Calcified plaque may be missed on coronary CT angiography (cCTA) with highly concentrated iodinated contrast material (CM) at low kV settings.
We analyzed the impact of different iodine density CM at varying tube potential for the assessment of calcified plaques on cCTA images.
Methods and Materials
164 consecutive patients with suspected coronary artery disease underwent non-enhanced calcium scoring (CaSc) at 120 kV followed by cCTA with topogram-based automated kV selection on third- or second-generation dual-source CT.
Based on prior observations 37 patients were injected diluted CM with a resulting iodine concentration of 280 mg/ml (group1) between September 2015 and March 2016 whereas 127 patients were injected undiluted CM with an concentration of 400 mgI/ml (group2).
Amount (50 ml) and flow rate (5 ml/s) were kept constant.
The sensitivity of cCTA for...
97 patients (59%) had calcified plaques on CaSc,
78 patients of group 2 and 19 patients of group 1.
The overall sensitivity of cCTA for detection of calcified plaques was 79% in group 1 and 73% in group 2.
Sensitivity for patients examined at 70 kV was significantly higher with diluted CM (70% vs.
There was no significant difference in sensitivity at 100 and 120 kV in both groups (100% and 82% in group 1 and 2,
The overall median luminal contrast density...
The combination of highly concentrated CM and 70 kV tube potential reduces the detectability of calcified plaques.
In order to preserve reliable information on relevant calcifications,
cCTA at 70 kV should be performed with CM with lower iodine concentration.
If undiluted CM is used,
100 kV tube potential should preferably be chosen.