High-Resolution CT of the Temporal Bone for Diagnosing Small Ear Bone Breaks

Introduction to HRCT

High-resolution computed tomography (HRCT) of the temporal bone is the imaging modality of choice for diagnosing small ear bone (ossicular) breaks or fractures, as recommended by the American College of Radiology 1, 2

The American College of Radiology recommends non-contrast high-resolution CT for evaluation of ossicular structures, as intravenous contrast is not beneficial due to the density of the surrounding temporal bone 4
Bone algorithm reconstructions are recommended to maximize visualization of ossicular structures, according to the American College of Radiology 5
Reconstructions along multiple planes (axial, coronal, and sometimes oblique) are necessary to fully assess the ossicular chain, as suggested by the American College of Radiology 4

HRCT is particularly valuable in post-traumatic hearing loss, where it can demonstrate fractures extending across the otic capsule or involving the ossicular chain, as noted by the American College of Radiology 4
In conductive hearing loss, HRCT helps identify ossicular erosion, fusion, or displacement that may result from trauma, according to the American College of Radiology 3

While HRCT excels at bone imaging, it is less sensitive for detecting soft tissue abnormalities that may accompany ossicular injuries, as reported by the American College of Radiology 4

Standard head CT lacks the necessary resolution to adequately visualize the small ossicular structures and should not be used for this purpose, as stated by the American College of Radiology 6, 7
CT angiography (CTA) of the head is not indicated for evaluation of ossicular chain injuries, according to the American College of Radiology 2, 4
MRI alone is insufficient for evaluating ossicular fractures due to its limited ability to delineate bony details, as noted by the American College of Radiology 4