title: Apparent diffusion coefficient of uterine leiomyoma as a predictor of the potential response to uterine artery embolization.
abstract: OBJECTIVE
  To determine the utility of the apparent diffusion coefficient (ADC) of uterine leiomyoma for prediction of the potential response to uterine artery embolization (UAE).
  
  
  METHODS
  This prospective study included 49 patients with uterine leiomyomas who underwent diffusion-weighted magnetic resonance (MR) imaging before UAE between May 2011 and January 2012. All patients also underwent 3-month follow-up MR imaging after UAE. Using conventional and diffusion-weighted MR imaging sequences, 72 uterine leiomyomas ≥ 3 cm were prospectively evaluated. The volume of each leiomyoma was calculated, and quantitative measurement of ADC was performed. Regression analysis was used to evaluate the relationship between ADC and volumetric response after UAE. Receiver operating characteristic curve analysis was performed to determine the sensitivity and specificity of ADC for prediction of the potential response to UAE. Interclass correlation coefficient analysis was used to assess interobserver variability between two radiologists.
  
  
  RESULTS
  Volume reduction rates of leiomyomas after UAE ranged from 0.2%-89.1% (mean, 44.1%). ADC ranged from 0.559 × 10(-3) mm(2)/s to 1.814 × 10(-3) mm(2)/s (mean, 1.170 × 10(-3) mm(2)/s). ADC was statistically significantly related to volumetric response of leiomyomas (P = .014). Using a threshold of 1.092 × 10(-3) mm(2)/s, the sensitivity and specificity of ADC for prediction of > 50% volume reduction of the leiomyoma after UAE were 82.6% and 52.3%, respectively. Using a threshold of 1.023 × 10(-3) mm(2)/s, the sensitivity and specificity of ADC for prediction of < 30% volume reduction were 80.8% and 33.3%, respectively. The interclass correlation coefficient for measuring ADC of uterine leiomyomas between two radiologists was 0.98.
  
  
  CONCLUSIONS
  ADC of uterine leiomyomas was significantly related to the volume reduction after UAE. ADC may be useful in predicting the potential response to UAE. A high ADC of the uterine leiomyoma may be associated with a greater volume reduction after UAE.
authors.affiliation: Department of Radiology, Jeju National University Hospital, Jejudo, Republic of Korea.
authors.forename: Mu Sook
authors.initials: MS
authors.lastname: Lee
authors.forename: Man Deuk
authors.initials: MD
authors.lastname: Kim
authors.forename: Dae Chul
authors.initials: DC
authors.lastname: Jung
authors.forename: Myungsu
authors.initials: M
authors.lastname: Lee
authors.forename: Jong Yun
authors.initials: JY
authors.lastname: Won
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Park
authors.forename: Do Yun
authors.initials: DY
authors.lastname: Lee
authors.forename: Kwang-Hun
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000328:Adult; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007889:Leiomyoma / Q000473:pathology*; D008875:Middle Aged; D015588:Observer Variation; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D047368:Tumor Burden; D055357:Uterine Artery Embolization / Q000379:methods*; D014594:Uterine Neoplasms / Q000473:pathology* / Q000628:therapy*
keywords: ADC; DW; ROC; UAE; VRR; apparent diffusion coefficient; diffusion-weighted; receiver operating characteristic; uterine artery embolization; volume reduction rate