Alice Boyd Smith MD, Abstract Co-Author: Nothing to Disclose

William P. Dillon MD, Abstract Co-Author: Contract, CoAxia, Inc Contract, sanofi-aventis Group Adjudicator, Actelion Ltd Research grant, General Electric Company

Benison Lau, Abstract Co-Author: Nothing to Disclose

Robert G. Gould ScD, Presenter: Medical Advisory Committee, Agfa-Gevaert Group Medical Advisory Board, General Electric Company Research grant, Agfa-Gevaert Group

Francis R. Verdun PhD, Abstract Co-Author: Nothing to Disclose

Max Wintermark MD, Abstract Co-Author: Consultant, PAION AG

Edward Lopez, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To quantify the impact of systematic use of tube current modulation for neuroradiology CT protocols in terms of patient dose reduction and image quality.

As part of a retrospective study, approved by our institutional review board and in compliance with Health Insurance Portability and Accountability Act (HIPAA), we evaluated the impact of dose modulation on 4 types of neuroradiological CT studies: brain noncontrast CT (NCT) in adult patients, brain NCT in pediatric patients, adult cervical spine CT, and adult cervical and intracranial CT-angiogram (CTA). For each type of CT study, three series of 100 consecutive studies were reviewed: (1) 100 studies without dose-modulation; (2) 100 studies with Z-axis dose-modulation; (3) 100 studies with XYZ-axis dose-modulation. For each examination, the weighted computed dose tomographic index (CTDIvol) and dose length product (DLP) were recorded, and noise was measured. Each examination was reviewed by a neuroradiologist blinded to the dose modulation mode for image quality. Continuous variables (CTDIvol, DLP, noise) were compared using T-tests, and categorical variables (image quality) using Chi2 tests.

For adult brain NCT, CTDIvol and DLP were reduced by 60.0% and 60.3%, respectively, using Z-axis dose-modulation; and by 50.4% and 22.4%, respectively, using XYZ-axis dose-modulation. Significant dose reductions were also observed for pediatric brain NCT, cervical spine CT and CTAs. Image quality and noise were unaffected by use of dose modulation.

Dose-modulation techniques should be systematically used for neuroradiology CT examinations, because they afford significant dose reduction, while image quality is maintained.

Utilization of dose modulation techniques results in significant reduction in radiation dose to patients for studies typically utilized in a neuroradiology department without loss of image quality.

Smith, A, Dillon, W, Lau, B, Gould, R, Verdun, F, Wintermark, M, Lopez, E, et al, , et al, , Successful Implementation of a Radiation Dose Reduction Strategy for CT Protocols in a Neuroradiology Section.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5002212.html