title: Principles of ultrasonography.
mesh_terms: D000328:Adult; D000368:Aged; D002648:Child; D003884:Dermoid Cyst / Q000175:diagnosis; D005260:Female; D005313:Fetal Death / Q000175:diagnosis; D006801:Humans; D011247:Pregnancy; D011258:Pregnancy Tests; D011272:Pregnancy, Multiple; D014427:Twins; D014465:Ultrasonics; D014463:Ultrasonography