Quadrifurcation of the left main stem

Technique

• patient premedication: beta blocker and nitrates

• acquisition method: step and shoot (prospective acquisition)

• contrast injection protocol: triphasic injection

• image reconstruction:

  • standard with and without edge correction

  • dual-energy maps (see next study)

Findings

• ordinary coronary origins and proximal courses

• right coronary arterial dominance

• corkscrew-like tortuous terminal vessels

• mitral annular calcification

Plaque burden:

• calcium score (according to Agatson, not shown): 59

• segment involvement score (SIS): 1 segment

Right coronary artery (RCA): gives rise to posterior descending artery and posterolateral branch

• no plaques or stenoses in the proximal, middle and distal segments

• no plaques or stenoses in the PDA and RPLB

Left main: quadrifurcation, otherwise inconspicuous

Left anterior descending artery (LAD): one diagonal branch

• mixed plaque in the proximal segment near the origin of the ramus intermedius

• otherwise no plaques or stenoses

Ramus intermedius: two intermedius artery branches supplying the lateral wall

• no plaques or stenoses

Circumflex artery (Cx): one marginal branch

• no plaques or stenoses in the main epicardial vessel and the marginal branch

Impression

• mild amount of plaque - CAC-DRS A1/N1 and V1/N1

• minimal non-obstructive coronary artery disease - CADRADS1/P1

• mitral annular calcification

Exam courtesy: Yvonne Kühn (radiographer)

MonoE 40 & 55 keV

• MonoE 40 keV & 55 keV images, synthesized at a level of 40 keV and 55 keV respectively

• reconstructions in a soft tissue algorithm with a window setting C:800 W:2000

• monoenergetic images at 55 keV allow for better differentiation between calcified plaque and vessel lumen compared to 40 keV with the same window settings

Conventional + MonoE 40 overlay

• conventional images, reconstructed with a standard soft tissue filter and supplemented with a color-coded MonoE 40 keV overlay ranging from -600 to 1400 (C:400 W:2000)

• the non-calcified portion of the plaque is nicely visible in this setting whereas calcium is not

Iodine no Water

• iodine images at a window level C:12 W:24

Virtual non-contrast images

• virtual non-contrast images (VNC) reconstructed with a window setting C:100 W:600

Iodine no water + virtual non-contrast overlay

• iodine no water images obtained by subtracting water from contrast-enhanced images with a color-coded virtual non-contrast overlay (VNC) ranging from -200 to 400 (C:100 W:600)

• this setting nicely depicts calcified plaques and the mitral annular calcification

• however, it must be taken into account that non-calcified plaque is less easily seen than with the standard reconstruction algorithm