Evaluation of Digital Image Enhancement Methods for MRI Visualization of Small Uterine Fibroids: An Inter-Reader Agreement Study

Magnetic Resonance Imaging (MRI) is a crucial imaging modality for evaluating gynecological pelvic disorders particularly those affecting the uterus, such as uterine fibroids. However, visualizing small uterine fibroids (less than 3 cm in diameter) can be challenging due to poor lesion conspicuity, image noise and low local contrast. This study evaluated the impact of digital image enhancement techniques on the visibility of small uterine fibroids in MRI images. The study included three patients with uterine fibroids smaller than 3 cm, utilizing 81 selected images from MRI sequences. These images were processed using Gaussian filtering followed by three independent enhancement methods: Laplacian edge sharpening, Contrast Limited Adaptive Histogram Equalization (CLAHE) and Discrete Wavelet Transform (DWT). Three experienced radiologists independently evaluated both the original and the corresponding enhanced images using a visual rating scale ranging from 1 lowest to 10 highest, where higher scores indicated improved lesion visibility. Inter-rater agreement and reliability were assessed using the Intraclass Correlation Coefficient (ICC) and weighted Cohen’s kappa, while repeated-measures analysis was employed to account for the repetitive nature of the evaluations. The results demonstrated a generally good-to-high level of inter-rater agreement and reliability, with Intraclass Correlation Coefficient (ICC) values ​​ranging from 0.717 to 0.887. Weighted Kappa values ​​also indicated moderate-to-high agreement between pairs of raters. Repeated-measures analysis revealed statistically significant differences in ratings based on the rater and the imaging sequence, whereas the interaction between the rater and the imaging sequence was not statistically significant. These findings suggest that digital image enhancement may improve the visibility and prominence of small uterine fibroids on MRI scans. However, given that the study included only three patients and did not employ an independent diagnostic reference standard, these results are preliminary and should not be interpreted as evidence of improved diagnostic accuracy.