Department of Diagnostic Radiology, Kitasato University School of Medicine, Minamiku, Kanagawa, Japan.
Radiographics. 2011 Jul-Aug;31(4):1059-84. doi: 10.1148/rg.314105160.
Diffusion-weighted imaging provides a novel contrast mechanism in magnetic resonance (MR) imaging and has a high sensitivity in the detection of changes in the local biologic environment. A significant advantage of diffusion-weighted MR imaging over conventional contrast material-enhanced MR imaging is its high sensitivity to change in the microscopic cellular environment without the need for intravenous contrast material injection. Approaches to the assessment of diffusion-weighted breast imaging findings include assessment of these data alone and interpretation of the data in conjunction with T2-weighted imaging findings. In addition, the analysis of apparent diffusion coefficient (ADC) value can be undertaken either in isolation or in combination with diffusion-weighted and T2-weighted imaging. Most previous studies have evaluated ADC value alone; however, overlap in the ADC values of malignant and benign disease has been observed. This overlap may be partly due to selection of b value, which can influence the concomitant effect of perfusion and emphasize the contribution of multicomponent model influences. The simultaneous assessment of diffusion-weighted and T2-weighted imaging data and ADC value has the potential to improve specificity. In addition, the use of diffusion-weighted imaging in a standard breast MR imaging protocol may heighten sensitivity and thereby improve diagnostic accuracy. Standardization of diffusion-weighted imaging parameters is needed to allow comparison of multicenter studies and assessment of the clinical utility of diffusion-weighted imaging and ADC values in breast evaluation.
扩散加权成像在磁共振成像（MR）中提供了一种新的对比机制，对局部生物环境变化的检测具有很高的敏感性。与传统的对比增强磁共振成像相比，扩散加权磁共振成像有一个显著的优势，即其对微观细胞环境变化的敏感性很高，而无需静脉注射对比剂。评估扩散加权乳腺成像结果的方法包括单独评估这些数据，以及结合 T2 加权成像结果来解释这些数据。此外，可以单独或与扩散加权和 T2 加权成像结合来分析表观扩散系数（ADC）值。大多数先前的研究都单独评估了 ADC 值，但是已经观察到恶性和良性疾病的 ADC 值存在重叠。这种重叠可能部分归因于 b 值的选择，这会影响灌注的伴随效应并强调多成分模型影响的贡献。同时评估扩散加权和 T2 加权成像数据以及 ADC 值有可能提高特异性。此外，在标准乳腺 MR 成像方案中使用扩散加权成像可以提高敏感性，从而提高诊断准确性。需要对扩散加权成像参数进行标准化，以便能够比较多中心研究，并评估扩散加权成像和 ADC 值在乳腺评估中的临床应用价值。
