title: Visualization of ovarian tumors using 3T MR imaging: diagnostic effectiveness and difficulties.
abstract: OBJECTIVE
  We evaluated the diagnostic effectiveness of magnetic resonance (MR) imaging at 3 tesla to visualize ovarian tumors and problems associated with its use.
  
  
  METHODS
  From the records of 423 consecutive women who underwent pelvic MR imaging using a 3T system from April 2009 to June 2010, we analyzed 50 continuous cases of ovarian tumors proved by histopathology. We evaluated visualization of these tumors for image quality and artifacts using 5-point scales. For qualitative assessment, we scored overall image quality (1, poor, to 5, excellent), degree of conviction regarding the diagnosis (1, undiagnosable, to 5, diagnosable with high certainty), and 4 representative artifacts (penetrating, chemical shift, motion, and susceptibility artifact) (1, severe, to 5, little degradation). We also retrospectively reviewed the diagnostic features of the ovarian tumors and preoperative diagnostic accuracy. For quantitative assessment, we determined tumor size and ADC value.
  
  
  RESULTS
  Overall quality score was scored 4.9±0.5, and conviction regarding diagnosis was 4.9±0.3. Artifacts caused little degradation in most cases: penetrating, 4.8±0.5; chemical shift, 4.3±0.5; motion, 4.6±0.6; and susceptibility, 3.8±0.9. Preoperative diagnostic accuracy was 92% (sensitivity 94.7%, specificity 90.3%). Mean tumor diameter was 88.3±61 mm. The mean ADC value was 1.04±0.3 in malignant tumors and 1.15±0.5 (×10⁻⁶ mm²/s) in benign tumors.
  
  
  CONCLUSIONS
  The quality of ovarian tumor images obtained with a 3T MR imaging system is adequate for diagnosis, with only slight degradation from penetrating or susceptibility artifacts.
authors.affiliation: Department of Radiology, Nara Prefectural Nara Hospital, Nara, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Uehara
authors.forename: Junko
authors.initials: J
authors.lastname: Takahama
authors.forename: Nagaaki
authors.initials: N
authors.lastname: Marugami
authors.forename: Aki
authors.initials: A
authors.lastname: Takahashi
authors.forename: Megumi
authors.initials: M
authors.lastname: Takewa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Itoh
authors.forename: Satoru
authors.initials: S
authors.lastname: Kitano
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Kichikawa
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015588:Observer Variation; D010051:Ovarian Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity