Low-dose non-contrast examination of the temporal bone using volumetric 320-row computed tomography


Pirimoglu B., SADE R., SAKAT M. S., Polat G., Kantarci M.

Acta Radiologica, vol.60, no.7, pp.908-916, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 60 Issue: 7
  • Publication Date: 2019
  • Doi Number: 10.1177/0284185118802597
  • Journal Name: Acta Radiologica
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.908-916
  • Keywords: 320-row detector CT, Low dose, temporal bone
  • Kütahya Health Sciences University Affiliated: No

Abstract

Background: 320-row volume computed tomography (CT) allows CT dose to be reduced while maintaining image quality. Purpose: To evaluate image quality of low-dose non-contrast temporal bone CT using single volumetric 320-row multidetector CT technique. Material and Methods: A total of 125 patients were included in our study. Two low-dose protocols, including 135 kV tube voltage with 5 mAs tube current and 80 kV tube voltage with 5 mAs tube current, were chosen based on results of present phantom study. For evaluating subjective image quality, conspicuity of anatomic landmarks were assigned a score using a five-point scale. Objective image quality analysis was performed by analyzing regions of interest on axial soft-tissue and bone reconstructions. Effective dose was calculated from dose-length product. Results: Mean effective radiation dose for 120 kV and 75 mAs protocol (control group) was 0.29 ± 0.04 mSv; for 135 kV and 5 mAs protocol (study group A), this value was 0.02 ± 0. 003 mSv; and for 80 kV and 5 mAs protocol (study group B), this value was 0.005 ± 0. 0009 mSv. Mean effective radiation doses of study group A and B were significantly lower than the control group (P < 0.001). Study group A and control group images showed no significant difference in image quality except for some anatomic landmarks. Study group B images had lower image quality than control group images. Conclusions: Temporal bone CT with 135 kVp and 5 mAs can be performed at very low radiation exposure while maintaining high image quality.