High-pitch coronary CT angiography with third generation dual-source CT: limits of heart rate

Area of Science:

• Medical Imaging
• Cardiovascular Radiology
• Computed Tomography

Background:

• Coronary artery imaging with computed tomography angiography (CTA) requires precise patient heart rate control.
• High-pitch, dual-source CT scanners offer faster scan times but may be more sensitive to cardiac motion.
• Optimizing heart rate (HR) and heart rate variability (HRV) is crucial for diagnostic image quality in coronary CTA.

Purpose of the Study:

• To determine the optimal average heart rate (HR) and heart rate variability (HRV) for diagnostic coronary artery imaging.
• To evaluate image quality in patients undergoing high-pitch CT-angiography (CTA) with third-generation dual-source CT without beta-blocker administration.

Main Methods:

• Fifty patients underwent prospective electrocardiography (ECG)-gated, high-pitch (3.2) CT-angiography (CTA) using a third-generation dual-source 192-slice CT scanner.
• No beta-blockers were administered. Motion artifacts of coronary arteries were graded, and average HR and HRV were recorded.
• Image quality was assessed for 642 coronary segments, with interobserver agreement evaluated.

Main Results:

• Diagnostic image quality was achieved in 95% of coronary segments (86% of patients).
• Higher HR was significantly associated with non-diagnostic image quality (p=0.001).
• All patients with HR < 70 bpm had diagnostic image quality; HRV showed no significant correlation with image quality.

Conclusions:

• Third-generation dual-source CT in prospectively ECG-gated high-pitch mode enables diagnostic coronary CTA at HR up to 70 bpm.
• Heart rate below 70 bpm is a key factor for achieving diagnostic image quality in coronary CTA.
• Heart rate variability (HRV) is not a significant predictor of coronary CTA image quality.