Nodal Metastasis in Non–Small Cell Lung Cancer: Accuracy of 3.0-T MR Imaging

Abstract

To prospectively evaluate the diagnostic accuracy of 3.0-T magnetic resonance (MR) imaging in the detection of non-small cell lung cancer nodal metastasis, with histopathologic analysis as the reference standard. Institutional review board approval and informed consent were obtained. From July 2005 to May 2006, 113 patients (91 men, 22 women; age range, 34-82 years; mean age, 61 years) with non-small cell lung cancer underwent thoracic 3.0-T MR imaging followed by surgery or mediastinoscopy. The lymph node-to-tumor ratios (LTRs) of signal intensity and nodal morphologic characteristics (such as eccentric cortical thickening or obliteration of the fatty hilum) were assessed on T2-weighted triple-inversion black-blood fast spin-echo images. Nodal short-axis diameter was assessed on T1-weighted three-dimensional fast field-echo images. Receiver operating characteristic and multivariate logistic regression analyses were used for statistical evaluation. The cutoff value (LTR > 0.84) proved to be most appropriate (area under the receiver operating characteristic curve = 0.735, P < .001) in the detection of a nodal metastasis. Of the various parameters examined, morphologic characteristics appeared to be the most significant (P < .001) parameters for depicting a malignant node (multivariate logistic regression analyses; odds ratio, 7.5). Nodal morphology was analyzed, and diagnostic sensitivity, specificity, and accuracy were 53% (39 of 74 nodal stations), 91% (453 of 496 nodal stations), and 86% (492 of 570 nodal stations), respectively. Morphologic details of lymph nodes on T2-weighted triple-inversion black-blood fast spin-echo MR images are significant for detection of mediastinal or hilar nodal metastasis at 3.0-T MR imaging.