Razek Ahmed Abdel, Elmorsy Ahmed, Elshafey Mohsen, Elhadedy Tamer, Hamza Osama
Department of Diagnostic Radiology, Mansoura Faculty of Medicine, Mansoura, Egypt.
J Magn Reson Imaging. 2009 Sep;30(3):535-40. doi: 10.1002/jmri.21871.
To assess the role of diffusion-weighted single-shot echo-planar magnetic resonance imaging (MRI) in patients with mediastinal tumors.
Prospective study was conducted on 45 consecutive patients (29 male, 16 female, age 22-66 years, mean 41 years) with mediastinal tumor. They underwent diffusion-weighted single-shot echo-planar MRI of the mediastinum with a b-factor of 0, 300, and 600 sec/mm(2). The apparent diffusion coefficient (ADC) value of the mediastinal tumor was correlated with the histopathological findings.
The mean ADC value of malignant mediastinal tumors was 1.09 +/- 0.25 x 10(-3) mm(2)/sec, and of benign tumors was 2.38 +/- 0.56 x 10(-3) mm(2)/sec. There was a significant difference in the mean ADC value between malignant and benign tumors (P = 0.001) and within different grades of malignancy (0.001). When an ADC value of 1.56 x 10(-3) mm(2)/sec was used as a threshold value for differentiating malignant from benign tumor, the best results were obtained with an accuracy of 95%, sensitivity of 96%, specificity of 94%, positive predictive value of 94%, negative predictive value of 96%, and area under the curve of 0.938.
The ADC value is a noninvasive parameter that can be used for differentiation of malignant from benign mediastinal tumors and grading of mediastinal malignancy.
评估扩散加权单次激发回波平面磁共振成像（MRI）在纵隔肿瘤患者中的作用。
对45例连续的纵隔肿瘤患者（男29例，女16例，年龄22 - 66岁，平均41岁）进行前瞻性研究。他们接受了b值为0、300和600 sec/mm²的纵隔扩散加权单次激发回波平面MRI检查。纵隔肿瘤的表观扩散系数（ADC）值与组织病理学结果相关。
恶性纵隔肿瘤的平均ADC值为1.09±0.25×10⁻³mm²/sec，良性肿瘤为2.38±0.56×10⁻³mm²/sec。恶性和良性肿瘤之间的平均ADC值存在显著差异（P = 0.001），在不同恶性程度之间也存在显著差异（P = 0.001）。当以1.56×10⁻³mm²/sec的ADC值作为区分恶性与良性肿瘤的阈值时，获得了最佳结果，准确率为95%，敏感性为96%，特异性为94%，阳性预测值为94%，阴性预测值为96%，曲线下面积为0.938。
ADC值是一种可用于区分纵隔恶性肿瘤与良性肿瘤以及纵隔恶性程度分级的无创参数。
