This document discusses the role of MDCT in detecting coronary calcifications. It describes how calcium scoring is performed using CT scans and defines scoring levels from none to severely elevated. Examples are provided of mild, moderate, and markedly elevated calcium scores in single and multiple vessels. While calcium scoring provides a noninvasive risk assessment, accuracy of CT angiography is reduced in patients with high calcium scores due to degraded images.

1. Role of MDCT in Coronary
Calcifications
Dr. Muhammad Bin Zulfiqar
PGR IV FCPS Services Institute of
Medical Sciences / Hospital
radiombz@gmail.com
Special Thanks :Clinical Cardiac CT Anatomy and Function Ethan J. Halpern, MD

2. 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.

3. Coronary Calcium Score
• No calcium
• Mildly elevated—0-100
• Moderately elevated—100-400
• Severely elevated—> 400

5. • 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).

6. • 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.

7. 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

8. 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

9. 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.

10. 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

11. 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.

12. 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 algorithm
Continued

13. 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

14. 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

15. 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

16. 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

17. 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.

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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.

24. 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.