MR-IMAGING OF CHEST-WALL LESIONS

To assess the magnetic resonance (MR) imaging findings of chest wall l esions, 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-, pr oton-density, and T2-weighted sequences in transverse, coronal, and sa gittal imaging planes. Where appropriate, motion artifact was minimize d with respiratory compensation, spatial presaturation, flow compensat ion, and cardiac gating. Twelve of 14 benign lesions showed well-defin ed, smooth margins compared with 10 of 31 malignant lesions (P < .05). The remaining 21 malignant lesions had irregular or ill-defined margi ns and evidence of muscle, bone, or vascular invasion. A capsule or pe dicle was seen only in benign lesions. Characteristic MR signal intens ity was seen in all four lipomas and in the only arteriovenous malform ation. The remaining benign and malignant lesions showed nonspecific s ignal intensity characteristics. MR imaging allows the detection of mu scle, bone, or vascular invasion by chest wall tumors. However, as in other musculoskeletal regions, MR imaging does not allow confident dis tinction of benign from malignant chest wall lesions.