Schultz Vivian, Hedderich Dennis M, Schmitz-Koep Benita, Schinz David, Zimmer Claus, Yakushev Igor, Apostolova Ivayla, Özden Cansu, Opfer Roland, Buchert Ralph
Department of Neuroradiology, Klinikum Rechts Der Isar, Technical University of Munich, School of Medicine and Health, Ismaninger Str. 22, 81675, Munich, Germany.
Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen (FAU), Nürnberg, Germany.
Neuroradiology. 2024 Apr;66(4):507-519. doi: 10.1007/s00234-024-03304-3. Epub 2024 Feb 21.
Single-subject voxel-based morphometry (VBM) compares an individual T1-weighted MRI to a sample of normal MRI in a normative database (NDB) to detect regional atrophy. Outliers in the NDB might result in reduced sensitivity of VBM. The primary aim of the current study was to propose a method for outlier removal ("NDB cleaning") and to test its impact on the performance of VBM for detection of Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD).
T1-weighted MRI of 81 patients with biomarker-confirmed AD (n = 51) or FTLD (n = 30) and 37 healthy subjects with simultaneous FDG-PET/MRI were included as test dataset. Two different NDBs were used: a scanner-specific NDB (37 healthy controls from the test dataset) and a non-scanner-specific NDB comprising 164 normal T1-weighted MRI from 164 different MRI scanners. Three different quality metrics based on leave-one-out testing of the scans in the NDB were implemented. A scan was removed if it was an outlier with respect to one or more quality metrics. VBM maps generated with and without NDB cleaning were assessed visually for the presence of AD or FTLD.
Specificity of visual interpretation of the VBM maps for detection of AD or FTLD was 100% in all settings. Sensitivity was increased by NDB cleaning with both NDBs. The effect was statistically significant for the multiple-scanner NDB (from 0.47 [95%-CI 0.36-0.58] to 0.61 [0.49-0.71]).
NDB cleaning has the potential to improve the sensitivity of VBM for the detection of AD or FTLD without increasing the risk of false positive findings.
基于体素的单受试者形态测量法（VBM）将个体的T1加权磁共振成像（MRI）与标准数据库（NDB）中的正常MRI样本进行比较，以检测局部萎缩。NDB中的异常值可能会导致VBM的敏感性降低。本研究的主要目的是提出一种去除异常值的方法（“NDB清理”），并测试其对VBM检测阿尔茨海默病（AD）和额颞叶痴呆（FTLD）性能的影响。
纳入81例生物标志物确诊的AD患者（n = 51）或FTLD患者（n = 30）以及37例同时进行氟代脱氧葡萄糖正电子发射断层扫描/磁共振成像（FDG-PET/MRI）的健康受试者的T1加权MRI作为测试数据集。使用了两种不同的NDB：特定扫描仪的NDB（来自测试数据集的37例健康对照）和非特定扫描仪的NDB，其包含来自164台不同MRI扫描仪的164份正常T1加权MRI。基于对NDB中扫描的留一法测试实施了三种不同的质量指标。如果某扫描相对于一个或多个质量指标为异常值，则将其移除。对有和没有NDB清理情况下生成的VBM图谱进行视觉评估，以确定是否存在AD或FTLD。
在所有设置中，VBM图谱视觉解读检测AD或FTLD的特异性均为100%。两种NDB进行NDB清理后敏感性均有所提高。对于多扫描仪NDB，该效果具有统计学意义（从0.47 [95%置信区间0.36 - 0.58]提高到0.61 [0.49 - 0.71]）。
NDB清理有可能提高VBM检测AD或FTLD的敏感性，而不会增加假阳性结果的风险。
