Hounsfield Number Measurement after a Uterine Fibroid Embolization: Significance as a Predictive Factor of Embolization Success

ABSTRACT

PURPOSE: To assess the usefulness of the Hounsfield number, measured by a non-contrast enhanced pelvic CT, after a uterine artery embolization as an index of the successful outcome of a uterine fibroid embolization (UFE). MATERIALS AND METHODS: The study subjects included 15 women (age range 28-49 years, mean age 36.4 years) diagnosed with symptomatic uterine myomas and seen from March 2003 to August 2005. A non-contrast enhanced pelvic CT scan was performed six hours after a uterine artery embolization. The global and maximal CT numbers were measured for each myoma. In addition, a pelvic MRI was performed to measure the volume of each myoma prior to and 6 months after the UFE. The relationship between fibroid volume reduction and the global CT number were prospectively analysed. RESULTS: The mean global CT number was 91.25 HU in Group I and 40.8 HU in Group II. Further, the mean fibroid volume reduction rate was 73% in Group I and 10% in Group II (p < 0.05). CONCLUSION: The global CT number measured by a non-contrast enhanced pelvic CT is a useful predictive factor of a successful uterine fibroid embolization.