Improvement of determination technique for extracting centerline in coronary artery with calcification on CTA.

The present study proposes a method for improving an existing technique used for extracting the centerlines of coronary arteries with calcifications on CTA. Through the use of the improved centerline extraction method, CPR images could be depicted accurately. In the proposed method, two dynamic range compression algorithms using two ITC for blood vessel regions and calcification regions were employed. Two dynamic range compressed CTA images obtained from the two ITC were then subtracted. After that, automatic tracing to determine the centerline for creating CPR images was performed using 3D image processing equipment. The usefulness of our proposed method was confirmed by using simulated CTA of the coronary artery with calcification. We also applied the proposed method to CTA images of 39 branches in 18 cases, and to 48 segments. Our experimental results showed that automatic tracing software pre-installed in the workstation could accurately determine the centerline of the coronary artery without being affected by the existence of calcification. Furthermore, an experienced radiological technologist evaluated the CPR images obtained by the proposed method. The results showed that most created CPR images could be used as diagnostic images after a minor revision performed manually.