Zepa Yang BS, Presenter: Nothing to Disclose

Hyeongmin Jin, Abstract Co-Author: Nothing to Disclose

Jong Hyo Kim PhD, Abstract Co-Author: Nothing to Disclose

To evaluate the accuracy of iterative reconstruction (IR) CT in the quantification of small lesions such as plaque size measurement in coronary artery.

A phantom was created which mimics coronary artery containing various size and types of plaques. PMMA tubes of 3mm - 8mm were used for artery, calcium equivalent stones of 1mm - 4mm size and porcine fat of 1mm size were used to mimic calcified and fatty plaques. CT scans were performed on the phantom without and with iodine contrast filling, and CT images were reconstructed with FBP, ASIR, MBIR techniques. Plaque volumes were measured by applying thresholding technique at a 5 times magnified and interpolated images.

Measured values for the small calcified plaque of 2.65mm3 size were 1.98mm3,1.93mm3, and 2.31mm3, for medium calcified plaque of 14.52mm3 size were 11.49mm3,11.37mm3, and 13.10mm3, and for large calcified plaque of 32.07mm3 size were 27.06mm3,27.43mm3, and 29. 91mm3 in FBP, ASIR, MBIR CTs, respectively. Compared to calcified plaque, both 9 mm3 and 4 mm3 fatty plaque sizes were measured faithfully within 10% error in all three reconstruction CTs.  

Our study shows that IR CT potentially provides improved quantification accuracy in measurement of plaque size in coronary artery depending on the type of IR technique.

While coronary artery plaque size is known as a strong predictor for adverse cardiac events, the limitation of measurement accuracy was the problem, our study suggests IRCT has a potential to overcome.

Yang, Z, Jin, H, Kim, J, Does Iterative Reconstruction CT Improve Lesion Quantification Accuracy? A Phantom Study for Plaque Size Measurement in Coronary Artery.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12036534.html