[en] The value of MRI was compared with that of US with respect to noninvasiveness, indications, time of examination, artifacts, and potential of differential diagnosis of masses in 44 patients with surgery- or biopsy-proven ovarian masses. MRI was superior in the qualitative diagnosis of cystic masses because of high contrast resolution. It had more sensitivity to blood components than US. A major disadvantage of MRI was longer time required for examination. (Namekawa, K.)