用于诊断正常压力脑积水的相位对比磁共振成像脑脊液流量测量：速度与体积参数的观察者一致性

Phase-Contrast MRI CSF Flow Measurements for the Diagnosis of Normal-Pressure Hydrocephalus: Observer Agreement of Velocity Versus Volume Parameters.

作者信息

Tawfik Ahmed Mohamed, Elsorogy Lamiaa, Abdelghaffar Rabab, Naby Ayman Abdel, Elmenshawi Ibrahim

机构信息

1 Department of Diagnostic and Interventional Radiology, Mansoura University, 12 El-Gomhoreya St, Mansoura 35112, Egypt.

2 Department of Neurology, Mansoura University, Mansoura, Egypt.

出版信息

AJR Am J Roentgenol. 2017 Apr;208(4):838-843. doi: 10.2214/AJR.16.16995. Epub 2017 Jan 31.

DOI:10.2214/AJR.16.16995

PMID:28140607

Abstract

OBJECTIVE

Manual segmentation of the aqueduct for CSF flow analysis may induce measurement variability. The aim of our study was to assess observer agreement of manual segmentation and to compare the repeatability and accuracy of different flow parameters in differentiating normal-pressure hydrocephalus (NPH) from brain atrophy.

SUBJECTS AND METHODS

Thirty-two subjects were included and were divided into three groups: control, NPH, and brain atrophy. Subjects underwent phase-contrast MRI. Quantitative analysis of aqueductal CSF flow using manual ROI placement was performed by two independent readers. Reader 1 repeated measurements 3 months after the first session to assess interobserver and intraobserver agreement. Intraclass correlation coefficients (ICCs), within-subject SD, and repeatability were calculated. Peak systolic velocity (PSV), peak mean velocity, and aqueductal CSF stroke volume, which we refer to as "stroke volume," were recorded and compared between the three patient groups. The ROC curves of diagnostic accuracy for NPH were compared.

RESULTS

PSV was ROI-independent, so only one measurement was obtained. The NPH group had significantly higher PSV, peak mean velocity, and stroke volume values in all readings than both the control and brain atrophy groups. The accuracy of PSV for the diagnosis of NPH was 82.7%, and the accuracy of peak mean velocity was 92.5-93.3% for the three readings. Stroke volume had perfect accuracy of 100% for the three readings. The stroke volume had higher ICCs (0.97 and 0.98) than the peak mean velocity (0.88). The intraobserver repeatability and interobserver repeatability of peak mean velocity were 1.9 cm/s, and the intraobserver repeatability and interobserver repeatability of stroke volume were 27.4 and 19.6 µL/cycle, respectively.

CONCLUSION

Stroke volume had better agreement and repeatability and was more accurate than peak mean velocity for the diagnosis of NPH. PSV lacks variability but was the least accurate.

摘要

目的

通过手动分割导水管来分析脑脊液流动可能会导致测量的变异性。本研究的目的是评估手动分割的观察者间一致性，并比较不同血流参数在区分正常压力脑积水（NPH）和脑萎缩方面的可重复性和准确性。

受试者与方法

纳入32名受试者，分为三组：对照组、NPH组和脑萎缩组。受试者接受相位对比磁共振成像（MRI）检查。由两名独立的阅片者通过手动放置感兴趣区（ROI）对导水管脑脊液流动进行定量分析。阅片者1在第一次检查3个月后重复测量，以评估观察者间和观察者内的一致性。计算组内相关系数（ICC）、受试者内标准差和可重复性。记录并比较三组患者的收缩期峰值流速（PSV）、平均峰值流速和导水管脑脊液每搏量（我们称之为“每搏量”）。比较NPH诊断准确性的ROC曲线。

结果

PSV与ROI无关，因此仅获得一次测量值。在所有读数中，NPH组的PSV、平均峰值流速和每搏量值均显著高于对照组和脑萎缩组。PSV诊断NPH的准确率为82.7%，三次读数中平均峰值流速的准确率为92.5% - 93.3%。三次读数中每搏量的诊断准确率均为100%。每搏量的ICC（0.97和0.98）高于平均峰值流速（0.88）。平均峰值流速的观察者内可重复性和观察者间可重复性为1.9 cm/s，每搏量的观察者内可重复性和观察者间可重复性分别为27.4和19.6 μL/周期。