Comparison of Supine and Prone Positions for Dental MRI with a Microscopy Coil: Image Quality and Patient Burden in Healthy Volunteers

Objectives This study aimed to evaluate the clinical feasibility of dental magnetic resonance imaging (MRI) using a microscopy coil by comparing imaging positions in healthy volunteers. Methods Twenty-six healthy volunteers underwent dental MRI in supine and prone positions using a 47 mm microscopy coil on a 3.0T system. T1-weighted (T1W), T2-weighted (T2W), and proton density-weighted (PDW) sequences were acquired. Participant-reported burden was assessed using a 10-point scale. Image quality was evaluated using a 4-point scale for sharpness, artifact, perceived signal-to-noise ratio (SNR), and overall quality. SNR and contrast-to-noise ratio (CNR) were calculated from 1 mm ² regions of interest in dental pulp, inferior alveolar neurovascular bundle, and bone marrow. Statistical analyses included the Wilcoxon signed-rank test, Fisher's exact test, and paired t-test. Results Participant-reported burden was lower in the supine position (1.7 ± 1.1) than in the prone (4.7 ± 2.1). Visual assessments demonstrated superior image quality in supine across all sequences. The proportion of non-diagnostic images was higher in the prone position: T1W (50% vs. 19%), T2W (46% vs. 4%), and PDW (38% vs. 8%). SNR and CNR showed no differences between positions. Image quality degraded with prolonged examination time regardless of position. Conclusions The supine position demonstrated lower subjective burden, better visual image quality, and a lower rate of non-diagnostic images compared with the prone position. Image quality was optimal when MRI was performed early in the examination sequence. Therefore, the supine position is more appropriate for dental MRI using a microscopy coil.