MR-IMAGING OF CHEST-WALL LESIONS

To assess the magnetic resonance (MR) imaging findings of chest wall lesions, images from 45 patients were reviewed by two experienced chest radiologists. The study included 14 benign and 31 malignant lesions. Images were obtained on 1.5-T imagers with use of conventional T1-, proton-density, and T2-weighted sequences in transverse, coronal, and sagittal imaging planes. Where appropriate, motion artifact was minimized with respiratory compensation, spatial presaturation, flow compensation, and cardiac gating. Twelve of 14 benign lesions showed well-defined, smooth margins compared with 10 of 31 malignant lesions (P < .05). The remaining 21 malignant lesions had irregular or ill-defined margins and evidence of muscle, bone, or vascular invasion. A capsule or pedicle was seen only in benign lesions. Characteristic MR signal intensity was seen in all four lipomas and in the only arteriovenous malformation. The remaining benign and malignant lesions showed nonspecific signal intensity characteristics. MR imaging allows the detection of muscle, bone, or vascular invasion by chest wall tumors. However, as in other musculoskeletal regions, MR imaging does not allow confident distinction of benign from malignant chest wall lesions.