title: Diffusion-weighted MRI of epithelial ovarian cancers: correlation of apparent diffusion coefficient values with histologic grade and surgical stage.
abstract: OBJECTIVE
  The purpose of this article is to correlate the apparent diffusion coefficient (ADC) values of epithelial ovarian cancers with histologic grade and surgical stage.
  
  
  METHODS
  We enrolled 43 patients with pathologically proven epithelial ovarian cancers for this retrospective study. All patients underwent preoperative pelvic magnetic resonance imaging (MRI) including diffusion-weighted images with b value of 0 and 1000 s/mm2 at 3.0-T unit. The mean ADC values of the solid portion of the tumor were measured and compared among different histologic grades and surgical stages.
  
  
  RESULTS
  The mean ADC values of epithelial ovarian cancers differed significantly between grade 1 (well-differentiated) and grade 2 (moderately-differentiated) (P=0.013) as well as between grade 1 and grade 3 (poorly-differentiated) (P=0.01); however, no statistically significant difference existed between grade 2 and grade 3 (P=0.737). The receiver-operating characteristic analysis indicated that a cutoff ADC value of less than or equal to 1.09×10(-3)mm2/s was associated with 94.4% sensitivity and 85.7% specificity in distinguishing grade 1 and grade 2/3 cancer. The difference in mean ADC values was statistically significant for early stage (FIGO stage I) and advanced stage (FIGO stage II-IV) cancer (P=0.011). The interobserver agreement for the mean ADC values of epithelial ovarian cancers was excellent.
  
  
  CONCLUSIONS
  The mean ADC values of the solid portion of epithelial ovarian cancers negatively correlated to histologic grade and surgical stage. The mean ADC values may be useful imaging biomarkers for assessment of tumor grade of epithelial ovarian cancer.
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea. Electronic address: fromentin@naver.com.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Oh
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea. Electronic address: serha@catholic.ac.kr.
authors.forename: Sung Eun
authors.initials: SE
authors.lastname: Rha
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea. Electronic address: hiohsn@catholic.ac.kr.
authors.forename: Soon Nam
authors.initials: SN
authors.lastname: Oh
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea. Electronic address: digirave@kmle.com.
authors.forename: Michael Yong
authors.initials: MY
authors.lastname: Park
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea. Electronic address: jybyun@catholic.ac.kr.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Byun
authors.affiliation: Department of Hospital Pathology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea. Electronic address: klee@catholic.ac.kr.
authors.forename: Ahwon
authors.initials: A
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D000077216:Carcinoma, Ovarian Epithelial; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D009375:Neoplasms, Glandular and Epithelial / Q000473:pathology*; D010051:Ovarian Neoplasms / Q000473:pathology*; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers
keywords: Apparent diffusion coefficient; Diffusion-weighted imaging; Epithelial ovarian cancer; Histologic grade; MRI