Cardiac CT Recognition Pattern

Systematic approach to interpreting coronary CT angiography (CCTA) with key anatomical landmarks and pathological findings

Enhance your radiology skills with our app!

Download Radiology Assistant App

1. Basic Principles

A. Standard Windows

• • Soft tissue window:
  - WW 350-400, WL 40-60
  - Assess myocardium, chambers
• • Vessel window:
  - WW 800, WL 300
  - Coronary artery evaluation
• • Lung window:
  - WW 1500, WL -600
  - Lung parenchyma assessment

B. Acquisition Phases

• • Non-contrast:
  - Calcium scoring
  - Baseline attenuation
• • Angiographic phase:
  - 60-80% R-R interval
  - Coronary artery evaluation
• • Delayed phase:
  - For viability (if performed)

2. ABCDE Systematic Approach

Step

Assessment

Key Elements

A

Aorta & Artifacts

Motion, beam hardening, stair-step

B

Bypass grafts

LIMA, RIMA, SVG patency

C

Coronary arteries

LM, LAD, LCx, RCA

D

Densities

Plaque characterization

E

Everything else

Chambers, valves, lungs

3. Coronary Artery Evaluation

A. Coronary Segments (17-segment model)

Artery

Segments

LM

5 (ostium, bifurcation)

LAD

6-10 (prox, mid, distal, diagonals)

LCx

11-15 (prox, distal, OM branches)

RCA

1-4 (prox, mid, distal, PDA)

B. Plaque Characterization

Type

HU Range

Features

Calcified

>130 HU

Bright, blooming

Non-calcified

30-130 HU

Soft, may be vulnerable

Low-attenuation

<30 HU

Necrotic core, high risk

4. Stenosis Grading

Grade

Diameter Reduction

Clinical Significance

Minimal

<25%

Non-obstructive

Mild

25-49%

Non-obstructive

Moderate

50-69%

Possibly ischemic

Severe

70-99%

Likely ischemic

Occluded

100%

Total occlusion

B. High-Risk Plaque Features

• • Low attenuation plaque:
  - <30 HU
• • Positive remodeling:
  - RI >1.1
• • Napkin-ring sign:
  - Ring-like enhancement
• • Spotty calcification:
  - <3mm calcifications

5. Cardiac Chambers & Function

A. Chamber Measurements

Chamber

Normal Diameter (cm)

LV

4.0-5.5 (end-diastole)

RV

<4.5 (mid cavity)

LA

<4.0 (AP diameter)

B. Wall Motion Abnormalities

• • Hypokinesis:
  - Reduced wall motion
• • Akinesis:
  - Absent wall motion
• • Dyskinesis:
  - Paradoxical motion

6. Non-Coronary Findings

A. Great Vessels

• • Aortic aneurysm:
  - >4.5cm ascending
  - >3cm descending
• • Pulmonary embolism:
  - Filling defects

B. Pericardium

• • Effusion:
  - >50ml fluid
• • Constriction:
  - Thickened pericardium

7. CCTA Reporting Template

1. 1. Technique:
   - Scanner type, slice thickness
   - Contrast volume, timing
2. 2. Coronary arteries:
   - Dominance
   - Segment-by-segment analysis
   - Stenosis severity
   - Plaque characteristics
3. 3. Cardiac chambers:
   - Size and function
   - Wall motion abnormalities
   - Ejection fraction (if available)
4. 4. Great vessels:
   - Aortic dimensions
   - Pulmonary arteries
5. 5. Incidental findings:
   - Lungs, mediastinum
   - Upper abdomen

Always correlate with clinical history and prior studies. For coronary evaluation, use multiplanar reconstructions and curved reformats. Report CAD-RADS category when applicable. Note any artifacts affecting interpretation. For significant stenosis (>70%), consider correlation with functional testing. Follow up suspicious non-cardiac findings as appropriate.

Get more radiology resources in our app!

Download Radiology Assistant App Now