MR Reproducibility in the Assessment of Uterine Fibroids for Patients Scheduled for Uterine Artery Embolization

Magnetic resonance imaging (MRI) is increasingly applied in the evaluation of uterine fibroids. However, little is known about the reproducibility of MRI in the assessment of uterine fibroids. This study evaluates the inter- and intraobserver variation in the assessment of the uterine fibroids and concomitant adenomyosis in women scheduled for uterine artery embolization (UAE). Forty patients (mean age: 44.5 years) with symptomatic uterine fibroids who were scheduled for UAE underwent T₁- and T₂-weighted MRI. To study inter- and intraobserver agreement 40 MR images were evaluated independently by two observers and reevaluated by both observers 4 months later. Inter- and intraobserver agreement was calculated using Cohen’s κ statistic and intraclass correlation coefficient for categorical and continuous variables, respectively. Inter-observer agreement for uterine volumes (κ = 0.99, p < 0.0001), dominant fibroid volumes (κ = 0.98, p ≤ 0.0001), and number of fibroids (κ = 0.88; CI, 0.77–0.93; p < 0.0001) was excellent. For the T₁- and T₂-weighted signal intensity of the dominant fibroid there was good agreement between the observers (87%; 95% CI, 71.9%–95.6%) and the intraobserver agreement was good for observer A (95%; 95% CI, 83.1%–99.4%) and moderate for observer B (κ = 0.47). The interobserver agreement with respect to the presence of adenomyosis was good (κ = 0.73, p < 0.0001), while both intraobserver agreements were fair to moderate (observer A, κ = 0.55, p = 0.0003; and observer B, κ = 0.66, p < 0.0001). In conclusion, MRI criteria used for the selection of suitable UAE patients show good inter- and intraobserver reproducibility.