Feasibility study of the application of Magnetic Resonance Elastography (MRE) to diagnose adenomyosis.

Abstract

Objective: Magnetic Resonance Elastography (MRE), a novel imaging technique that allows in vivo measurement of tissue mechanical properties, was used to test the prediction that the stiffness of the uterus may be increased due to fibrotic changes in patients with adenomyosis.

Design: A feasibility study in which a 3D MRE imaging protocol was developed to measure the stiffness of the tissues of the uterus.

Subjects: Four patients with suspected adenomyosis and heavy menstrual bleeding (HMB) diagnosed via transvaginal ultrasound and clinical history and one healthy control were recruited. Two patients underwent hysterectomy and histological analysis of the tissue samples was performed.

Main outcome measures: The stiffness of the whole uterus was obtained by Region of Intertest (ROI) analysis of the 3D MRE images for the four patients and one healthy control. In addition for the two patients who underwent hysterectomy the uterine tissue samples were assessed to determine (i) histological presence of adenomyosis via H&E staining, (ii) cellular/molecular measures of tissue stiffness (collagen [picrosirius red], α-smooth muscle actin, e-cadherin) and (iii) if a relationship exists between in vivo assessment of the uterus via 3D MRE and in vitro uterine tissue histology.

Results: 3D MRE was successfully used to acquire elastograms for four patients with adenomyosis (diffuse n=3, focal n=1) and one healthy volunteer. Calculated global uterine stiffness was higher in women with adenomyosis (2.93 kPa; range 2.34 - 3.39 kPa) compared to the healthy volunteer (2.04 kPa). Regions of high stiffness on the 3D elastograms reflected adenomyotic changes visualised via conventional MRI, and correlated with histological and immunohistochemical markers of tissue stiffness.

Conclusion: 3D MRE has the potential to provide non-invasive characterisation of changes in the mechanical properties of uterine tissue that is not possible using conventional MRI, or transvaginal ultrasound. Further studies are needed to confirm the efficacy of the 3D MRE protocol for diagnosing adenomyosis.