Left, Soft-tissue swelling is adjacent to the radial and ulnar styloid processes. The swelling obliterates normal fascial lines. Irregularity of the tip of the ulnar styloid process results from early erosive change (arrow). Right, Magnification of the ulnar styloid process shows erosive changes medially and more clearly at the tip. From Berens DL, Lin R. Roentgen Diagnosis of Rheumatoid Arthritis, 1969. Courtesy of Charles C. Thomas, Publisher, Ltd., Springfield, Illinois.