title: Diversity in size and signal intensity in multilocular cystic ovarian masses: new parameters for distinguishing metastatic from primary mucinous ovarian neoplasms.
abstract: OBJECTIVE
  To differentiate primary mucinous ovarian neoplasms from metastatic ones with MR using diversity in size and signal intensity of multilocular cystic masses.
  
  
  METHODS
  Twenty-eight cases of primary malignant or borderline mucinous malignant neoplasms and 14 metastatic ovarian tumors were retrospectively reviewed. We analyzed whether the tumor was unilateral or bilateral, the diversity in the size and signal intensity of each loculus in multilocular tumors, namely the size ratio of the smallest/largest loculus (size diversity ratio), and the standard deviation of the signal intensity at the level with the most varying signal on T2-weighted images within tumors (signal diversity ratio). We performed statistical analysis using the Mann-Whitney U-test.
  
  
  RESULTS
  Bilateral tumors were more commonly observed among metastatic tumors than primary mucinous tumors (2/28 in primary versus 11/14 in metastatic, P < 0.01). The size diversity ratio was higher in primary mucinous tumors than in metastatic tumors (mean, 50.2 versus 23.2; P < 0.01). The signal diversity ratio was also higher in primary mucinous tumors than in metastatic tumors (334.3 versus 231.2; P < 0.01).
  
  
  CONCLUSIONS
  Bilateral tumors were more common among metastatic tumors, which tended to be composed of cysts of uniform sizes and signal intensities compared with those of primary mucinous tumors.
authors: Department of Radiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors: Yumiko Oishi
authors: YO
authors: Tanaka
authors: Satoshi
authors: S
authors: Okada
authors: Toyomi
authors: T
authors: Satoh
authors: Koji
authors: K
authors: Matsumoto
authors: Akinori
authors: A
authors: Oki
authors: Tsukasa
authors: T
authors: Saida
authors: Hiroyuki
authors: H
authors: Yoshikawa
authors: Manabu
authors: M
authors: Minami
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003936:Diagnosis, Computer-Assisted; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010048:Ovarian Cysts / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D010051:Ovarian Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D012372:ROC Curve; D012189:Retrospective Studies
keywords: magnetic resonance imaging; metastatic; mucinous adenocarcinoma; mucinous ovarian neoplasms; neoplasms; ovary