Radiation Dose to the Lens Using Different Temporal Bone CT Scanning Protocols

Abstract

BACKGROUND AND PURPOSE:Temporal bone CT is performed frequently in clinical practice. At the same time, the eye lens are exposed to ionizing radiation without any useful diagnostic information delivered. Our aim was to investigate the radiation dose to the lens of the eye by using temporal bone CT scanning with different protocols.

Radiation Dose Reduction in Temporal Bone CT with Iterative Reconstruction Technique

“…Axial and coronal images were reformatted according to the standard clinical practice. 6 Image quality assessments were performed on a CT postprocessing workstation (Extended Brilliance Workspace; Philips Healthcare). Circular regions of interest of 50 mm 2 were placed in the brain stem region and air space lateral to the external auditory canal (Fig 2).…”

Multidetector computed tomography (MDCT) images with soft tissue and bone algorithm reconstruction in head and facial trauma

“…1 Using the conventional brain CT protocol with the glabellomeatal or orbitomeatal line as the baseline, the patients' eyes are positioned within the scanning field. 2 During conventional facial bone CT scans, the lens is also irradiated. This is important, because the lens of the eye is one of the most radiosensitive organs, especially in children.…”

A preliminary investigation of four-dimensional ultrasound for evaluation of middle ear ossicles: An in vitro study

“…Unavoidable radiation exposure to the lens of the eye, orbit, brain and bone marrow during axial temporal bone CT scanning is concerning [7,8]. While the dose to the lens is comparatively small (50 mSv) [7], it is within the lower 90% confidence limits of thresholds for development of cortical cataracts and posterior subcapsular opacities in atomicbomb survivors [8,9].…”

“…Unavoidable radiation exposure to the lens of the eye, orbit, brain and bone marrow during axial temporal bone CT scanning is concerning [7,8]. While the dose to the lens is comparatively small (50 mSv) [7], it is within the lower 90% confidence limits of thresholds for development of cortical cataracts and posterior subcapsular opacities in atomicbomb survivors [8,9]. These risks may be greater than stated because CT parameters may not be adjusted for children [10], a child's body provides less shielding of critical organs [5], children have a longer life over which they can express damage from radiation, and the largest increase in CT use is for pediatric diagnoses [5,10].…”