Xu Liang, Tian Jiakai, Liu Yuhui, Li Chuanfu
Department of Radiology, Shandong Cancer Hospital, Shandong Academy of Medical Sciences, Ji'nan, P.R. China.
J Magn Reson Imaging. 2014 Jul;40(1):200-5. doi: 10.1002/jmri.24343. Epub 2013 Oct 29.
To prospectively evaluate the accuracy of diffusion-weighted (DW) magnetic resonance (MR) imaging with background signal suppression (MR-DWIBS) for detecting mediastinal lymph node metastasis of nonsmall-cell lung cancer (NSCLC).
MR-DWIBS was performed in 42 consecutive patients (27 men, 15 women; age range, 42-78 years; median age, 55 years) with histologically proven NSCLC. The visualization rate of metastatic lymph node (MLN) and benign lymph node (BLN) of enlarged lymph nodes (ELN) and normal-sized lymph nodes (NLN) was compared by using a chi-square test or Fisher's exact test on a per-nodal basis. Apparent diffusion coefficient (ADC) of MLN and BLN was measured and compared by using two-tailed unpaired Student's t-test. Receiver operating characteristic (ROC) analysis was used to assess the overall diagnostic accuracy of ADC for ELN and NLN. The optimal cutoff value was determined and the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy was calculated.
Thirty-five out of 119 lymph resected nodes were confirmed to be metastatic by histologic examination. The visualization rate of MLN was significantly higher than that of BLN for ELN (P < 0.001) and for NLN (χ(2) = 7.506, P = 0.006). For both ELN and NLN, ADC of MLN was significantly lower than that of BLN (t = -5.380, P < 0.001 and t = -6.435, P < 0.001). ADC was significant for detection of MLN for both ELN (Az = 0.975, P < 0.001) and NLN (Az = 0.919, P < 0.001). For NLN, the optimal cutoff value of ADC was 2.04 mm(2)/s, where the sensitivity, specificity, PPV, NPV, and accuracy were 75.0%, 90.9%, 66.7%, 93.8%, and 87.8%, respectively.
MR-DWIBS may be clinically useful to visually detect mediastinal lymph nodes and ADC measurement can aid in malignant node discrimination.
前瞻性评估背景信号抑制扩散加权磁共振成像（MR-DWIBS）检测非小细胞肺癌（NSCLC）纵隔淋巴结转移的准确性。
对42例经组织学证实为NSCLC的连续患者（27例男性，15例女性；年龄范围42 - 78岁；中位年龄55岁）进行MR-DWIBS检查。在逐个淋巴结基础上，采用卡方检验或Fisher精确检验比较肿大淋巴结（ELN）和正常大小淋巴结（NLN）中转移淋巴结（MLN）和良性淋巴结（BLN）的显示率。测量并采用双尾非配对学生t检验比较MLN和BLN的表观扩散系数（ADC）。采用受试者操作特征（ROC）分析评估ADC对ELN和NLN的总体诊断准确性。确定最佳截断值并计算敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）和准确性。
119个切除的淋巴结中，35个经组织学检查证实为转移。ELN中MLN的显示率显著高于BLN（P < 0.001），NLN中也是如此（χ(2) = 7.506，P = 0.006）。对于ELN和NLN，MLN的ADC均显著低于BLN（t = -5.380，P < 0.001和t = -6.435，P < 0.001）。ADC对ELN（Az = 0.975，P < 0.001）和NLN（Az = 0.919，P < 0.001）的MLN检测均具有显著性。对于NLN，ADC的最佳截断值为2.04 mm(2)/s，此时敏感性、特异性、PPV、NPV和准确性分别为75.0%、90.9%、66.7%、93.8%和87.8%。
MR-DWIBS在临床上可能有助于直观检测纵隔淋巴结，ADC测量有助于鉴别恶性淋巴结。
