Clinical Temporal Bone Imaging at 0.55T: Comparison of Anatomic Evaluation to 1.5/3T MRI and High-Resolution CT

Motivation: Identify whether 0.55T MRI may be superior or a clinically acceptable alternative to 1.5T/3T for temporal bone evaluation Goal(s): To compare image quality, visibility of temporal bone anatomy, and cochlear measurements at 0.55T vs. 1.5T/3T, using high-resolution CT (HRCT) as the gold standard. Approach: Retrospective assessment of 25 non-pathological ears imaged with temporal bone MRI at 0.55T and 1.5T/3T by 3 blinded radiologists. Available HRCT (n=13) were also reviewed. Results: For most readers, visibility of normal temporal bone anatomy on 3D T2w SPACE at 0.55T was clinically acceptable. Quantitative evaluation of bony anatomy was similar at 0.55T vs. 1.5/3T compared to HRCT. Impact: Clinical evaluation of the temporal bone and inner ear structures can be comparably performed on a 3D T2w SPACE sequence at 0.55T when compared to 1.5/3T, which may represent a use-case for the Free.Max 0.55T (Siemens Healthineers) scanner.