According to a new study, cone beam CT, also known as CBCT, provides better results, at half the radiation dose, when used to diagnose superior semicircular canal dehiscence than multi-detector CT. Superior semicircular canal dehiscence is a condition characterized by dizziness and loss of hearing. This condition is sometimes known as third window, where a small hole in the bony wall of the inner ear bone results in the symptoms.
The study took place in Bruges, Belgium. It involved 21 patients who underwent both CBCT and multi-detector CT scans on their right and left temporal bones. Two radiologists read the images generated using each technique and a score was given based on image quality and pathological findings.
David Volders, MD, one of the authors of the study, spoke about the findings. He said the study indicated that CBCT "corrected a false positive diagnosis for superior semicircular canal dehiscence in 11 out of 16 cases which were positive on multi-detector CT (68.8%),"
He continued saying that multi-detector CT showed a dehiscence of the superior semicircular canal when that finding actually did not exist. Meanwhile, CBCT had marked higher score than multi-detector CT in regards to visualizing the anatomy of normal temporal bone.
Dr. Volders added "In our facility, all patients who undergo temporal bone imaging to diagnose fractures, congenital middle ear deformities, chronic ear infections and conductive hearing loss are now scanned with cone beam CT,"
He concluded "The significantly better image quality and the very low radiation dose has made cone beam CT our main choice for temporal bone imaging. Radiologists should closely follow the cone beam CT evolutions and consider a cone beam CT in their practice as new generation high end cone beam CT is more and more claiming its place in diagnostic imaging of the temporal bone."