❤️ Cardiac CT Protocols

Protocols for coronary CTA, calcium scoring, and functional cardiac imaging.

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Quick Reference

Protocol	Primary Goal	Contrast Timing	Coverage	Special Notes
Coronary CTA	Native coronary arteries	Arterial (Bolus Tracked)	Heart (Carina to Apex)	HR < 60 bpm. Nitro + Beta blockers critical.
Post-CABG	Graft patency (LIMA/RIMA/SVG)	Arterial	Full Chest (Lung apices to Apex)	Extended coverage for grafts.
Gated Chest	Routine coronary / Structure	Arterial	Heart	Standard cardiac or root anatomy protocol. Optional stent delay post TEVAR.
TAVR	Aortic valve + Access	Split: Gated Chest + Flash AP	Chest + Abdo/Pelvis (Femoral heads)	Valve sizing and access planning.
TMVR	Mitral valve + Access	Arterial Chest + 90s Delay CAP	Chest + Abdo/Pelvis	No dose modulation on chest.
TTVR	Tricuspid valve + Access	Arterial Chest + 90s Delay CAP	Chest + Abdo/Pelvis	No dose modulation on chest.
Post-Sternotomy	Re-entry planning	Arterial + Flash AP + 60s Venous	Chest + Abdo/Pelvis	Venous phase critical for retrosternal adherence.
LA Mapping	PV isolation planning	Arterial + 40s Delay	Pulmonary Veins (Limited)	Focus on PV ostia and LA appendage.

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• Cardiac Gating Tips

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  Target HR: <60 bpm for coronary CTA If HR > 75 bpm despite beta blockers, scan targeting end systole.

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• Cardiac Medications

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  Metoprolol 5 mg IV PRN (max 15 mg) Contraindications: Severe asthma/COPD, Heart block (2nd/3rd degree), SBP <100 mmHg

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  Nitroglycerin 0.4 mg SL Timing: 3-5 min before scan Contraindications: Recent PDE5 inhibitor (< 48hrs), severe aortic stenosis, SBP <100

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Contrast Timing

\(\text{Scan Delay} = \text{Scan Time} - 5 \text{ seconds}\)

Low Contrast Dose Calculation

Max Contrast = \(2*\left[\frac{\text{Patient Weight}}{75 \text{ kg}} * \text{eGFR}\right]\)