Purpose:To evaluate the accuracy of four MR sequences used as part of a whole-body MRI protocol to detect pulmonary lesions in cancer patients.
Materials and Methods:A total of 31 oncology patients were imaged in a 1.5T MR scanner (Magnetom Avanto; Siemens Medical Solutions, Germany) for whole-body staging. MR chest imaging included: axial and coronal T2-weighted (T2w)-short-tau inversion-recovery (STIR), axial T2w turbo spin-echo (TSE), and contrast-enhanced (CE) three-dimensional (3D) volumetric interpolated breathhold examination (VIBE). Multidetector computed tomography (MDCT) of the thorax served as the reference standard. The MDCT and MR images were evaluated independently by two radiologists. Comparative analysis was performed per lesion, per lobe, and per patient. Sensitivity, specificity, and predictive values were determined.Results: Compared to MDCT that detected 268 pulmonary lesions ranging from 2 to 75 mm in diameter, the MR sensitivities were 91.1%, 92.5%, 90.8%, and 87.3% for the coronal STIR, the axial STIR, the axial T2w-TSE, and the axial CE 3D-VIBE, respectively. Undetected pulmonary lesions were either calcified or smaller than 10 mm in the axial diameter. With coronal STIR, six false-positive findings were detected; with axial STIR, 14 were detected; with axial T2w-TSE, 10 were detected; and with 3D-VIBE, seven were detected.
Conclusion:Pulmonary MRI is feasible as part of a wholebody MRI protocol. In our study, STIR images achieved high accuracy compared to chest MDCT for pulmonary lesions of 3 mm in size or larger. IN MALIGNANT DISEASES, therapeutic options as well as the patient prognosis strongly depend on the tumor stage. Following recent developments in MR hardware, such as faster MR gradients, moving table technology, and multielement coil designs, MRI of the entire body in a single session is being increasingly utilized as an attractive alternative to computed tomography (CT) for whole-body tumor staging without exposing the patients to radiation (1,2). Due to its high soft-tissue contrast, the diagnostic accuracy of MRI is recognized in the musculoskeletal system, the head, the neck, and the abdomen (2-5). In the thorax, MRI has been used to assess tumors invading the chest wall and for mediastinal and cardiac tumors (6,7). For pulmonary imaging, MR is still perceived as inferior to multidetector CT (MDCT). However, as pulmonary lesion detection is an integral part of whole-body cancer imaging studies, a limited diagnostic accuracy in pulmonary staging could severely hamper the value of whole-body MRI of cancer patients.Recent MRI studies reported encouraging results for the detection of pulmonary nodules larger than 5-8 mm in diameter using single fast breathhold (BH) MR sequences in a limited number of patients (4,5,8 -11). Schroeder et al (11), for example, compared the diagnostic performance of a combined set of axial and coronal half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences with MDCT in a series of 30 patients and found a sensitivity for the detection ...