Restricting motion effects in CT coronary angiography.

OBJECTIVE

Evaluation of coronary CT image blur using multi segment reconstruction algorithm.

METHODS

Cardiac motion was simulated in a Catphan. CT coronary angiography was performed using 320 × 0.5 mm detector array and 275 ms gantry rotation. 1, 2 and 3 segment reconstruction algorithm, three heart rates (60, 80 and 100bpm), two peak displacements (4, 8 mm) and three cardiac phases (55, 35, 75%) were used. Wilcoxon test compared image blur from the different reconstruction algorithms.

RESULTS

Image blur for 1, 2 and 3 segments in: 60 bpm, 75% RR interval and 8 mm peak displacement: 0.714, 0.588, 0.571 mm (1.18, 0.6, 0.4 mm displacement) 80 bpm, 35% RR interval and 8 mm peak displacement: 0.869, 0.606, 0.606 mm (1.57, 0.79,0.52 mm displacement) 100 bpm, 35% RR interval and 4 mm peak displacement: 0.645, 0.588, 0.571 mm (0.98, 0.49, 0.33 mm displacement). The median image blur overall for 1 and 2 segments was 0.714 mm and 0.588 mm respectively ( < 0.0001).

CONCLUSION

Two-segment reconstruction significantly reduces image blur.

ADVANCES IN KNOWLEDGE

Multisegment reconstruction algorithms during CT coronary angiography are a useful method to reduce image blur, improve visualization of the coronary artery wall and help the early detection of the plaque.