3T磁共振双反转恢复成像海马测量的可靠性分析

[目的]探讨正常人海马3T MR双反转恢复成像（double inversion recovery,DIR）测量的稳定性及可重复性.[方法]采用3T MR对20例健康志愿者行斜冠状位海马DIR扫描,由两位放射学医师测量海马头部、体部、尾部及尾状核的信号强度,分别计算并比较观察者之内、观察者之间的海马相对信号强度（relative signal intensity,RSI）有无差异.[结果]正常人两侧间海马RSI无显著性差异（P＜0.05）,正常海马平均RSI为（1.204±0.041）.同一观察者两次测量的海马RSI无显著性差异（P＜0.05）,组内相关系数为81.9％；两名观察者测量的海马RSI无显著性差异（P＜0.05）,组内相关系数为84.6％.Bland-Ahman分析显示海马RSI测量在观察者之内、观察者之间具有较好的稳定性及可重复性.[结论]海马DIR的RSI测量具有较高的可靠性,可以被用于定量评价海马病变的影像学改变.

Double inversion recovery of hippocampus at 3T MR: reliability of measurements in healthy volunteers

[Objective] To explore the repeatability and stability of measurements of double inversion recovery （DIR） imaging in hippocampus at 3T MR. [ Methods ] Twenty healthy control subjects were included and two scans were performed using DIR sequence vertical to the hippocampal axis at 3T MR. Regions of interest were placed on the head, body and tail levels of the hippocampus, and caudate nucleus and signal intensity was measured. Intra- and inter-observer variability of hippocampal relative signal intensity （RSI） were calculated and comparinf using a two-sided, paired-samples Student＇s t-test. [Results] There was no significant difference in hippocampal RSI between left and right sides, and mean RSI of bilateral hippocampi was （1.204 ± 0.04）. No significant difference in hippocampal RS! was found between two meansurements of one observer, and intraclass correlation coefficient （ICC） was 81.9%. Moreover, there was also no significant difference in measurement of hippocampal RSI between two observers, and the ICC was 84.6%. Bland-Ahman analysis demonstrated a good level of test-retest reliability and inter-observer reliability in measurement of hippocampal RSI. [Conclusion] This study shows the reliability cff measurement in hippocampal RSI in 3T MR which can be used for quantitative assessment of imaging changes in hippocampal lesion.