Coronary Enhancement for Prospective ECG-Gated Single R-R Axial 320-MDCT Angiography: Comparison of 60- and 80-mL Iopamidol 370 Injection

Abstract

An injection protocol based on 60 mL of iopamidol (370 mg I/mL) for prospectively ECG-gated wide-area detector single-heartbeat coronary CT angiography (CTA) has less coronary enhancement than a protocol based on 80 mL. However, using 60 mL, more than 96% of coronary segments had sufficient enhancement (i.e., > 300 HU), supporting the general use of 60-mL protocols for clinical wide-area detector coronary CTA.

Contrast Media Administration in Coronary Computed Tomography Angiography – A Systematic Review

“…In the vast majority of the included publications, a tube voltage of 120 kV was used. Some of the included papers either did not mention tube voltage or mention lower or various kV settings [48,59,63,70,73,74]. As different vendors and scanners were used, scan-related parameters such as collimation, slice reconstruction and kernel were not comparable and occasionally missing.…”

“…However, only four CM injection protocols make use of CM concentrations below 320 mg/ml [7,15,19,73]. The variation in injection rate was higher than for CM concentrations, varying between 2.5 ml/s [19] and 6 ml/s [55,63,70]. The majority of the included papers keep injection rate relatively constant when comparing different groups.…”

“…IDR ranged between 0.99gI/s and 2.22gI/s and proved to be very heterogeneous. A limited number of injection protocols stated usage of an IDR above 1.9gI/s [54,55,63,70]. All included publications that stated a flow rate below 4 ml/s also reported an IDR < 1.4gI/s [7,46,47,61,64,75].…”

“…When the IDR between subgroups was kept identical, numerous publications did not find statistically significant differences in coronary attenuation [7, 15, 19, 44 -46, 49, 51, 60, 70, 71]. In both groups (variable and identical IDR), other injection-related parameters varied substantially, making it difficult to determine the true influence of IDR on coronary attenuation [47,50,53,55,57,63,74]. Three studies report significant differences between CM concentrations in favor of higher CM concentrations [15,16,62].…”

Important Advances in Technology and Unique Applications to Cardiovascular Computed Tomography

“…In addition, wider coverage also translates into shorter image acquisition times, which in sequence means that a smaller amount of contrast medium is required to obtain optimal scans while still preserving coronary artery enhancement. 3 The major drawbacks in wide-detector technology include over-ranging and disadvantages associated with cone beam reconstruction. Over-ranging refers to the extra rotation of a gantry at the beginning and end of the actual scan volume, which is required to overcome a cone beam artifact at either end of the scanning volume.…”