Pragya Ahuja Dang MBBS, Presenter: Nothing to Disclose

Mannudeep Karanvir Singh Kalra MD, Abstract Co-Author: Research grant, General Electric Company

Chris L. Sistrom MD, Abstract Co-Author: Technical Consultant, Nuance Communications, Inc Technical Consultant, Commissure, Inc Medical Advisory Board, Nuance Communications, Inc

Thomas Schultz, Abstract Co-Author: Nothing to Disclose

Markus Stout, Abstract Co-Author: Nothing to Disclose

Keith J. Dreyer DO, PhD, Abstract Co-Author: Employee, Perceptics, LLC Medical Advisor, Perceptics, LLC Medical Advisor, Agfa-Gevaert Group Medical Advisor, FUJIFILM Holdings Corporation Medical Advisor, General Electric Company Medical Advisor, McKesson Corporation Medical Advisor, AuntMinnie.com Medical Advisor, AMICAS, Inc Medical Advisor, Dynamic Imaging, LLC Medical Advisor, Ascom Holding AG Medical Advisor, Bracco Group Medical Advisor, Merge Healthcare Medical Advisor, Emageon, Inc Medical Advisor, RCG HealthCare Consulting Medical Advisor, Valley Radiology Medical Associates, Inc Medical Advisor, The Elizabeth Wende Breast Clinic Medical Advisor, ISCI Medical Advisor, Siemens AG Medical Advisor, Barco nv Medical Advisor, Hue AS Medical Advisor, Planar Systems, Inc Medical Advisor, Vital Images, Inc Medical Advisor, Commissure, Inc Medical Advisor, TeraRecon, Inc Medical Advisor, Mercury Computer Systems, Inc Medical Advisor, IBM Corporation Medical Advisor, Hewlett-Packard Company Medical Advisor, EMC Corp Medical Advisor, Phase Forward Incorporated Medical Advisor, Winchester Systems, Inc Medical Advisor, Dell Inc Medical Advisor, Eastman Kodak Company Medical Advisor, Amirsys, Inc Medical Advisor, Reed Elsevier Committee member, Diagnostic Imaging Committee member, AuntMinnie.com Committee member, Imaging Economics Author, Springer Science+Business Media Deutschland GmbH Shareholder, Microsoft Corporation Shareholder, Intel Corporation Shareholder, IBM Corporation Shareholder, Hewlett-Packard Company Shareholder, Dell Inc Shareholder, General Electric Company Shareholder, Siemens AG Shareholder, Google Inc

Shyla S Saini, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Concerns have been expressed about increasing radiation exposure from CT scans. The purpose of our study was to estimate per scan and per patient radiation doses delivered by CT scanning in a single tertiary care institution over a 10-year period.

Information from our institution’s RIS and PACS was used to create a comprehensive data warehouse. We identified all CT exams (n=634,694) performed in 198,783 patients (age range=0-104 years, M:F=102,409:96,374) from 1996-2005. For each patient, we extracted information about their age, gender, body region(s) examined and date of the study. A sample of 45 cases in each of 8 age group by body region strata (children/adults and abdomen/chest/head/neck) was isolated. For each of these exams, scan parameters (kVp, mA, rotation time, pitch, scanner type, vendor, body region, and scan length) were recorded from DICOM headers. We used Monte Carlo simulation software (Impact Dose, UK) to estimate effective doses which were normalized for pediatric age groups and created a 2x4 table of mean effective doses. These were applied back to all exams linked by age group and body area to form an analytic data set for determining effective doses for different ages and body regions scanned over the 10 years.

Overall, the cumulative effective dose per patient was 7.4±19.4 mSv for 0-18 years and 36.2±57.2 mSv for >18 years (p<0.0001). In adults, abdomen contributed to highest annual cumulative individual doses (25.4 mSv) followed by chest (21.8 mSv). In children, chest CT contributed to the highest cumulative (12.7 mSv) individual doses per year followed by abdomen (5.3 mSv). Over 10 years, effective dose per patient per year decreased from 4.16 mSv to 4.11 mSv in children (p<0.001) and increased from 13.5 mSv to 18.7 mSv in adults (p<0.0001) although the number of CT exams per patient increased in both children and adults.

Although number of CT exams performed annually has increased in all age groups, there is marked increase in dose noted for adults (3.61%) as compared to a slight decrease in the annual effective individual doses in children (0.01%). Abdomen and chest exams contribute most to the individual radiation doses attributable to CT scanning in all ages.

Audit of 10 year CT radiation dose shows an average increase of 3.7% in annual dose with an overall average individual cumulative dose of 35.4±58.4 mSv.

Dang, P, Kalra, M, Sistrom, C, Schultz, T, Stout, M, Dreyer, K, Saini, S, et al, , CT-associated Radiation Dose Over a 10-year Period in a Single Tertiary Healthcare Center.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6010511.html