Christian C. Hohl MD, Presenter: Nothing to Disclose

Jan Boese, Abstract Co-Author: Employee, Siemens AG

Norbert Strobel, Abstract Co-Author: Employee, Siemens AG, Forchheim, Germany

Rosemarie Banckwitz, Abstract Co-Author: Employee, Siemens AG

Rolf W. Günther, Abstract Co-Author: Nothing to Disclose

Dagmar Honnef MD, Abstract Co-Author: Nothing to Disclose

Measurement of organ and effective doses during angiographic CT (ACT) examinations of head and heart in a pedeatric anthropomorphic phantom with thermoluminiscent dosimeters (TLD).

ACT is a cross-sectional imaging modality for soft-tissue structures using C-arm-fluoroscopy with flat-panel detectors (FPD). ACT is utilized in children to guide interventional procedures in congenital heart defects or cerebral vascular malformations. To measure the organ and effective doses during head- and brain-examinations, a pediatric anthropomorphic phantom (ATOM, CIRS, Norfolk, VA, USA), representing a five year-old boy, was equipped with 132 TLD in 44 different positions representing relevant organs regarding ICRP-recommendations. The examinations were performed with an angiographic C-arm-system (Axiom Artis Dyna-CT, Siemens, Forchheim, Germany) with a 20 x 20cm FPD. Two different standard protocols recommended by the vendor were used to examine the head (70kV, 0.36µGy/frame, 126 frames) and the heart (70kV, 0.54µGy/frame, 126 frames). The TLD wear read out immediately after each examination. Organ and effective doses were calculated regarding ICRP-recommendations and compared to known dose values of matching standard MSCT-scans of the head and the heart.

The measured effective doses amounted to 0.11 mSv for the head and 0.46 mSv for the heart. The effective doses of the ACT-examinations were noticeably lower than the comparable MSCT-doses (1.8 mSv head, 9 mSv heart).

ACT-examinations have even lower doses than comparable MSCT-examinations. Further dose reduction ACT of the heart can be expected using an ecg-triggered protocol.

ACT is a promising imaging technique for interventional procedures in children with an effective dose comparable to MSCT examinations.

Hohl, C, Boese, J, Strobel, N, Banckwitz, R, Günther, R, Honnef, D, Angiographic CT: Measurement of Radiation Dose in Children.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6022181.html