Rovaris M, Gawne-Cain M L, Sormani M P, Miller D H, Filippi M
Department of Neurology, IRCCS Ospedale San Raffaele, University of Milan, Italy.
J Neurol. 1998 May;245(5):273-5. doi: 10.1007/s004150050217.
The aim of this study was to assess the variability of lesion load measurements for repeated brain magnetic resonance imaging (MRI) scans judged to have either poor or good repositioning quality on the basis of subjective criteria used for clinical trials in multiple sclerosis (MS). Scan-rescan variability was also compared with the intra-observer variability assessed from three repeated volume measurements of the same scan. Nine patients with MS were studied; each of them underwent the scan-rescan procedure on the same day. Five scans were considered to have poor and four scans to have good repositioning. Between these two groups there were no differences in either the mean lesion loads or the measurement variance. For the whole group of patients, the intra-observer variability of repeated measurements gave a significantly lower coefficient of variation (COV = 4.9%) than the variability owing to repositioning (COV = 8.9%, P < 0.01, F test). Our results confirm that the effect of repositioning on brain MRI lesion load assessment is stronger than that owing to the intra-observer variability for repeated measurements and indicate that the simple visual judgment about the scan repositioning quality seems unable to predict the scan-rescan reproducibility.
本研究的目的是评估基于用于多发性硬化症（MS）临床试验的主观标准，判断为重新定位质量差或好的重复脑磁共振成像（MRI）扫描的病灶负荷测量的变异性。还将扫描 - 再扫描变异性与从同一扫描的三次重复体积测量评估的观察者内变异性进行了比较。对9例MS患者进行了研究；他们每个人在同一天接受了扫描 - 再扫描程序。五例扫描被认为重新定位质量差，四例扫描被认为重新定位质量好。在这两组之间，平均病灶负荷或测量方差均无差异。对于整个患者组，重复测量的观察者内变异性给出的变异系数（COV = 4.9%）显著低于由于重新定位导致的变异性（COV = 8.9%，P < 0.01，F检验）。我们的结果证实，重新定位对脑MRI病灶负荷评估的影响比对重复测量的观察者内变异性的影响更强，并表明关于扫描重新定位质量的简单视觉判断似乎无法预测扫描 - 再扫描的可重复性。
