Multivessel coronary artery disease

Technique

• patient premedication: beta blocker and nitrates

• acquisition method: step and shoot (prospective acquisition)

• contrast injection protocol: triphasic injection

• standard image reconstruction with and without edge correction

Findings

• normal coronary origins and proximal courses

• right coronary arterial dominance

• occluded right coronary artery

• posterolateral collateral network

Plaque burden:

• calcium score (according to Agatson, not shown): 116

• segment involvement score: 3-5

Right coronary artery (RCA): gives rise to posterior descending artery (PDA)

• long occlusion with intermittent perfusion in the middle and distal segment

• posterior descending artery and posterolateral branches are fed via collaterals

Left main: inconspicuous

Left anterior descending artery (LAD): one diagonal branch

• eccentric plaque with high-risk features (napkin-ring sign & spotty calcium) and high-grade stenosis (D:>70%; A:~90%) in the proximal segment

• no plaques or stenoses of the diagonal branch

Ramus intermedius: inconspicuous

Circumflex artery (CX): one large marginal branch (OM), thin posterolateral branch (PLA)

• calcified plaque with low-grade stenosis proximally

• no plaques or stenosis of the marginal branch

• moderate stenosis (D: 50-69%; A: 75-85%) and high-grade stenosis (D: >70%; A: >90%) of the posterolateral branch

• network of thin collaterals on the posterolateral wall

Impression

Obstructive coronary artery disease (3-vessel disease) with the following:

• chronic occlusion of the right coronary

• high-grade stenosis of the proximal LAD due to a high-risk plaque

• low-grade stenosis of the proximal CX and further moderate and high-grade stenosis of the posterolateral branch

• mild to moderate amount of coronary plaque

Exam courtesy: Silva Reinecke & Yvonne Kühn (medical imaging technologists)

Iodine no water + virtual non-contrast overlay

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

MonoE 40, 55, 70 and 85 keV axial and curved multiplanar reconstructions

• virtual monoenergetic images (VMI), synthesized at 40, 55, 70 and 85 keV, respectively

• reconstructions in a soft tissue algorithm with a window of C:800 W:2000 of the axial images

• window setting for the curved multiplanar VMI was adjusted to account for brightness:

  • monoE 40: C:800 W:2000

  • monoE 55: C:600 W:1500

  • monoE 70: C:400 W:1000

  • monoE 85: C:200 W:500

Conventional + MonoE 40 overlay

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

The virtual monoenergetic images at very low keV 40 (MonoE40) have better contrast resolution and higher signal-to-noise ratio but they give the impression of having a slightly lower spatial resolution. The images with a low keV setting at 40 keV and 55 keV as well as the MonoE 40 overlay offer an interesting aspect of the stenotic and occluded segments.

Right coronary artery (RCA):

• long-range occlusion with filling of the periphery and distal branches from the left side

Left anterior descending artery (LAD):

• high-grade stenosis and antecedent low-grade stenosis in the proximal segment

Circumflex artery (CX):

• high-grade stenoses of the origin and further downstream of the posterolateral branch

Image courtesy: Dr Frank-Peter Held (cardiologist)

Heart rate: 79 bpm

Image quality: mild to moderate respiratory artifacts, otherwise no limitations

Morphology and functional analysis (endo-volume):

• LV-EDVI: 94 mL/m²

• LV-ESVI: 50 mL/m²

• LV-SVI: 43 mL/m²

• LV-EF: 46%

• cardiac output: 6.4 L/min

• cardiac index: 2.9 L/min/m²

• LV-ED wall mas index (without papillary muscles): 53 g/cm

• septum thickness: 7 mm

Findings:

Mild hypokinesia in basal and midventricular inferoseptal, inferior and inferolateral segments.

Subendocardial late gadolinium enhancement (transmural extent ~25-50%) in the basal inferoseptal, inferior and inferolateral segments and the midventricular inferior segment.

Associated increased extracellular volume as well as mildly elevated T1 and T2 mapping values at the upper edge of the normal based on local reference range (z-score ~2).

• T1 mapping native: 1056-1062 ms (infarcted myocardium); 986-1030 (remote myocardium)

• extracellular volume (ECV): >32% (infarcted myocardium); 24-30% (remote myocardium)

• T2 mapping: 55 +/-6 ms (infarcted myocardium); 48 +/-6 ms (remote myocardium)

Normal reference ranges based on local data:

• native T1: 940-1060 ms; ECV: >32%; T2: 44-56 ms

No intracavitary thrombi.

No valvular pathology.

Visually normal atrial size.

No pericardial effusion.

Impression:

Cardiac MRI findings are consistent with a chronic myocardial infarction with subendocardial myocardial scarring of the inferior wall and remaining viable myocardium.

Exam courtesy: Kathrin Brandner & Diana Buchardt (medical imaging technologists)