title: Incidentally found and unexpected tumors discovered by MRI examination for temporomandibular joint arthrosis.
abstract: We examined the frequency of incidentally found or unexpected tumors discovered at the time of magnetic resonance imaging (MRI) examinations in the temporomandibular joint (TMJ) region for patients with suspicion of TMJ arthrosis. Five MR images (T1-weighted transverse scout image and proton density and T2-weighted oblique sagittal images at the open and closed mouth) were acquired. In 2776 MRI examinations of TMJ arthrosis, two tumors were discovered. They consisted of an adenoid cystic carcinoma in the deep portion of the parotid gland, and a malignant tumor extending from the infratemporal fossa to the parapharyngeal space. The rate of incidentally founded or unexpected tumors in TMJ examinations was low (0.072%), but the two tumors found were malignant tumors, and therefore, scout image should be carefully examined, not only used for positing the slice.
authors.affiliation: Department of Oral and Maxillofacial Radiology, Field of Tumor Biology, Graduate School of Medicine and Dentistry, Okayama University, 2-5-1, Shikata-cho, Okayama 700-8525, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Yanagi
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Asaumi
authors.forename: Yuu
authors.initials: Y
authors.lastname: Maki
authors.forename: Jun
authors.initials: J
authors.lastname: Murakami
authors.forename: Miki
authors.initials: M
authors.lastname: Hisatomi
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Matsuzaki
authors.forename: Hironobu
authors.initials: H
authors.lastname: Konouchi
authors.forename: Yosutoshi
authors.initials: Y
authors.lastname: Honda
authors.forename: Kanji
authors.initials: K
authors.lastname: Kishi
mesh_terms: D000368:Aged; D001168:Arthritis / Q000175:diagnosis* / Q000453:epidemiology; D003528:Carcinoma, Adenoid Cystic / Q000175:diagnosis; D015838:Chondromatosis, Synovial / Q000175:diagnosis; D006801:Humans; D015994:Incidence; D007564:Japan; D008279:Magnetic Resonance Imaging; D008297:Male; D008339:Mandibular Neoplasms / Q000175:diagnosis; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging / Q000473:pathology; D010307:Parotid Neoplasms / Q000175:diagnosis; D010610:Pharyngeal Neoplasms / Q000175:diagnosis; D011859:Radiography; D012189:Retrospective Studies; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging*; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis* / Q000453:epidemiology