Unlabeled images, for comparison: T2-weighted MR in the sagittal plane without fat saturation

yellow-first rib; green-brachial plexus; red-subclavian artery; blue-subclavian vein; orange-anterior scalene muscle; purple-middle scalene muscle; lavender-tumor

There is a large right apical lung mass, a Pancoast tumor, which is involving the lower portion of the brachial plexus and abutting the subclavian artery.