Monique Brink MD, Presenter: Nothing to Disclose

Frank de Lange PhD, Abstract Co-Author: Nothing to Disclose

Luuk J. Oostveen Dipl Phys, Abstract Co-Author: Nothing to Disclose

Helena Maria Dekker MD, Abstract Co-Author: Nothing to Disclose

Digna Rosemarijn Kool MD, Abstract Co-Author: Nothing to Disclose

Johan G. Blickman MD, PhD, Abstract Co-Author: Nothing to Disclose

Cornelis van Kuijk MD, PhD, Abstract Co-Author: Nothing to Disclose

Jaap Deunk MD, Abstract Co-Author: Nothing to Disclose

Arie van Vugt PhD, Abstract Co-Author: Nothing to Disclose

Richard L. Kamman PhD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To evaluate the effect of arm position on effective radiation dose and image quality in an automated tube current modulated (TCM) multi-detector row computed tomography (MDCT) protocol of thorax and abdomen in trauma patients.

A total of 177 trauma patients were scanned following a TCM (Care Dose 4D) 16 row thoraco-abdominal CT protocol. Scan parameters were 120 kV, 16 x 1.5 mm collimation and a reference value of effective tube current time product of 200 mAs. Patients were scanned either with both arms raised above the shoulder region (standard-position-group), with one arm down (1-arm-group) or with two arms down (2-arms-group), depending on to what extent patients were able to raise their arms. Individual effective radiation dose was calculated directly from the effective tube current time product per exposed slice. For this purpose, slice-location dependent conversion factors were derived using a CT dosimetry calculator (ImPACT, London, UK). The effect of arm position on effective dose was quantified after correction for patient volume and attenuation. Phantom studies were performed for verification purposes. In addition, both objective and subjective image quality were assessed.

Median (volume and attenuation corrected) effective dose in the standard-position-group (132 patients) was 18.6 mSv. In the 1-arm-group (27 patients), this was 18% (95% CI 11-25%) higher and in the 2-arms-group (18 patients) this was 45% (95% CI 34-57%) higher. In both arm-groups image quality decreased, but remained within acceptable diagnostic limits.

Omitting arm raising results in a substantially higher effective radiation dose and in an acceptable, but lower image quality.

Serious effort should be made to position the upper extremities above the shoulder in scanning trauma patients as this will result in higher image quality and a lower effective radiation dose.

Brink, M, de Lange, F, Oostveen, L, Dekker, H, Kool, D, Blickman, J, van Kuijk, C, Deunk, J, van Vugt, A, Kamman, R, et al, , et al, , Arm Raising in Tube Current Modulated Trauma CT of the Trunk: Higher Image Quality, Lower Effective Radiation Dose.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5004191.html