Quantitative and qualitative MRI assessment in medication-related osteonecrosis of the jaw: a retrospective analysis.

OBJECTIVE: Medication-related osteonecrosis of the jaw (MRONJ) is difficult to delineate clinically because marrow involvement may extend beyond exposed bone. This retrospective cohort study explored MRI signal characteristics in clinically exposed and nonexposed marrow, combining qualitative signal assessment with quantitative contrast-to-noise ratio (CNR) measurements on T1-weighted (T1WI) and short tau inversion recovery (STIR) images. STUDY DESIGN: Patients with confirmed MRONJ and evaluable pretreatment T1WI/STIR scans (2020-2024) were included. Intra-patient regions of interest (ROI) were placed in exposed marrow, nonexposed marrow within the same jaw, contralateral normal marrow (reference), and adjacent air (noise), and CNRs were calculated. RESULTS: Twenty-eight patients (mean age 65.6 ± 12.9 years; 60.7% female) were analyzed. In this exploratory analysis, CNRs did not differ significantly between exposed and nonexposed marrow on T1WI (median -37.85 vs -25.72; P = .066) or STIR (median 12.12 vs -0.49; P = .115), and equivalence could not be statistically confirmed. CNRs were not associated with MRONJ stage, localization, sequestrum formation, or actinomyces status (all P > .05). Quantitative CNRs correlated with qualitative signal patterns (P < .05). CONCLUSIONS: These exploratory findings raise the possibility that clinically nonexposed marrow may harbor subclinical involvement, suggesting that MRI warrants further investigation as a complementary modality for assessing disease extent in surgical planning.