High-resolution CT of the temporal bone: a modified baseline.

Abstract

High-resolution computed tomography (CT) of the temporal bone, particularly axial scanning on a baseline parallel to the orbitomeatal line, produces radiation exposure to the patient's lenses. The authors evaluated the radiation dose to the lens and the visualization of temporal bone structures with use of scanning along the orbitomeatal line and on a line parallel to the hard palate. Evaluation of visualization was performed by five radiologists, with high-resolution CT scans of 45 healthy patients, and the chi 2 test was performed for comparison. The change of the baseline from the orbitomeatal line to a line parallel to the hard palate decreased the radiation dose to the lens from 12.7 cGy to 0.274 cGy and improved visualization of the stapes superstructure and the tympanic portion of the facial nerve canal, although visualization of the incus body, incudostapedial joint, lateral semicircular canal, and oval window was of equal quality. Therefore, the authors recommend a new baseline parallel to the hard palate for use at high-resolution CT of the temporal bone.

Can MRI Replace CT in Evaluating Semicircular Canal Dehiscence?

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Radiological Dehiscence of the Mastoid Portion of the Facial Nerve after Posterior Tympanotomy: Does It Lead to Increased Risk of Nerve Injury?

“…This was not possible as we used HRCT routinely only between 2004 and 2009. HRCT was used to visualise the number of intracochlear electrodes to facilitate mapping by the audiology staff, but was abandoned due to concerns of excessive radiation [20] . Despite this, we consider the cases retrieved to be representative of the general CI population, with a reasonable case mix of adults and children, so we believe that our study gives a valid snapshot of the surgical anatomy.…”

Temporal bone anatomy: correlation of multiplanar reconstruction sections and three-dimensional computed tomography images

“…Although direct sagittal scanning was reported in 1998, 4 imaging facilities were limited as a special head holder for temporomandibular joint imaging was required. In 1992, a modifi ed baseline parallel to the hard plate that had smaller scan coverage and lower radiation dose to the lens was proposed, 5 and its use became widespread. Progressing into the MSCT scanner era, acquisition of high-resolution isotropic volume data 1 and an advanced MPR technique have made it possible to use not only axial, coronal, and sagittal sections but also an oblique section for depicting objects.…”