title: Conventional MRI findings for predicting submandibular pleomorphic adenoma.
abstract: BACKGROUND
  Although pleomorphic adenomas account for over 90% of all benign submandibular gland tumors, the imaging features of submandibular pleomorphic adenomas have not been reported in a large number of cases.
  
  
  OBJECTIVE
  To assess the conventional magnetic resonance imaging (MRI) findings for predicting the submandibular pleomorphic adenoma.
  
  
  METHODS
  MR studies of 42 pleomorphic adenomas and 28 other types of tumor were reviewed. MR images were assessed for the presence of hyperintense areas on T2-weighted images (first sign), a well-defined margin (second sign), and presence of crescent-shaped compression of the ipsilateral normal submandibular gland (third sign).
  
  
  RESULTS
  For identifying submandibular pleomorphic adenoma, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 97.6%, 50.0%, 74.5%, 93.3%, and 78.6% for the first sign, 95.2%, 46.4% 72.7%, 86.7%, and 75.7% for the second sign, and 23.8%, 100%, 86.7%, 46.7%, and 54.3% for the third sign, respectively. Combining the first and second findings achieved to 85.7% specificity and 90.9% accuracy.
  
  
  CONCLUSIONS
  Although non-specific, submandibular pleomorphic adenomas usually have hyperintense areas on T2-weighted images and well-defined margins. In addition, crescent-shaped compression of the ipsilateral normal gland seems to represent a highly specific sign.
authors: Department of Radiology, Kinki University School of Medicine, Osaka kashiwaginobuo@yahoo.co.jp.
authors: Nobuo
authors: N
authors: Kashiwagi
authors: Department of Radiology, Kinki University School of Medicine, Osaka.
authors: Takamichi
authors: T
authors: Murakami
authors: Department of Diagnostic Radiology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka.
authors: Katsuyuki
authors: K
authors: Nakanishi
authors: Department of Pathology, Kinki University School of Medicine, Osaka.
authors: Osamu
authors: O
authors: Maenishi
authors: Department of Radiology, Nara Hospital, Kinki University Faculty of Medicine, Osaka.
authors: Kaoru
authors: K
authors: Okajima
authors: Department of Radiology, Kinki University School of Medicine, Osaka.
authors: Hiroto
authors: H
authors: Takahashi
authors: Department of Diagnostic Radiology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka.
authors: Mio
authors: M
authors: Sakai
authors: Department of Pathology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka.
authors: Yasuhiko
authors: Y
authors: Tomita
authors: Department of Otolaryngology, Kinki University School of Medicine, Osaka.
authors: Kyoichi
authors: K
authors: Terao
authors: Department of Radiology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors: Noriyuki
authors: N
authors: Tomiyama
mesh_terms: D008949:Adenoma, Pleomorphic / Q000175:diagnosis*; D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013365:Submandibular Gland Neoplasms / Q000175:diagnosis*
keywords: Head/neck; MR imaging; salivary glands