Optimization of Coronary Attenuation in Coronary Computed Tomography Angiography Using Diluted Contrast Material

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

“…The total injected CM volume ranged between 30 ml and 140 ml. Within the period of inclusion, a gradual decrease in total injected CM volume is noted, as earlier publications make mention of a total injected CM volume of 140 ml [15,44,45], whereas more recent publications reported CM injection protocols with total injected CM volumes below 40 ml [69,70,74,75]. Subsequently, the TID has substantially lowered from anywhere between 44 -56 g [15,44,45] to less than 15 g (range: 11.1 -56.0 g) [7,47,60 …”

“…The majority of the included papers keep injection rate relatively constant when comparing different groups. Only a few studies mention substantial differences in flow rates between groups [19,55,61,75]. 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]. However, lower CM concentrations were not always associated with lower IDR levels, as some publications state IDR levels ≥ 1.4gI/s with usage of lower (e. g. 320 mg/ml) CM concentrations, indicating that the CM injection rate might have a greater influence on the calculated IDR [45,48,59].…”

“…Conflicting results were reported with regard to the influence of IDR on coronary attenuation. When the IDR differed between subgroups, various publications found significant differences in the attenuation of the coronary arteries in favor of a higher IDR [7,15,16,55,61,62,68,69,75]. 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].…”

Optimizing Contrast Medium Injection for Coronary CT Angiography Using Myocardial CT Perfusion Data

“…The relationship between the predicted and actual coronary enhancement was better when diluted contrast medium was used than with undiluted contrast medium [10]. Coronary CTA with the amount of contrast medium calculated from the time density curve of the diluted contrast medium method resulted in smaller interpatient variability and more patients within optimal enhancement than the body weight adjusted protocol [3,14]. Including the cardiac function index in the prediction function enabled the achievement of a more precise PE value [9].…”