TY - JOUR
T1 - Reducing Radiation Dose for High-resolution Flat-panel CT Imaging of Superior Semicircular Canal Dehiscence
AU - El Mekabaty, Amgad
AU - Pross, Seth E.
AU - Martinez, Mesha
AU - Carey, John P.
AU - Pearl, Monica S.
N1 - Publisher Copyright:
© 2018 Lippincott Williams and Wilkins. All rights reserved.
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Objective: High-resolution flat panel computed tomography (FPCT) is useful for the evaluation of temporal bone pathologies. While radiation exposure remains a concern, efforts have been devoted to reduce dose, while maintaining image quality. We hypothesize that removing the antiscatter grid (ASG) results in decreased radiation exposure, while maintaining diagnostic image quality for the evaluation of superior semicircular canal dehiscence (SSCD). Methods: Ten patients with clinical suspicion for SSCD participated in this prospective study. Two sequential collimated 20-second FPCT acquisitions were performed (first: Grid in; second: Grid removed) in all patients. Secondary reconstructions were created by manually generating the volume of interest to include the middle ear using a voxel size of 0.1mm and 512 _ 512 matrix. Radiation dose parameters (air kerma (Ka,r) in mGy and dose area product (DAP) in mGym2) were recorded. Three reviewers analyzed images for the ability to diagnose SSCD, to identify the stapes crurae, and to determine if an ASG was present. Results: The average Ka,r and DAP for the grid-in acquisitions were 246.7 mGy (SD 47.9) and 2838.0mGym2 (SD 862.8), versus 160.2 mGy (SD 33.2) and 2026.3mGym2 (SD 644.8) for the grid-out acquisitions, respectively ( p<0.001 for both Ka,r and DAP). Radiation exposure was reduced by approximately 30% solely by removing the ASG. All reviewers correctly identified all patients with SSCD (confirmed at surgery), with mean AUC of 0.99 (k=0.90). Conclusion: Removing the antiscatter grid during FPCT imaging of the temporal bones is a simple and effective way to reduce radiation exposure while maintaining diagnostic image quality for the evaluation of SSCD.
AB - Objective: High-resolution flat panel computed tomography (FPCT) is useful for the evaluation of temporal bone pathologies. While radiation exposure remains a concern, efforts have been devoted to reduce dose, while maintaining image quality. We hypothesize that removing the antiscatter grid (ASG) results in decreased radiation exposure, while maintaining diagnostic image quality for the evaluation of superior semicircular canal dehiscence (SSCD). Methods: Ten patients with clinical suspicion for SSCD participated in this prospective study. Two sequential collimated 20-second FPCT acquisitions were performed (first: Grid in; second: Grid removed) in all patients. Secondary reconstructions were created by manually generating the volume of interest to include the middle ear using a voxel size of 0.1mm and 512 _ 512 matrix. Radiation dose parameters (air kerma (Ka,r) in mGy and dose area product (DAP) in mGym2) were recorded. Three reviewers analyzed images for the ability to diagnose SSCD, to identify the stapes crurae, and to determine if an ASG was present. Results: The average Ka,r and DAP for the grid-in acquisitions were 246.7 mGy (SD 47.9) and 2838.0mGym2 (SD 862.8), versus 160.2 mGy (SD 33.2) and 2026.3mGym2 (SD 644.8) for the grid-out acquisitions, respectively ( p<0.001 for both Ka,r and DAP). Radiation exposure was reduced by approximately 30% solely by removing the ASG. All reviewers correctly identified all patients with SSCD (confirmed at surgery), with mean AUC of 0.99 (k=0.90). Conclusion: Removing the antiscatter grid during FPCT imaging of the temporal bones is a simple and effective way to reduce radiation exposure while maintaining diagnostic image quality for the evaluation of SSCD.
KW - Flat-panel CT
KW - Radiation dose reduction
KW - Superior semicircular canal dehiscence
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U2 - 10.1097/MAO.0000000000001927
DO - 10.1097/MAO.0000000000001927
M3 - Article
C2 - 30113564
AN - SCOPUS:85072021003
SN - 1531-7129
VL - 39
SP - E683-E690
JO - Otology and Neurotology
JF - Otology and Neurotology
IS - 8
ER -