An evaluation of organ dose modulation on a GE optima CT660‐computed tomography scanner

Organ Dose Modulation or ODM (GE Healthcare, Milwaukee, WI) was evaluated to characterize changes in [Formula: see text] , image noise, effective dose, and organ dose saving to patients. Three separate investigations were completed: a tube current modulation phantom was scanned with and without ODM, a [Formula: see text] phantom was scanned with ODM, and Monte Carlo simulations were performed. ODM was found to reduce the [Formula: see text] by approximately 20% whilst increasing the noise by approximately 14%. This was reflected in the dose distribution, where the anterior peripheral dose was reduced by approximately 40% whilst the identical posterior dose remained largely unaffected. Enabling ODM for the entire scan would reduce the effective dose by approximately 24%; however, this saving reduces to 5% if the images are matched for [Formula: see text]. These savings mostly originated from reductions in dose to the stomach, breasts, colon, bladder, and liver. ODM has the effect of a global reduction in [Formula: see text] with an associated increase in image noise. The benefit of ODM was found to be reduced when the dose‐saving contribution from the reduced [Formula: see text] was removed. Given that there is a higher contribution to effective dose throughout the body from the anterior projections, consideration should be given to applying ODM throughout. PACS number(s): 87.10.Rt, 87.53.Bn, 87.57.C‐, 87.57.Q‐