CT calcium scoring is a non-invasive imaging test that quantifies coronary artery calcium (CAC) using computed tomography (CT) to assess atherosclerotic burden and predict cardiovascular risk. It is primarily used for risk stratification in asymptomatic individuals, guiding preventive strategies. The scan is performed using ECG-gated non-contrast CT, with results expressed as an Agatston score, categorizing patients into low (0), mild (1-99), moderate (100-399), and high (≥400) risk groups. A higher score indicates greater atherosclerotic burden and an increased risk of coronary artery disease (CAD) and cardiovascular events. While CT calcium scoring improves risk assessment beyond traditional clinical factors, it does not differentiate stable from unstable plaques and is not typically used in symptomatic patients. Future advancements include AI-assisted scoring and integration with predictive models to refine cardiovascular risk assessment.

1. CT CALCIUM
CT CALCIUM
SCORING
SCORING

2. Background
• Approximately 50% of acute MI occur in people without any
Approximately 50% of acute MI occur in people without any
history of CAD.
history of CAD.
• Coronary atherosclerosis is a slow progressive disease that
Coronary atherosclerosis is a slow progressive disease that
often goes unrecognized until the person develops symptoms.
often goes unrecognized until the person develops symptoms.
• What is needed is a way to identify asymptomatic people who
What is needed is a way to identify asymptomatic people who
are at high risk for CV events early in their disease process.
are at high risk for CV events early in their disease process.

3. • MI usually occurs in patients who have a
MI usually occurs in patients who have a
mild or moderate CA stenosis that
mild or moderate CA stenosis that
develops plaque rupture & leads to an
develops plaque rupture & leads to an
acute thrombosis.
acute thrombosis.
• These mild to moderate coronary lesions
These mild to moderate coronary lesions
may not cause symptoms and/or may not
may not cause symptoms and/or may not
cause enough ischemia to be picked up
cause enough ischemia to be picked up
during a routine stress test.
during a routine stress test.

4. • During the early stages of coronary
During the early stages of coronary
atherosclerosis calcium starts to
atherosclerosis calcium starts to
accumulate within the plaque.
accumulate within the plaque.
• As the atherosclerotic process progresses
As the atherosclerotic process progresses
the amount of calcification increases.
the amount of calcification increases.
• During the advanced stages of
During the advanced stages of
atherosclerosis a large amount of
atherosclerosis a large amount of
coronary calcification may be present.
coronary calcification may be present.

5. Coronary Disease Progression
Calcified Plaque Detected by CT

6. • Atherosclerosis is the only disease
Atherosclerosis is the only disease
process known to cause calcium to
process known to cause calcium to
deposit in coronary artery walls.
deposit in coronary artery walls.
• Calcification is not a degenerative
Calcification is not a degenerative
disease, it is not a part of the “normal”
disease, it is not a part of the “normal”
aging process.
aging process.
• Calcium is not found in normal CA.
Calcium is not found in normal CA.

7. • Since calcium deposits start to develop
Since calcium deposits start to develop
during the early stages of atherosclerosis
during the early stages of atherosclerosis
and if we are able to identify the
and if we are able to identify the
presence of calcium we are able to
presence of calcium we are able to
identify preclinical coronary artery
identify preclinical coronary artery
disease during the asymptomatic stage.
disease during the asymptomatic stage.
• This can allow for the implementation of
This can allow for the implementation of
early aggressive risk factor reduction.
early aggressive risk factor reduction.

8. • Calcification can be seen with fluoroscopy
Calcification can be seen with fluoroscopy
and on chest x-ray.
and on chest x-ray.
• Computed tomography allows
Computed tomography allows
quantification of this calcium.
quantification of this calcium.

9. • The amount of calcium deposited in coronary
The amount of calcium deposited in coronary
arteries is added up and a “score” is given.
arteries is added up and a “score” is given.
• The amount of calcium in the coronary
The amount of calcium in the coronary
arteries varies considerably with age and
arteries varies considerably with age and
gender.
gender.
• For this reason, coronary calcium scores are
For this reason, coronary calcium scores are
presented as percentile scores that can tell
presented as percentile scores that can tell
how much calcium you have compared to
how much calcium you have compared to
other men or women of your age.
other men or women of your age.

10. • higher than the 75th percentile is
higher than the 75th percentile is
considered high risk, irrespective of the
considered high risk, irrespective of the
score, and indicates premature
score, and indicates premature
atherosclerosis.
atherosclerosis.

11. • Unlike global risk scores such as the
Unlike global risk scores such as the
Framingham Risk Score, which provide cardio-
Framingham Risk Score, which provide cardio-
vascular risk estimates based on mean risk factor
vascular risk estimates based on mean risk factor
distributions across a population, the CCS is a
distributions across a population, the CCS is a
direct marker of atherosclerosis in an individual
direct marker of atherosclerosis in an individual
patient.
patient.
• As such, it provides an assessment of the burden
As such, it provides an assessment of the burden
of coronary atherosclerosis, reflecting the
of coronary atherosclerosis, reflecting the
integrated lifetime effect of all risk factors in an
integrated lifetime effect of all risk factors in an
individual patient.
individual patient.

12. CCS Protocol
• CAC is detected using a standardized protocol
CAC is detected using a standardized protocol
involving :
involving :
• Prospective ECG-triggered axial scanning, with
Prospective ECG-triggered axial scanning, with
a slice thickness of 3mm.
a slice thickness of 3mm.
• Standard tube voltage is 120 kV, with tube
Standard tube voltage is 120 kV, with tube
current set at 120 to 150 mAs, which should
current set at 120 to 150 mAs, which should
result in acceptably low levels of radiation
result in acceptably low levels of radiation
exposure (1 to 2 mSv).
exposure (1 to 2 mSv).

13. Methods
Methods
• Agatston Score :
Agatston Score :Traditional method
Traditional method
(EBCT : MDCT)
(EBCT : MDCT)
• Volume Score :
Volume Score : Plaque area x slice
Plaque area x slice
thickness (mm
thickness (mm³
³)
)
• Mass Score :
Mass Score : Plaque volume x mean
Plaque volume x mean
plaque density .
plaque density .

14. • The method is based on the maximum x-ray
attenuation coefficient, or CT number
(measured in Hounsfield units [HU]), and
the area of calcium deposits.
• First, calcified lesions are identified on CT
images by applying a threshold of 130 HU
to the entire image set; tissues with
densities equal to or greater than the
threshold are considered to correspond to
calcium.
Agatston Score
Agatston Score

15. • For each coronary artery, i, a region of
interest (ROI) is drawn around each
calcified lesion, j.
• The maximum CT number, CTmax ij , of
the ROI is determined and used to assign
a weighting factor, wij.
• The area, Aij, of the ROI is also
determined.

16. • The Agatston score, Sij, is computed as
the product of the weighting factor and
the area:
Sij = wij x Aij
Where :
• w ij = 1 if CTijmax 130 - 199 HU
2 if CTijmax 200 - 299 HU
3 if CTijmax 300 - 399 HU
4 if CTijmax > 400 HU

17. • The score for all lesions in all coronary
arteries is summed to determine the total
calcium burden:
Stot =  Sij

19. The Calcium Scale
The Calcium Scale
The calcium scale is a linear scale with 4
The calcium scale is a linear scale with 4
calcium score categories:
calcium score categories:
0
0 Normal
Normal
1–99
1–99 Mild
Mild
100–400
100–400 Moderate
Moderate
>400
>400 Severe
Severe

21. • Variations according to sex and ethnicity have
Variations according to sex and ethnicity have
been described.
been described.
• In the Multi-Ethnic Study of Atherosclerosis
In the Multi-Ethnic Study of Atherosclerosis
(MESA)
(MESA) of 6,110 asymptomatic patients, men
of 6,110 asymptomatic patients, men
had higher calcium levels than women, and the
had higher calcium levels than women, and the
amount and prevalence of calcium continually
amount and prevalence of calcium continually
increased with increasing age .
increased with increasing age .
• A calcium score of 175 may be average for a 65
A calcium score of 175 may be average for a 65
year old male but grossly abnormal for a 55
year old male but grossly abnormal for a 55
year old female.
year old female.
Circulation 2006;113:30–7
Circulation 2006;113:30–7

22. Distribution - men
Distribution - men
Age Ca Score
< 40 0
40 -49 0
50-54 5
55-59 36
60-64 95
65-69 201
70-74 302
> 74 521

23. Distribution - women
Distribution - women
Age Ca Score
< 40 0
40 -49 0
50-54 0
55-59 0
60-64 0
65-69 8
70-74 28
> 74 149

24. • In men, Caucasians and Hispanics had the first
In men, Caucasians and Hispanics had the first
and second highest scores, respectively; blacks
and second highest scores, respectively; blacks
had the lowest scores at the younger ages, and
had the lowest scores at the younger ages, and
Chinese had the lowest scores at the older ages.
Chinese had the lowest scores at the older ages.
• In women, Caucasians had the highest scores,
In women, Caucasians had the highest scores,
Chinese and blacks had intermediate scores, and
Chinese and blacks had intermediate scores, and
Hispanics had the lowest score except for Chinese
Hispanics had the lowest score except for Chinese
in the oldest age group.
in the oldest age group.

25. •What does CCS “0” mean?
• One may still have non-calcified
One may still have non-calcified
atherosclerotic plaque .
atherosclerotic plaque .
• Multiple studies have shown only a 0.11 %
Multiple studies have shown only a 0.11 %
annual event rate and 1.1% 10 year risk in
annual event rate and 1.1% 10 year risk in
asymptomatic patients with 0 CCS.
asymptomatic patients with 0 CCS.

26. •Advantages of CCS
• Rapid .
Rapid .
• Does not require contrast.
Does not require contrast.
• Low radiation dose .
Low radiation dose .
• Reproducible.
Reproducible.
• Powerful prognostic data.
Powerful prognostic data.
• Disadvantages of CCS :
Disadvantages of CCS :
• Cost
Cost
• Radiation exposure
Radiation exposure

27. Coronary Calcium and Clinical Outcomes
Coronary Calcium and Clinical Outcomes
• OVERALL:
OVERALL:
– 15 studies published
15 studies published
– Age range 41- 85 years old
Age range 41- 85 years old
– Approximately 15,000 patients
Approximately 15,000 patients
– All studies have reported that coronary
All studies have reported that coronary
calcium predicts CV disease events
calcium predicts CV disease events
independently of and more accurately than
independently of and more accurately than
traditional risk factors.
traditional risk factors.

28. • At 2004 a study was carried out in
At 2004 a study was carried out in
Netherlands:
Netherlands:
• From 2,032 people ages 55 to 85, with a
From 2,032 people ages 55 to 85, with a
mean age of 77, who underwent CT
mean age of 77, who underwent CT
calcium scoring between 1997 and 2000
calcium scoring between 1997 and 2000
• 0 -100 : 47%
0 -100 : 47%
• 100 -500 : 26%
100 -500 : 26%
• >500 : 27%
>500 : 27%
• The mean duration of follow-up was 2.7
The mean duration of follow-up was 2.7
years, during which time 92 subjects died
years, during which time 92 subjects died

30. • Calcium scores 101-500 :
Calcium scores 101-500 : double risk of
double risk of
mortality.
mortality.
• Calcium scores over 500 :
Calcium scores over 500 : 2.7 times
2.7 times
increased risk of mortality.
increased risk of mortality.
• The increase in mortality :
The increase in mortality :
between the lowest and the middle
between the lowest and the middle
category of calcium scores (0-100 and 101-
category of calcium scores (0-100 and 101-
500) : 12.3%
500) : 12.3%
 between the middle and the highest
between the middle and the highest
scores (101-500 and >500) : 23.7%
scores (101-500 and >500) : 23.7%

31. Integrating the Calcium Score with
Integrating the Calcium Score with
the Framingham Risk Score (FRS)
the Framingham Risk Score (FRS)
• 2004, Johns Hopkins University
2004, Johns Hopkins University
calculated the Framingham scores of 5,324
calculated the Framingham scores of 5,324
asymptomatic individuals
asymptomatic individuals
• Stratified into low-risk, intermediate-risk, and
Stratified into low-risk, intermediate-risk, and
high-risk groups
high-risk groups
― Low-risk
Low-risk is defined as a 10 year risk of < 10%,
is defined as a 10 year risk of < 10%,
― intermediate-risk
intermediate-risk is defined as a 10 year risk of 10
is defined as a 10 year risk of 10
to 20%
to 20%
― high-risk
high-risk is defined as a 10 year risk > 20%
is defined as a 10 year risk > 20%
• Underwent CT coronary artery scanning
Underwent CT coronary artery scanning

32. Framingham Score 10 yr. event risk
Framingham Score 10 yr. event risk
recalculated according to CCS range
recalculated according to CCS range

33. • CLASS IIa
CLASS IIa
• Measurement of CCS is reasonable for
Measurement of CCS is reasonable for
cardiovascular risk assessment in asymptomatic
cardiovascular risk assessment in asymptomatic
adults at intermediate risk (10% to 20% 10-year
adults at intermediate risk (10% to 20% 10-year
risk).
risk). (Level of Evidence: B) .
(Level of Evidence: B) .
2010 ACCF/AHA Guideline
2010 ACCF/AHA Guideline
RECOMMENDATIONS FOR CALCIUM
RECOMMENDATIONS FOR CALCIUM
SCORING METHODS
SCORING METHODS

34. • CLASS IIb
CLASS IIb
• Measurement of CCS may be reasonable for
Measurement of CCS may be reasonable for
cardiovascular risk assessment in persons at
cardiovascular risk assessment in persons at
low to intermediate risk (6% to 10% 10-year risk).
low to intermediate risk (6% to 10% 10-year risk).
(Level of Evidence: B)
(Level of Evidence: B)
• CLASS III: NO BENEFIT
CLASS III: NO BENEFIT
• Persons at low risk (<6% 10-year risk) should not
Persons at low risk (<6% 10-year risk) should not
undergo CCS measurement for cardiovascular
undergo CCS measurement for cardiovascular
risk assessment.
risk assessment. (Level of
(Level of
Evidence: B).
Evidence: B).

35. Detection of CAD/Risk Assessment in
Detection of CAD/Risk Assessment in
Asymptomatic Patients Without Known CAD
Asymptomatic Patients Without Known CAD
Indication
Indication Appropriate Use Score (1–9)
Appropriate Use Score (1–9)
Global CHD
Global CHD
Risk Estimate
Risk Estimate
Low
Low Intermediate
Intermediate High
High
Family history of
premature CHD
A (7)
A (7)
Asymptomatic
No known CAD
I (2)
I (2) A (7)
A (7) U (4)
U (4)
JCCT (2010) 4, 407.e1–407.e33
JCCT (2010) 4, 407.e1–407.e33
ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/
SCAI/SCMR 2010 Appropriate Use Criteria

36. The 2013 ACC/AHA Cholesterol
The 2013 ACC/AHA Cholesterol
and the 2013 ACC/AHA Risk Guidelines
and the 2013 ACC/AHA Risk Guidelines
• Created an entirely risk factor–based
Created an entirely risk factor–based
pooled cohort equation untested by
pooled cohort equation untested by
randomized clinical trials, using the same
randomized clinical trials, using the same
risk factors as the 2010 version but with
risk factors as the 2010 version but with
different weightings, now modified by
different weightings, now modified by
race.
race.
• They downgraded CCS to a Class IIb
They downgraded CCS to a Class IIb
recommendation.
recommendation.

37. Conclusion
Conclusion
• Despite the remarkable data supporting the prime
role of CCS in risk assessment of the
intermediate-risk population & considering it a
more potent predictor of CAD than risk factors for
atherosclerosis , CCS has not been incorporated
into the mainstream of clinical cardiology and has
been downgraded in the 2013 guidelines.
• As the data continue to accumulate with follow-
up periods up to 15 years, accompanied by
increasing public & physician awareness, the
importance of CCS will be more universally
accepted

38. Thank you
Thank you