Coronary Artery Calcium Data and Reporting System

Coronary Artery Calcium Data and Reporting System (CAC-DRS) is a structured reporting scheme for all non-contrast CT scans in the evaluation of coronary artery disease, which can help in communication between clinicians and radiologists. These guidelines have been recommended by the Society of Cardiovascular Computed Tomography and Society of Thoracic Radiology .

This system will apply to all dedicated coronary artery calcium (CAC) scans and all nongated non-contrast chest CT. Radiologists can interpret both visually and quantitatively with the Agatston score.

Interpretation categories and management recommendations

Agatston Score (A)

CAC-DRS A0

  • CAC score = 0  
  • very low risk
  • statin generally not recommended (excluding familial hypercholesterolemia).

CAC-DRS A1:

  • CAC score = 1–99
  • mildly increased risk
  • moderate-intensity statin

CAC-DRS A2

  • CAC score = 100–299
  • moderately increased risk
  • moderate to high-intensity statin + acetylsalicylic acid (ASA) 81mg

CAC-DRS A3

  • CAC score > 300 
  • moderately to severely increased risk
  • high intensity statin + ASA  81mg
Visual Score (V)

The visual score may be utilized for non-contrast non-gated studies but should not be applied to gated CAC scans.

CAC-DRS V0

  • CAC visual score = 0  
  • very low risk 
  • statin generally not recommended (excluding familial hypercholesterolemia)

CAC-DRS V1

  • CAC visual score = 1
  • mildly increased risk
  • moderate-intensity statin

CAC-DRS V2: 

  • CAC visual score = 2
  • moderately increased risk
  • moderate to high-intensity statin + ASA 81mg

CAC-DRS V3: 

  • CAC visual score = 3
  • moderately to severely increased risk
  • high intensity statin + ASA 81mg

Example reports

By comparison, the Agatston score in this scale uses a different grading of calcification (1-300), as well as an additional modifier (N). Additional modifier (N) is used to characterize the number of affected coronary arteries.

Agatston Score (A)
  • CAC-DRS A0: CAC 0
  • CAC-DRS A1/N3: CAC 1–99 in LM, LAD and LCx  
  • CAC-DRS A2/N3: CAC 100–299 in LAD, LCX and RCA
  • CAC-DRS A3/N4: CAC > 300 in LM, LAD, LCx and RCA
Visual Score (V)
  • CAC-DRS V0: CAC 0
  • CAC-DRS V1/N3: CAC 1 in LM, LAD and LCx  
  • CAC-DRS V2/N3: CAC 2 in LAD, LCX and RCA
  • CAC-DRS V3/N4: CAC 3 in LM, LAD, LCx and RCA

Incidental findings in CAC-DRS reports

  • pericardium, e.g. pericardium effusion, pericarditis
  • ascending aorta, e.g. normal less than 4 cm
  • descending aorta, e.g. normal less than 3 cm
  • pulmonary trunk, e.g.normal less than 29 mm
  • extra-coronary calcification, e.g. aortic valve or wall calcification, mitral valve calcification
  • other findings, e.g. lung nodule

See also