Schweitzer Andrew D, Liu Tian, Gupta Ajay, Zheng Karen, Seedial Stephen, Shtilbans Alexander, Shahbazi Mona, Lange Dale, Wang Yi, Tsiouris A John
1 Department of Radiology, New York-Presbyterian Hospital, Weill-Cornell Medical Center, 525 E 68th St, Starr 630-C, New York, NY 10065.
AJR Am J Roentgenol. 2015 May;204(5):1086-92. doi: 10.2214/AJR.14.13459.
The diagnosis of amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS) is often difficult because of a lack of disease biomarkers. The purpose of this study was to investigate quantitative susceptibility mapping (QSM) of the motor cortex as a potential quantitative biomarker for the diagnosis of ALS and PLS.
From a retrospective database, QSM images of 16 patients with upper motor neuron disease (nine men [56%], seven women; mean age, 56.3 years; 12 with ALS, four with PLS) and 23 control patients (13 men [56%], 10 women; mean age, 56.6 years) were reviewed. Two neuroradiologists, blinded to diagnosis, qualitatively assessed QSM, T2- and T2*-weighted, and T2-weighted FLAIR images. Relative motor cortex susceptibility was calculated by subtraction of adjacent white matter and CSF signal intensity from mean motor cortex susceptibility on the axial image most representative of the right- or left-hand lobule, and ROC analysis was performed. The Fisher exact and Student t tests were used to evaluate for statistical differences between the groups.
Qualitatively, QSM had greater diagnostic accuracy than T2-weighted, T2*-weighted, or T2-weighted FLAIR imaging for the diagnosis of ALS and PLS. Quantitatively, relative motor cortex susceptibility was found to be significantly greater in patients with motor neuron disease than in control patients (46.0 and 35.0 ppb; p < 0.001). ROC analysis showed an AUC of 0.88 (p < 0.0001) and an optimal cutoff value of 40.5 ppb for differentiating control patients from patients with ALS or PLS (sensitivity, 87.5%; specificity, 87.0%).
QSM is a sensitive and specific quantitative biomarker of iron deposition in the motor cortex in ALS and PLS.
由于缺乏疾病生物标志物，肌萎缩侧索硬化症（ALS）和原发性侧索硬化症（PLS）的诊断往往很困难。本研究的目的是调查运动皮层的定量磁化率图谱（QSM）作为诊断ALS和PLS的潜在定量生物标志物。
从一个回顾性数据库中，回顾了16例上运动神经元疾病患者（9名男性[56%]，7名女性；平均年龄56.3岁；12例ALS，4例PLS）和23名对照患者（13名男性[56%]，10名女性；平均年龄56.6岁）的QSM图像。两名对诊断不知情的神经放射科医生对QSM、T2加权、T2*加权和T2加权液体衰减反转恢复（FLAIR）图像进行了定性评估。通过从最能代表右手或左手小叶的轴位图像上的平均运动皮层磁化率中减去相邻白质和脑脊液信号强度来计算相对运动皮层磁化率，并进行受试者工作特征（ROC）分析。采用Fisher精确检验和Student t检验评估组间的统计学差异。
定性地说，对于ALS和PLS的诊断，QSM的诊断准确性高于T2加权、T2*加权或T2加权FLAIR成像。定量地说，发现运动神经元疾病患者的相对运动皮层磁化率显著高于对照患者（46.0和35.0 ppb；p<0.001）。ROC分析显示，将对照患者与ALS或PLS患者区分开来的曲线下面积（AUC）为0.88（p<0.0001），最佳截断值为40.5 ppb（敏感性，87.5%；特异性，87.0%）。
QSM是ALS和PLS运动皮层铁沉积的一种敏感且特异的定量生物标志物。
