title: Scaled signal intensity of uterine fibroids based on T2-weighted MR images: a potential objective method to determine the suitability for magnetic resonance-guided focused ultrasound surgery of uterine fibroids.
abstract: OBJECTIVE
  Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) is a non-invasive method to treat uterine fibroids. To help determine the patient suitability for MRgFUS, we propose a new objective measure: the scaled signal intensity (SSI) of uterine fibroids in T2 weighted MR images (T2WI).
  
  
  METHODS
  Forty three uterine fibroids in 40 premenopausal women were included in this retrospective study. SSI of each fibroid was measured from the screening T2WI by standardizing its mean signal intensity to a 0-100 scale, using reference intensities of rectus abdominis muscle (0) and subcutaneous fat (100). Correlation between the SSI and the non-perfused volume (NPV) ratio (a measure for treatment success) was calculated.
  
  
  RESULTS
  Pre-treatment SSI showed a significant inverse-correlation with post treatment NPV ratio (p < 0.05). When dichotomizing NPV ratio at 45 %, the optimal cut off value of the SSI was found to be 16.0.
  
  
  CONCLUSIONS
  A fibroid with SSI value 16.0 or less can be expected to have optimal responses. The SSI of uterine fibroids in T2WI can be suggested as an objective parameter to help in patient selection for MRgFUS.
  
  
  CONCLUSIONS
  • Signal intensity of fibroid in MR images predicts treatment response to MRgFUS. • Signal intensity is standardized into scaled form using adjacent tissues as references. • Fibroids with SSI less than 16.0 are expected to have optimal responses.
authors.affiliation: Comprehensive Gynecologic Cancer Center, CHA Bundang Medical Center, CHA University, Gyunggi-do, Republic of Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Diagnostic Radiology, CHA Bundang Medical Center, CHA University, 351, Yatap-dong, Bundang-gu, Sungnam-si, Gyunggi-do, Republic of Korea, 463-712. jansons@cha.ac.kr.
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Yoon
authors.affiliation: InSightec Ltd., Haifa, Israel.
authors.forename: Amit
authors.initials: A
authors.lastname: Sokolov
mesh_terms: D000328:Adult; D005260:Female; D057086:High-Intensity Focused Ultrasound Ablation; D006801:Humans; D007889:Leiomyoma / Q000473:pathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D053783:Magnetic Resonance Imaging, Interventional; D018579:Patient Selection; D017697:Premenopause; D012189:Retrospective Studies; D016896:Treatment Outcome; D014594:Uterine Neoplasms / Q000473:pathology* / Q000601:surgery*
keywords: Ablation; Focused ultrasound; Magnetic resonance imaging; Scaled signal intensity; Uterine fibroid