[Comparison of quantitative coronary arteriography using cinefilm and digital images]

Quantitative coronary arteriography using both analog data (cinefilm) and digital data was evaluated with a stenotic vessel phantom and clinical data.

A stenotic vessel phantom using contrast medium with diameters of 2, 3, 4 and 6 mm was imaged using an X-ray image intensifier. Quantitative coronary arteriography was performed to measure reference and stenosis diameters in the phantom and under clinical conditions to measure coronary artery diameters using cinefilm and digital images.

Both cinefilm and digital images were distorted at the peripheral image area, so errors were caused when the reference and stenosis were not in the same area. Measurements of diameters in the horizontal direction were larger than in the vertical and diagonal directions (p < 0.05). Reference diameters measured on digital images were larger than those on analog images (p < 0.0001). The difference in the real and measured reference diameter (2 and 3 mm) was less than 1% on digital images. The mean error in measurement of stenotic diameter measured on cinefilm images was 0.4-6.3% smaller for 0.5-4.5 mm diameter, but on digital images was 13% larger for 1 mm diameter, 18% larger for 0.75 mm diameter and 28% larger for 0.5 mm diameter. Under clinical conditions, the reference vessel diameter measured at the stenosis and the percentage stenosis were well correlated between the analog and digital images.

Reference diameters of stenotic vessels are almost the same on cinefilm and digital images, but stenotic diameters under 1 mm are larger than actual size on digital images and on cinefilm images.