Dose reduction in multislice computed tomography

Objective: Evaluation of the attenuation-based on-line modulation of tube current on multislice computed tomography (CT) to explore the potential of this dose-saving technique. Methods: Fifty-five patients with follow-up CT examinations were scanned without and with a CARE Dose (Siemens Medical Solutions, Erlangen, Germany). The applied dose, image noise, and subjective image quality were evaluated. The reduction in patient exposure was determined by obtaining the effective milliamperes per second for each reconstructed scan and the absolute dosage requirement for the whole scan. Results: The dose reduction achieved by applying the attenuation-based on-line modulation of tube current was 29.4% +/- 3.1% (P = 0.002) for all scans, 30.5% +/- 3.2% (P = 0.002) for the thorax scans, 29.7% +/- 2.9% (P = 0.002) for the abdomen scans, and 28.7% +/- 2.7% (P = 0.003) for the thorax and abdomen scans together. No significant restrictions in image quality were observed. Conclusions: Remarkable dose reduction can be obtained using the attenuation-based on-line modulation of tube current on multislice CT without compromising image quality.