组PLD(1525 ms,2025 ms,2525 ms)图像质量评分一致性较好(k原始图像=0.658、0.798、0.683,k灌注伪彩图=0.881、0.603、0.665)。PLD为2025 ms时,图像质量平均评分(原始图像:3.57±0.45 vs 2.90±0.56、2.11±0.57;灌注伪彩图:3.40±0.59 vs 2.75±0.54、1.78±0.64)和肾皮质RBF值[(242.12±41.79)ml·100g-1·min-1 vs(213.66±37.78)ml·100g-1·min-1、(187.34±42.34)ml·100g-1·min-1]均高于PLD值为1525 ms和2525 ms图像,三组间两两比较差异均有统计学意义(P<0.05)。各组肾髓质RBF无明显差异[(88.12±23.56)ml·100g-1·min-1、(88.95±18.27)ml·100g-1·min-1、(92.83±18.80)ml·100g-1·min-1,P>0.05]。结论当PLD=2025 ms时,对正常人肾脏血流灌注的评估效果最好。

Objective To explore the most optimal post labeling delay(PLD)on ASL renal blood flow in normal adult.Methods 30 healthy adults(18 men and 12 women;age range was 25~60 years,mean of 48 yrs)were included in this prospective study.Conventional T2-weighted imaging(T2WI)and three ASL with different PLD time(1525 ms,2025 ms,2525 ms)were acquired.Two radiologists evaluated image quality and scored by 4 points for ASL.Kappa test was applied to verify image quality consistency of the two observers.Renal cortex and medulla renal blood flow(RBF)was measured.The average score of image quality,cortex and medulla RBF between different groups was compared using one-way analysis of variance(ANOVA)and Bonferroni.Results There was strong consistency between two observers with different PLD time(1525 ms,2025 ms,2525 ms)(koriginal images=0.798、0.658、0.683,kpseudocolor images=0.603、0.881、0.665,>0.6);when PLD time was 2025 ms,the score of image quality(raw image:3.57±0.45 vs 2.90±0.56、2.11±0.57;functionl image:3.40±0.59 vs 2.75±0.54、1.78±0.64)and cortex RBF[(242.12±41.79)ml·100 g-1·min-1 vs(213.66±37.78)ml·100 g-1·min-1、(187.34±42.34)ml·100 g-1·min-1]were higher than those in images with PLD of 1525 ms and 2525 ms.There was significant difference among the three groups respectively(P<0.05).There was no significant difference in the medulla RBF between the three groups[(88.12±23.56)ml·100 g-1·min-1、(88.95±18.27)ml·100 g-1·min-1、(92.83±18.80)ml·100 g-1·min-1,P>0.05].Conclusion The best PLD time in evaluation of renal ASL perfusion image of normal adult is 2025 ms.