Feasibility of low-dose coronary CT angiography: first experience with prospective ECG-gating

Abstract

This first experience documents the feasibility of prospective ECG-gating for CTCA with diagnostic image quality at a low radiation dose (1.1-3.0 mSv), favouring HR <63 b.p.m.

Validation of a new contrast material protocol adapted to body surface area for optimized low-dose CT coronary angiography with prospective ECG-triggering

“…Computed tomography coronary angiography (CTCA) is a lately introduced non-invasive cardiac imaging method, which has been shown to reliably detect significant CAD (greater than 50% luminal narrowing) [1]. Prospective ECGtriggering has allowed to substantially reduce radiation dose of CTCA from about 15 to 20 mSv down to 1 to 3 mSv at maintained image quality [2] and accuracy [3,4] so that the clinical acceptance of CTCA is growing. Coronary vessel attenuation may affect the accuracy of CTCA [5][6][7] as for an accurate detection of coronary plaque an appropriate amount of contrast material (CM) is needed.…”

“…Previous CTCA protocols [2,[16][17][18] did not adapt to patients individual body mass or cardiac output. Consequently, vessel attenuation in CTCA has been shown to vary strongly [6][7][8][9], depending on BMI and to affect the optimal detection of coronary plaque.…”

Determinants of vessel contrast in BMI-adapted low dose CT coronary angiography with prospective ECG-triggering

“…The use of this CTCA protocol allows to reduce radiation dose from about 15mSv in spiral scanning with ECG-modulated tube current down to about 2 mSv [5] by administering radiation dose only at one predefined end-diastolic time point instead of during a whole phase of the cardiac cycle [6].…”

Focus on radiation exposure from cardiovascular imaging with computed tomography

“…However, because X-ray exposure occurs throughout the cardiac cycle (despite reduced tube current outside a pre-specified, typically diastolic window = 'tube current modulation') these protocols are associated with higher radiation exposure. More recently, sequential acquisition has become possible for cardiovascular CT, where data is acquired only in the pre-specified window of the cardiac cycle ('axial imaging with prospective triggering') [11]. Because the X-ray tube is turned off outside the pre-specified window, radiation exposure is significantly reduced.…”

“…In particular, the absolute dose of 1.9 mSv for coronary CTA with prospective scanning at 100 kV appears achievable [11]. As pointed out by Achenbach in an accompanying editorial the goals of high diagnostic image quality and low radiation dose need to be balanced in individual patients, ''even if it requires a little extra effort''.…”