Department of Radiology, San Bonifacio Hospital, Verona, Italy.
J Magn Reson Imaging. 2012 Oct;36(4):858-64. doi: 10.1002/jmri.23706. Epub 2012 May 30.
To assess prospectively the accuracy of diffusion-weighted magnetic resonance imaging (DWI) in differentiating between metastatic and benign axillary lymph nodes in patients with breast cancer.
In all, 215 patients with histologically proven breast cancer, prior to axillary dissection, underwent breast and axillary 1.5 T MRI. In 102 patients in whom at least one axillary lymph node with a short axis of 6 mm or more was found the apparent diffusion coefficient (ADC) was measured in one lymph node per patient by means of an echo planar, parallel imaging DWI sequence. Forty-three lymph nodes were finally included which, on histological examination, either contained a metastasis larger than 5 mm or were metastasis-free; nodes with metastases smaller than 5 mm were excluded.
From histological examination, 19/43 lymph nodes had a metastasis at least 5 mm, while in 24/43 no malignant cells were found. The ADC values of the lymph nodes with metastases (mean: 0.878 × 10(-3) mm(2) /s; range: 0.30 -1.20) were significantly lower (P < 0.001) than those of the benign lymph nodes (mean: 1.494; range: 0.60 -2.50). Adopting a threshold value of 1.09 × 10(-3) mm(2) /s DWI resulted in 94.7% sensitivity, 91.7% specificity, and 93.0% accuracy in the identification of metastasis in this series of lymph nodes.
From these preliminary data DWI seems a promising method in the differential diagnosis between metastatic and benign axillary lymph nodes in patients with breast cancer.
前瞻性评估磁共振弥散加权成像（DWI）在鉴别乳腺癌患者腋窝转移性和良性淋巴结中的准确性。
共 215 例经组织学证实的乳腺癌患者在腋窝清扫术前行 1.5 T 乳腺和腋窝 MRI 检查。在至少有一个短轴 6 毫米或以上的腋窝淋巴结的 102 例患者中，通过平面回波、并行成像 DWI 序列在每位患者的一个淋巴结中测量表观弥散系数（ADC）。最终包括 43 个淋巴结，这些淋巴结在组织学检查中，要么包含一个大于 5 毫米的转移灶，要么没有转移灶；排除了小于 5 毫米的转移灶。
从组织学检查中，19/43 个淋巴结有至少 5 毫米的转移，而在 24/43 个淋巴结中未发现恶性细胞。转移淋巴结的 ADC 值（平均值：0.878×10(-3) mm(2) /s；范围：0.30-1.20）明显低于（P < 0.001）良性淋巴结的 ADC 值（平均值：1.494；范围：0.60-2.50）。采用 1.09×10(-3) mm(2) /s 的 ADC 值阈值，DWI 在识别该组淋巴结转移方面的敏感性为 94.7%，特异性为 91.7%，准确性为 93.0%。
从这些初步数据来看，DWI 在鉴别乳腺癌患者腋窝转移性和良性淋巴结方面似乎是一种很有前途的方法。
