Bermel Robert A, Sharma Jitendra, Tjoa Christopher W, Puli Srinivas R, Bakshi Rohit
University at Buffalo, State University of New York, USA.
J Neurol Sci. 2003 Apr 15;208(1-2):57-65. doi: 10.1016/s0022-510x(02)00425-2.
Brain atrophy is a proposed MRI marker of irreversible pathologic damage in multiple sclerosis (MS). The brain parenchymal fraction (BPF) is the ratio of brain parenchymal volume to the total volume within the surface contour. We developed a semiautomated measure of BPF using commercially available edge-finding and thresholding software (30-min analysis time per patient). We measured BPF in 78 patients with MS and 17 healthy controls. BPF was lower in a cohort of patients with MS (n=50) (0.843+/-0.042, range 0.743-0.906) age-matched to controls (0.877+/-0.020, range 0.835-0.901) (p<0.001). BPF correlated inversely with third ventricular width (r=-0.785, p<0.001), and total T1 hypointense lesion volume (r=-0.347, p=0.011), but not with total T2 hyperintense lesion volume (r=-0.213, p=0.13). BPF correlated negatively with expanded disability status scale (EDSS) score (r=-0.391, p=0.0006) and disease duration (r=-0.281, p=0.01). Stepwise regression compared the relative abilities of MRI variables to predict clinical data. By regression of age, BPF, third ventricular width, T2 lesions, and T1 lesions, BPF was the best predictor of disability score (R(2)=0.204, p<0.001). Third ventricular width was the best predictor of disease duration (R(2)=0.316, p<0.001). None of the MRI variables differed between relapsing-remitting (RR) (n=60) and secondary progressive (SP) (n=18) disease course (p>0.05). The intrarater, interrater, and scan-rescan BPF variability (COV) was 0.31%, 0.34%, and 0.41% and the accuracy against a phantom was 99.1%. We conclude that whole-brain atrophy in MS can be reliably and readily quantified by a semiautomated approach. Longitudinal studies are warranted to determine if this method provides a sensitive biologic marker of the MS disease process.
脑萎缩是多发性硬化症（MS）中不可逆病理损伤的一种潜在MRI标志物。脑实质分数（BPF）是脑实质体积与表面轮廓内总体积的比值。我们使用市售的边缘检测和阈值化软件开发了一种半自动的BPF测量方法（每位患者分析时间为30分钟）。我们测量了78例MS患者和17名健康对照者的BPF。与年龄匹配的对照组（0.877±0.020，范围0.835 - 0.901）相比，一组MS患者（n = 50）的BPF较低（0.843±0.042，范围0.743 - 0.906）（p<0.001）。BPF与第三脑室宽度呈负相关（r = -0.785，p<0.001），与总T1低信号病变体积呈负相关（r = -0.347，p = 0.011），但与总T2高信号病变体积无关（r = -0.213，p = 0.13）。BPF与扩展残疾状态量表（EDSS）评分呈负相关（r = -0.391，p = 0.0006），与病程呈负相关（r = -0.281，p = 0.01）。逐步回归比较了MRI变量预测临床数据的相对能力。通过对年龄、BPF、第三脑室宽度、T2病变和T1病变进行回归分析，BPF是残疾评分的最佳预测指标（R(2)=0.204，p<0.001）。第三脑室宽度是病程的最佳预测指标（R(2)=0.316，p<0.001）。复发缓解型（RR）（n = 60）和继发进展型（SP）（n = 18）病程的患者之间，MRI变量均无差异（p>0.05）。评分者内、评分者间以及扫描 - 重复扫描的BPF变异性（COV）分别为0.31%、0.34%和0.41%，对模型的准确性为99.1%。我们得出结论，MS中的全脑萎缩可以通过半自动方法可靠且容易地进行量化。有必要进行纵向研究以确定该方法是否能提供MS疾病进程的敏感生物学标志物。
