Chikako Fujioka RT, Presenter: Nothing to Disclose

Jun Horiguchi MD, Abstract Co-Author: Nothing to Disclose

Masao Kiguchi RT, Abstract Co-Author: Nothing to Disclose

Yun Shen PhD, Abstract Co-Author: Employee, General Electric Company

Hiroshi Fukuda MD, PhD, Abstract Co-Author: Nothing to Disclose

Katsuhide Ito MD, Abstract Co-Author: Nothing to Disclose

Minoru Ishifuro, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

The diagnostic capability of 64-slice CTA for coronary artery stenosis has become accepted, however, factors affecting its accuracy are not fully elucidated. The purpose of this study is to demonstrate factors influencing diagnostic accuracy of stenosis measurement in 64-slice CT coronary angiography.

Coronary plaque models of two diameters (3mm and 4mm) with three stenosis levels (low, medium, high) attached to a pulsating cardiac phantom were scanned in various conditions. Parameters in the experiment included heart rates (HRs, 50 to 125bpm), cardiac reconstruction algorithms (half, multi-segmented), plaque CT values (35HU, 100HU and 400HU), intracoronary arterial enhancement (150HU, 250HU, 350HU and 450HU) and plaque shape (D-shaped, centric and eccentric). Stenosis measurement was performed using full width at half maximum of CT density profiling curves.

Low HRs (50 to 65 bpm) with half reconstruction & high and stable HRs (70 to 95bpm) with multi-segmented reconstruction algorithms showed good measurements, while HRs over 95bpm with any reconstruction showed poor measurements. Large difference of CT densities between plaque and intracoronary arterial enhancement was advantageous for accurate measurements. Stenosis levels and plaque shapes were not significant factors for accurate measurements. A larger diameter (4mm) resulted in more accurate measurements than a smaller diameter (3mm).

A low HR, improved temporal resolution, large difference between plaque density and intracoronary arterial enhancement & plaque in large arteries are advantageous factors for the accurate measurement of coronary artery stenosis.

For accurate measurement of coronary artery stenosis, low heart rate, improved temporal resolution, large difference between plaque and arterial densities & large coronary artery play vital factors.

Fujioka, C, Horiguchi, J, Kiguchi, M, Shen, Y, Fukuda, H, Ito, K, Ishifuro, M, et al, , Factors Influencing Diagnostic Accuracy of Stenosis Measurement in 64-slice CT Coronary Angiography.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6007907.html