Coronary CTA
Last Updated: 2026-02-02 Author:
-
1. Clinical Summary
Series Phase Coverage Calcium Score N/A Carina → Below heart Gated CTA Bolus tracked 2cm above LAD → 2cm below heart apex - Intermediate chest pain
- Suspected infarct
- Coronary artery dissection or aneurysm
- Anomalous coronary artery
- Stent patency
-
2. Patient Prep
- Position: Supine feet-first
- NPO Status: NPO 2-4 hours
- Pre-Medication:
- HR < 60 target.
- Metoprolol 5mg IV increments up to 15mg. Metoprolol contraindications include sBP < 100, 2nd/3rd degree heart block, and inhaler dependent asthma.
- Nitroglycerin 0.4mg SL 5 minutes before scan. Nitroglycerin contraindications include sBP < 100, PDE5 inhibitors within 48 hrs, severe aortic stenosis.
-
3. IV Contrast & Injection
Parameter Value Agent Isovue 370 Volume 1.1 mL/kg Flow Rate 4-5 mL/s Duration 20s Timing Method Bolus Tracking ROI Placement Ascending aorta Trigger (HU) 200 HU Use full dose if GFR > 30
If GFR < 30
Max Contrast = \(2*\left[\frac{\text{Patient Weight}}{75 \text{ kg}} * \text{eGFR}\right]\)
-
4. Special Notes
- Non-valsalva breathing technique, cardiac breathing instruction. Put in study notes if patient unable to follow breathing instructions. | If high HR variability, can trigger by millisecond (200ms - 450 ms pulse range). Revolution CT is better for Afib. | Target End diastole if HR < 65bpm. Target End systole if HR > 86bpm. Target End diastole to End systole if HR 66 - 75 bpm
- 20G IV minimum. Check for metoprolol or nitroglycerin contraindications. Nitro is priority over metoprolol if BP is borderline.
Safety First
- Renal Function: Verify eGFR > 30
- Allergy: Check allergy history
- Calculate Agatston score. Give CAD-RADS score. Check function look for potential focal wall motion abnormalities
- Full chest coverage essential. Extended FOV. Low pitch for retrospective gating
| Series Name | Start Location | End Location | Delay | Slice Thickness | Notes |
|---|---|---|---|---|---|
| Calcium Score | Carina | Below heart | N/A | 3 mm | Calcium score |
| Gated CTA | 2cm above LAD | 2cm below heart apex | Bolus tracked | 0.5-0.625 mm | Retrospective gating |
| Plane | Acquisition | FOV | Thickness/Increment | Kernel | IR Strength | Notes |
|---|---|---|---|---|---|---|
| Axial | Calcium score | Heart | 3 mm/3 mm | Standard | 3 | For Agatston score calculation |
| Axial | Calcium score | Chest | 1.5 mm/1.5 mm | Lung | 3 | Lung FOV for Extracardiac findings |
| Axial | Gated CTA | Heart | 0.625 mm/0.625 mm | Cardiac | 3 | Native coronary assessment |
| 3D VR | Gated CTA | Heart | 0.5 mm source | Cardiac | 3 | MPRs by 3D lab |