Associations between pelvic MRI findings and symptom presence in uterine leiomyoma and adenomyosis: a quantitative analysis

Abstract

To evaluate the relationship between pelvic MRI findings and symptom presence in patients with leiomyoma and adenomyosis, and to determine whether these imaging parameters are independently associated with the presence of symptoms. This single-center retrospective study enrolled 150 patients who underwent pelvic MRI and were stratified into three groups based on pathological diagnosis: leiomyoma only ( n  = 75), adenomyosis only ( n  = 36), and concurrent pathology ( n  = 39). Leiomyoma assessment included International Federation of Gynecology and Obstetrics (FIGO) classification, maximum diameter, cavity distortion, and apparent diffusion coefficient (ADC) values; for adenomyosis, junctional zone (JZ) thickness and involvement pattern served as primary parameters. Composite MRI burden scores were constructed for each pathology. Imaging features independently associated with symptom presence were identified by binary logistic regression, and model discrimination was assessed with internal validation by bootstrap resampling. Symptom prevalence differed substantially across groups — 64.0% in the leiomyoma group, 72.2% in the adenomyosis group, and 97.4% in patients with concurrent pathology ( p  < 0.001). Each 1 mm increase in JZ thickness raised the odds ratio (OR) of symptoms 1.31-fold in the adenomyosis group (OR = 1.31; 95% confidence interval [CI]: 1.08–1.58; p  = 0.006), with JZ thickness correlating with pelvic pain at r  = 0.61. FIGO type 0–2 location was the imaging feature most strongly associated with abnormal uterine bleeding (AUB) among leiomyoma patients (OR = 6.82; 95% CI: 2.87–16.21; p  < 0.001). ADC values were markedly lower in symptomatic leiomyomas (0.91 vs. 1.14 × 10⁻³ mm²/s; p  < 0.001). The apparent area under the curve (AUC) was 0.809 for the symptom model and 0.821 for the AUB model, with optimism-corrected values of 0.785 and 0.796, respectively, on bootstrap internal validation. Pelvic MRI findings in leiomyoma and adenomyosis are independently associated with the presence of symptoms, with JZ thickness, leiomyoma localization relative to the endometrial cavity, lesion size, and cavity distortion showing the strongest associations. Because these associations were derived and tested within a single cross-sectional sample, they should be regarded as hypothesis-generating and require prospective, externally validated confirmation before they can guide treatment decisions.