Department of Diagnostic Radiology, Mansoura Faculty of Medicine, Mansoura, Egypt.
Radiol Med. 2011 Feb;116(1):125-32. doi: 10.1007/s11547-010-0588-y. Epub 2010 Sep 17.
This study was done to assess the role of diffusion-weighted magnetic resonance (MR) imaging in assessing malignant versus benign skull lesions.
A retrospective analysis was undertaken of 45 patients (26 male, 19 female; age range 14-68 years, mean age 39 years) with skull-base lesions. Diffusion-weighted MR images were acquired with a b-factor of 500 and 1,000 s/mm(2) using single-shot echoplanar imaging. Apparent diffusion coefficient (ADC) maps were reconstructed, and the ADC value of the lesion was calculated.
The mean ADC value of malignant tumours was (1.002 ± 0.21) × 10(-3) mm(2)/s and that of benign tumours was (1.63 ± 0.29) × 10(-3) mm(2)/s. There was a statistically significant difference (p=0.001) in the ADC value of malignant skull-base tumours versus benign lesions. Selection of (1.3) × 10(-3)mm(2)/s as a threshold value of ADC for differentiating benign from malignant tumours yielded the best result, with an accuracy of 94%, sensitivity of 94%, specificity of 93%, positive predictive value of 93%, negative predictive value of 94% and area under the curve of 0.932.
We conclude that diffusion-weighted MR imaging is a promising, noninvasive approach that can be used to characterise skull-base lesions in that it can help differentiate malignant tumours from benign lesions and evaluate the pathological grading of malignant tumours.
本研究旨在评估磁共振弥散加权成像（DW-MRI）在评估颅骨良恶性病变中的作用。
回顾性分析 45 例（男 26 例，女 19 例；年龄 14-68 岁，平均 39 岁）颅骨底病变患者的资料。采用单次激发平面回波成像序列，b 值分别为 500 和 1000 s/mm²，行弥散加权成像。重建表观弥散系数（ADC）图，计算病变的 ADC 值。
恶性肿瘤的平均 ADC 值为（1.002±0.21）×10⁻³mm²/s，良性肿瘤的平均 ADC 值为（1.63±0.29）×10⁻³mm²/s。恶性颅骨底肿瘤与良性病变的 ADC 值差异有统计学意义（p=0.001）。选择（1.3）×10⁻³mm²/s 作为 ADC 值鉴别良恶性肿瘤的阈值，诊断的准确性为 94%，敏感度为 94%，特异度为 93%，阳性预测值为 93%，阴性预测值为 94%，曲线下面积为 0.932。
我们认为，弥散加权磁共振成像作为一种有前途的非侵入性方法，可以用于评估颅骨底病变，有助于鉴别良恶性肿瘤，并评估恶性肿瘤的病理分级。
