Radiation dose of cardiac computed tomography - what has been achieved and what needs to be done.

This review highlights the recently introduced techniques by manufacturers and various research workers to reduce radiation dose in coronary CT. It discusses in detail the development of ECG-based tube current modulation, the application of low tube voltage protocols and prospective ECG-gating. It also briefly discusses two further methods of dose reduction, namely minimisation of the x-y anatomical coverage and adaptive statistical iterative reconstruction.