3-T MRI: Usefulness for evaluating primary lung cancer and small nodules in lobes not containing primary tumors

OBJECTIVE. The purpose of this study was to evaluate the diagnostic performance of 3-T MRI in the detection and characterization of primary non-small cell lung cancer and of small nodules in lobes not containing primary tumors. MATERIALS AND METHODS. From July 2005 to May 2006, 127 patients (99 men, 28 women; mean age, 63 years) with histopathologically proven non-small cell lung cancer underwent both CT and MRI of the chest. Transverse MR images were obtained with T1-weighted 3D turbo field-echo and T2- weighted triple inversion black blood turbo spin-echo sequences on a 3-T MRI system. Two chest radiologists assessed CT images and then MR images. The morphologic features of lung cancer and the detectability of small nodules in lobes not containing primary tumors on MR images were compared with the findings on CT images, which were the reference standard. RESULTS. The morphologic characteristics of primary cancer found on both T1- and T2-weighted images corresponded to those on CT images. The overall rates of detection of nodules in lobes not containing primary tumors were 57% (184 of 323 nodules) and 56% (180 of 323 nodules) on T1- and T2-weighted images, respectively (p = 0.64). In terms of detection of noncalcified nodules 5-10 mm in diameter, both T1- and T2-weighted images had a detection rate of 92% (48 of 52 nodules) (p = 1.00). CONCLUSION. Both T1-weighted 3D turbo field-echo and T2-weighted triple inversion black blood turbo spin-echo 3-T MR images depict clinically significant small (5-10 mm in diameter) noncalcified pulmonary nodules nearly as well as do CT scans.