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
- 323 Downloads
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).
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.
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.
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.
• 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.
KeywordsUterine fibroid Magnetic resonance imaging Scaled signal intensity Focused ultrasound Ablation
The authors thank Cha Bok Chung and Eun Joo Baek for their help in managing the patients during MRgFUS treatment. We also thank Suk Hee Kim and Seon Ha Yun for their help in preparing the manuscript.
The scientific guarantor of this publication is Professor Sang-Wook Yoon. The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article. The authors state that this work has not received any funding. One of the authors has significant statistical expertise. Institutional Review Board approval was obtained.
Written informed consent was waived by the Institutional Review Board. Methodology: retrospective, observational study, performed at one institution.
- 4.Yoon SW, Kim KA, Whang YY, Lee C, Cha SH, Lee SY et al (2008) Magnetic resonance imaging-guided focused ultrasound surgery for uterine fibroids: Initial experience in Korea. Korean J Obstet and Gynecol 51:5Google Scholar
- 5.Funaki K, Fukunishi H, Funaki T, Sawada K, Kaji Y, Maruo T (2007) Magnetic resonance-guided focused ultrasound surgery for uterine fibroids: relationship between the therapeutic effects and signal intensity of preexisting T2-weighted magnetic resonance images. Am J Obstetrics Gynecol 196:184 e1-6CrossRefGoogle Scholar
- 10.Oguchi O, Mori A, Kobayashi Y, Horiuchi A, Nikaido T, Fujii S (1995) Prediction of histopathologic features and proliferative activity of uterine leiomyoma by magnetic resonance imaging prior to GnRH analogue therapy: correlation between T2-weighted images and effect of GnRH analogue. J Obstet Gynaecol 21:107–117CrossRefGoogle Scholar