时间-空间标记反转脉冲技术在肾脏皮髓质分离中的应用及时间参数优化

Application of time-spatial labeling inversion pulse in renal corticomedullary differentiation and time parameter optimization

目的探讨磁共振时间—空间双重标记反转脉冲(T-SLIP)技术在肾脏皮髓质分离中的应用及显示肾脏皮髓质分离最佳的黑血翻转时间(BBTI)。方法选择健康志愿者60名,采用结合T-SLIP脉冲的稳态自由进动序列(SSFP)行上腹部扫描。采用6个BBTI值(800、1 000、1 200、1 400、1 600、1 800ms)进行冠状位T-SLIP SSFP序列扫描。采用4分法分析图像质量,并通过图像训练算法自动分割肾脏皮髓质区域,分别计算皮髓质的信号强度(SI),获得不同BBTI值时肾脏皮髓质的相对信号强度比(SIR),获得最佳BBTI值。结果 BBTI值为1 200ms时,图像质量的评分最高。不同BBTI值时,SIR差异有统计学意义(P=0.013),当BBTI为1 200ms时,SIR值最大,肾皮髓质间SI对比最明显。结论 T-SLIP技术可在不使用对比剂的情况下清晰显示肾脏皮髓质,当BBTI值为1 200ms时皮髓质分离显示最好。

Objective To investigate the application value of time-spatial labeling inversion pulse（T-SLIP）in renal corticomedullary differentiaton and the best black blood inversion time（BBTI）value.Methods Totally 60 volunteers were included,who underwent abdominal MR scan with noncontrast-enhanced SSFP sequence combined with T-SLIP.All subjects were scanned with different BBTI（800,1000,1200,1400,1600,1800ms）using coronary T-SLIP SSFP sequence.The images quality was evaluated using a four-point scale method.The region of renal cortex and medulla was devised automatically based on the image training algorithm.The signal intensity ratio with the different BBTI was calculated through measuring the signal intensity of the renal cortex and medulla.And the best BBTI values were analyzed.Results When BBTI was 1200 ms,the image score was the highest.The signal intensity ratio（SIR）had statistical difference among different BBTI groups（all P〈0.05）,when BBTI was 1200 ms,the SIR was the highest,and the contrast between the renal cortex and medulla was obvious.Conclusion T-SLIP technology can improve the visibility of renal corticomedullary without contrast agents.The optimal BBTI for the best corticomedullary differentiation is 1200 ms.