Cardiac CT Imaging Revision Sheet

##1. 📌 Essentials

• ECG gating synchronizes image acquisition with cardiac cycle to reduce motion artifacts.
• Heart rate < 65 bpm is ideal for optimal image quality.
• Dual-source CT improves temporal resolution (~75 ms), beneficial at high heart rates.
• Contrast bolus peaks at 15-20 seconds; timing is critical for coronary artery visualization.
• Prospective ECG gating offers lower radiation dose compared to retrospective gating.
• Motion and blooming artifacts impair image clarity; mitigated via gating, high temporal resolution, and reconstruction.
• Dose reduction strategies include ECG-based modulation, lower kVp/mA, and iterative algorithms. Wide-detector CT captures the entire heart in a single rotation, reducing scan time.
• High contrast-to-noise ratio achieved with lower kVp (80-100) but requires dose adjustments.
• Beta-blockers are often administered to control heart rate before scanning.

2. 🧩 Key Structures & Components