Relationship between apparent diffusion coefficient value of the bone marrow and cortical width of the mandible in the healthy patients

Objectives: Diffusion-weighted imaging (DWI) is a technique reflecting motion of water proton within the tissue. Studies have investigated the apparent diffusion coefficient (ADC) of bone marrow in musculoskeletal lesions. This study assessed the correlation between the ADC of bone marrow in the mandible and the mandibular cortical width (MCW) in the healthy patients. Methods: This research was a retrospective cohort study. The patient underwent echo planar (EPI)-DWI and panoramic X-ray at the Nihon University School of Dentistry between April 2020 and October 2020. The predictor variable was mean MCW. The primary outcome variable was the mean ADC of mandibular bone marrow. The other variable was age. Data were analyzed using a Mann-Whitney U test, Spearman's correlation coefficient. Statistical significance was set at p < 0.05. Results: We analyzed the records of 18 men (mean age, 44.94, age range 20–73 years) and 40 women (mean age, 47.98, age range 21–78 years). There was not significant difference between sex and mean ADC value, mean MCW (p = 0.853 and p= 0.43, respectively). There was a significant positive correlation between MCW and the ADC of the mandibular bone marrow (r = .493, p < 0.001). Conclusions: This suggests that in addition to evaluating the MCW, which is currently used for bone quality evaluation, measuring the ADC of bone marrow in the mandible could contribute toward the examination of bone quality and diseases.