Editorial: The revival of step-and-shoot computed tomography

The advent of multidetector row spiral computed tomography (CT) is one of the most groundbreaking innovations in the field of diagnostic imaging over the past decade. Because of the high temporal and spatial resolution of recent single-source and dual-source CT scanner types, robust CT imaging of the coronary arteries has become feasible with a high diagnostic accuracy. Because the increased robustness and performance of new imaging modalities is generally accompanied by their increasing use, cardiac CT is currently performed in more and more centers worldwide.

The recent advances in the spatial and temporal resolution of spiral CT scanners, however, were paralleled by an increase in the radiation dose of cardiac CT examinations. This rise in the radiation dose has been documented from early CT studies with 4-slice technology until the introduction of 64-slice CT scanners with effective doses of up to 21 mSv. These radiation dose values were mainly the result of the low helical pitch values (ie, the slow table feet) that are required for data acquisition in the retrospective electrocardiography (ECG)–gating mode. On the basis of a flexible use of the ECG-based tube current modulation technique, a heart rate–adapted pitch, and because of the implementation of x-ray beam filters, the effective radiation dose of a retrospectively ECG-gated dual-source CT examination declined to 7–9 mSv. Additional dose-saving approaches such as the use of low kilo-voltage protocols and attenuation-based tube current modulation that are feasible in normal-weight and underweight patients should help to further reduce the radiation dose in selected patients. (…)

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Journal of Cardiovascular Computed Tomography (2008) 2, 91–92