Coronary CT - edge correction

Technique

• patient premedication: beta blocker and nitrates

• acquisition method: step and shoot (prospective acquisition)

• contrast injection protocol: triphasic injection

• image reconstruction with edge correction

Findings

• normal coronary origins and proximal courses

• right coronary dominance strong double intermedius branch

• corkscrew-like tortuous terminal vessels

Plaque burden:

• calcium score (according to Agatson, not shown): 1601

• segment involvement score (SIS): 10 segments

Right coronary artery (RCA): gives rise to PDA and RPLB

• multiple calcified plaques and severe calcifications in the distal segment

• low-grade stenosis (25-49%) in the proximal segment by an odd-looking plaque versus artifact in the transition zone of the cranial and middle sequential axial scan rotations

• calcified hardly assessable stenosis in the middle segment and moderate stenosis (50-69%) in the distal segment

• no relevant plaques or stenoses in the posterior descending artery (PDA) and posterolateral branch (RPLB)

Left main: quadrifurcation with a strong and a thin ramus intermedius branch

• no plaques or stenosis

Left anterior descending artery (LAD): one diagonal branch

• multiple calcified plaques

• plaque-related moderate stenosis in the proximal segment (50-69 %)

• small diagonal branch with a thin lumen and no relevant plaques or stenoses

Ramus intermedius: duplicate with a thin proximal and strong branching distal branch

• plaque-related moderate stenosis (50-69%) proximally at the origin of the dominant branch

Circumflex artery (CX): two obtuse marginal branches

• multiple calcified plaques

• low-grade plaque-related stenoses (25-49%) in the proximal and distal thirds

• obtuse marginal branches with no plaque or stenoses

Impression

• moderate coronary stenoses (50-69%) in the proximal LAD and the origin of the dominant ramus intermedius branch and questionable further significant stenosis in the distal part of the RCA

• extensive overall plague burden

• quadrifurcation of the left main with duplicate ramus intermedius artery

• corkscrew-like tortuous terminal vessels indicating hypertensive disease

Exam courtesy: Yvonne Kühn (radiographer)

Technique

• image reconstruction without edge correction and without motion correction

Findings

Without edge correction, the transition of the three sequential axial steps can be identified clearly as a sharp edge, visible in the coronal and sagittal multiplanar and 3D reconstructions.

The odd-looking plaque in the proximal third of the right coronary artery with possible high-risk features looks much less conspicuous in this image reconstruction. It is consistent with an artifact in the standard reconstruction mode. The plaque-related stenosis in the middle segment of the right coronary artery can now be better assessed in the area of the transition zone and rated as moderate stenosis.

In the standard algorithm with 'edge correction', it looks rather blurry.