Computed tomography imaging can assess not just the coronary arteries but also the structure, function, perfusion and viability of the myocardium. (Williams et al., 2011) However, radiation dose remains a major health care concern due to the increased lifetime risk of cancer (Einstein, Henzlova, & Rajagopalan, 2007). Radiation dose reduction in computed tomography coronary angiography can be achieved through protocol optimisation, patient tailored imaging and improvements in software and hardware. Adaptive Iterative Dose Reduction 3D (AIDR3D, Toshiba Medical Systems, Japan) is an iterative reconstruction algorithm...

Participants underwent rest computed tomography coronary angiography and adenosine stress computed tomography myocardial perfusion imaging using a 320-multidetector scanner (Aquilion ONE, Medical Systems, Japan). Contrast volume was selected based on body mass index. For Group 1 tube current was selected based on body mass index, multi-segment acquisition was used, 120kV was used for all patients and images were reconstructed using a filtered back projection reconstruction algorithm (QDS+). For Group 2 tube current was automatically adjusted based on scout image attenuation (SureExposure, Toshiba Medical systems), tube...

For the 28 patients in Group 1 and 18 patients in Group 2 there was no difference in gender, body mass index or heart rate at rest or stress (Table 1). There was no difference in z-axis collimation during rest or stress between groups. (Table 2). There was a significant reduction in tube current and tube voltage in Group 2. (Table 2) There was a significant reduction in the DLP of rest imaging (Figure 1), stress imaging (Figure 2) and the total protocol radiation dose...

Iterative reconstruction and patient tailored imaging led to a 60% reduction in CTP radiation dose, while maintaining image quality. Thus a comprehensive cardiac computed tomography scan including information on anatomy, function, perfusion and viability can be performed at an average radiation dose of 5.4mSv (k 0.014).

Alkadhi, H., Stolzmann, P., Scheffel, H., Desbiolles, L., Baumüller, S., Plass, A., Genoni, M., et al. (2008). Radiation dose of cardiac dual-source CT: the effect of tailoring the protocol to patient-specific parameters. European Journal of Radiology, 68(3), 385–91. Einstein, A. J., Henzlova, M. J., & Rajagopalan, S. (2007). Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA, 298(3), 317–23. Gagarina, N. V, Irwan, R., Gordina, G., Fominykh, E., & Sijens, P. E. (2011). Image quality in reduced-dose coronary CT...