Purpose: We aimed to determine whether the presence of the distal oblique bundle (DOB) can be evaluated in magnetic resonance imaging (MRI) examinations. Methods: We retrospectively reviewed 468 wrist and forearm MRIs taken in patients without acute fractures, infections, or tumors, and selected 80 MRIs that provided adequate coverage of the distal interosseous membrane (DIOM). We measured the thickness of the DIOM in the T2- weighted transverse plane. We used a picture archiving and communicating system and a model-based clustering method to determine whether some individuals have thicker DIOMs that can be considered as the DOB. Results: The thickness of the DIOM demonstrated a bimodal distribution, indicating the presence of patients with a thick DIOM (DOB). The model-based clustering method indicated that the optimal cutoff point was 1.0 mm. Twenty-six individuals (32.5%) had thick DIOMs with a mean thickness of 1.4 mm (SD, 0.2 mm), whereas 54 individuals (67.5%) had thin DIOMs with a mean thickness of 0.6 mm (SD, 0.2 mm). Conclusions: This study demonstrates that MRI can identify the presence of the DOB. The incidence and thickness of the DOB in this study support the findings of previous cadaveric studies on its morphology.
