Book Review MRI: Central nervous system Edited by Walter Kucharczyk. Approximately 300 pp., illustrated. Philadelphia, J.B. Lippincott/Gower Medical, 1990. $79.50. MRI: Musculoskeletal system Edited by Javier Beltran. Approximately 325 pp., illustrated. Philadelphia, J.B. Lippincott/Gower Medical, 1990. $79.50.