Role of MDCT in Coronary Calcifications

Dr. Muhammad Bin ZulfiqarPGR IV FCPS Services Institute of Medical

Sciences / Hospitalradiombz@gmail.com

Special Thanks :Clinical Cardiac CT Anatomy and Function Ethan J. Halpern, MD

CT Technique for Calcium Scoring

• Calcium scoring is based on the identification of high density material within the coronary circulation on a non contrast CT scan.

• Once the location of coronary calcium is identified on a CT examination, an automated program is used to compute a calcium score. The Agatston method has been traditionally used to score the amount of coronary calcium with CT.

Coronary Calcium Score

• No calcium• Mildly elevated—0-100• Moderately elevated—100-400• Severely elevated—> 400

• Fig. 1.1 Coronary calcium and calcium scoring. Axial image through the level of the left anterior descending artery demonstrates the presence of calcification in the proximal portion of this vessel (arrows).

• Coronary calcification versus annular calcification. (Right) Noncontrast axial image at the level of the left main coronary artery demonstrates focal calcification within the left coronary artery (arrow), as well as focal calcification of the aortic root (arrowhead). (Left) Axial image at the level of the mitral valve demonstrates focal calcification of the left anterior descending artery (white arrowhead), as well as focal calcification of the mitral annulus (black arrowhead). The mitral annulus is deep to the circumflex artery, which is found along the left atrioventricular groove.

Mild Calcification of LCA

• Mild calcification of the left coronary artery without significant stenosis.

• Calcium scoring study demonstrates calcification in the left main coronary artery, as well as the proximal left anterior descending artery (LAD). Continued

Mild Calcification of LCA

• Calcification in the left main and LAD arteries is color-coded by the automated calcium detection algorithm. No other coronary calcification was noted. The total Agatston calcium score of 116.4 suggests an increased risk of a cardiac event relative to an individual with no coronary calcium. Continued

Mild Calcification of LCA

• CT angiogram performed following the calcium scoring study demonstrates calcified plaque in the proximal LAD (arrow) without significant stenosis in the LAD.

Two Vessel Coronary Calcium

• Two-vessel coronary calcium without significant stenosis.• (Right) Axial image through the proximal left coronary artery

demonstrates the presence of calcification in the proximal left anterior descending artery (LAD).

• (Left) LAD calcium is color-coded by the automated detection algorithm. Continued

Two Vessel Coronary Calcium

• (Right) Axial image at a slightly lower level demonstrates calcium within the mid circumflex artery along the left atrioventricular groove. Note the difference in position between this circumflex calcification and the mitral annular calcification.

• (Left) Calcium in the circumflex artery is color-coded. Although the calcified plaque involves two vessels, the total calculated Agatston calcium score of 70.2.

Moderate Three Vessel Calcifications

• Moderate three-vessel calcification without significant stenosis.• (Right) Axial image demonstrates heavy calcification in the proximal left

anterior descending artery (LAD). • (Left) LAD calcium is color-coded by the automated detection algorithmContinued

Moderate Three Vessel Calcifications

• (Right) A small calcified plaque is present in• the proximal right coronary artery (RCA). • (Left) RCA calcium is color-coded by the

automated detection algorithm Continued

Moderate Three Vessel Calcifications

• (Right) Axial image at the level of the RCA origin (arrow) demonstrates the calcium within the circumflex artery.

• (Left) Circumflex calcium is color-coded by the automated detection algorithm. The overall Agatston calcium score of 418.5 suggests that the risk of a coronary event is significantly higher compared with that of a patient without coronary calcium.

Continued

Moderate Three Vessel Calcifications

• CT angiogram of the left coronary artery with orthogonal curved maximum intensity projection (MIP) reconstructions demonstrates calcified plaque along the proximal LAD, without significant stenosis. Positive remodeling is demonstrated in

• the proximal LAD (arrow).

Continued

Moderate Three Vessel Calcifications

• Orthogonal curved MIP images of the RCA demonstrate calcification in the proximal portion of this vessel (arrow), without significant narrowing.

Continued

Moderate Three Vessel Calcifications

• Orthogonal curved MIP images through the circumflex artery, again demonstrate the presence of focal calcified plaque (arrow) with positive remodeling, and without significant stenosis.

Markedly elevated calcium score

• Markedly elevated calcium score with associated stenosis in the right coronary artery (RCA). (Right) Axial image demonstrates extensive calcification of the proximal left coronary artery and left anterior descending artery (LAD). (Left) LAD calcium is color-coded.

Continued

Markedly elevated calcium score

• (Right)Axial image at a slightly lower level demonstrates calcium within both the LAD and circumflex arteries. (Left) Calcium within the LAD and circumflex arteries is color-coded. Continued

Markedly elevated calcium score

• (Right) Axial image at a slightly lower level demonstrates calcification in the LAD, circumflex, and RCA. Mild calcification is also identified in the posterior mitral annulus (arrowhead). (Left) Calcium in the three major coronary arteries is color-coded. The mitral annular calcification is labeled in pink and is not included in the calcium score. The total Agatston calcium of 2726.1 is markedly elevated, suggesting increased risk for a coronary event.

Continued

Markedly elevated calcium score• Orthogonal curved

maximum intensity projection (MIP) images of the LAD obtained with CT angiography demonstrate diffuse calcification. Calcified plaque appears to fill most of the LAD lumen on short axis-images (arrowhead). Conventional coronary angiography demonstrated only mild disease in the LAD.

Continued

Markedly elevated calcium score• Orthogonal curved MIP

images through the circumflex artery demonstrate diffuse calcified plaque. Short-axis images demonstrate extensive calcified plaque (arrows), as well as noncalcified plaque with ulceration (arrowhead). Conventional arteriography demonstrated only mild disease in the circumflex artery.

Continued

Markedly elevated calcium score• Markedly elevated calcium score

with associated stenosis in the right coronary artery (RCA). Orthogonal curved MIP images of the RCA demonstrate diffuse calcified and noncalcified plaque. Of the three major coronary arteries, the RCA was the least suspicious for significant stenosis on CT angiography.

• Nonetheless, conventional arteriography demonstrated moderate to severe stenosis in the midportion of the RCA. This area was treated by angioplasty. The accuracy of coronary CT angiography is degraded in patients with markedly elevated calcium scores.

Take Home Message

• Coronary artery calcium scoring provides a quick, noninvasive method for risk assessment of coronary heart events.

• Calcium scoring is most appropriate in the asymptomatic population with a coronary heart disease risk of 10 to 20% based on the Framingham risk calculation or in patients with other risk factors not considered in the Framingham analysis.

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