Skip Navigation LinksHome > January/February 2011 - Volume 35 - Issue 1 > Extra Z-Axis Coverage at CT Imaging Resulting in Excess Radi...
Journal of Computer Assisted Tomography:
doi: 10.1097/RCT.0b013e3181f5a652
Original Articles

Extra Z-Axis Coverage at CT Imaging Resulting in Excess Radiation Dose: Frequency, Degree, and Contributory Factors

Liao, Eric A. MD; Quint, Leslie E. MD; Goodsitt, Mitchell M. PhD; Francis, Isaac R. MD; Khalatbari, Shokoufeh MS; Myles, James D. PhD

Collapse Box

Abstract

Objective: To assess the degree of extra scanning beyond the prescribed anatomic boundaries for thoracic and body computed tomographic (CT) scans and to identify associated factors.

Methods: For 442 consecutive chest, abdomen, and/or pelvis CT examinations, the length of extra scanning beyond the prescribed anatomic boundaries was determined. Examinations were grouped according to the locations/types of the prescribed boundaries and compared with regard to length of extra scanning.

Results: Of 442 CT examinations, 438 (99%) included extraneous imaging, showing a mean excess scanning length of 43.2 mm per examination (range, 0-180 mm). Significantly more extraneous imaging was performed when soft tissue or vascular structures defined anatomic boundaries compared to when osseous (P < 0.001) or air/soft tissue interfaces (P < 0.0001) defined the boundaries. The average percent of total scan dose attributable to extra imaging was 8.64% to 10.38%.

Conclusions: Computed tomographic scanning beyond the prescribed anatomic boundaries occurs commonly, resulting in moderate extra radiation dose.

Copyright © 2011 Wolters Kluwer Health, Inc. All rights reserved.

  

Login

Article Tools

Share

Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.