Coronary artery calcium scoring (CACS) is widely used to access the patients risk of coronary artery disease.
Althogh the radiation dose at CACS is relatively low compared to the coronary artery CT angiography,
efforts must be made to reduce it further. Recently introduced iterative reconstruction (IR) technique can reduce the tube current and thus radiation dose at CT without sacrifising the image noise compared with filtered back projection (FBP).
Though strong IR level may affect image...
Methods and Materials
We enrolled 65 patients with suspected coronary artery disease.
We obtained two consecutive scans for CACS.
One was acquired at the normal tube current with FBP reconstruction and the other was at a low tube current with strong IR.
Scan details are shown in the table 1. Among them we extracted the 34 patients with no motion artifact in both CAC scan and performed the CACS with Agatston,
volume and mass methods.
Then we calculated the percentage difference between FBP and IR. Percentage...
The figure 1 and 2 are for the representative images. In fig.1 image noise was markedly improved by the aplication of IR. In fig.2 green dots suggest calcification automatically identified by the scoring software. In FBP image,
there were scattering green dots caused by image noises and mimicking calcification. Radiation dose and CACS result are shown in the table 2. Radiation dose for the IR with low tube current was significanlt lower than that for the FBP with normal tube current....
By combiing IR,
CACS can be performed at a markedly lower radiation dose without losing the compatibility of CACS with FBP.
1) Am J Roentgenol 2008; 190 : 1561-1568 2) Korean J Radiol 2009; 10 : 340-346