Motion artifacts on coronary CT angiography images in patients with a pericardial effusion.

Background: Patients with a pericardial effusion can have a pendulum-like movement of the heart. No reports associate the presence of pericardial fluid with coronary CT angiography (CTA) images that are degraded by motion artifact.

Objective: We tested the hypothesis that patients with pericardial effusion have coronary CTA images compromised by motion artifacts, even when other known causes of motion artifact in coronary imaging are minimized.

Methods: Among the prospectively electrocardiogram-gated single heart beat 320-detector row coronary CTA studies performed from September 2009 to May 2013, 13 consecutive studies acquired with a heart rate <60 beats/min that indicate a pericardial effusion formed an effusion cohort. A control cohort included 13 studies with no pericardial fluid performed by the same CT scanner; these were pair-matched to the effusion cohort for heart rate, sex, age, and body mass index. All studies were free of arrhythmia and respiratory motion. Motion artifact was separately assessed (3-point scale) at 8 coronary segments by 2 cardiovascular imaging teams.

Results: The mean pericardial effusion volume for the effusion cohort was 129 ± 57 mL (range, 39-222 mL). Intra-observer/interobserver reproducibility of the motion artifact scores were good (κ = 0.636-0.791). Motion artifacts were more frequently observed in the effusion cohort for the left circumflex (no, mild, severe artifact, 54%, 46%, 0% vs. 81%, 19%, 0%, respectively, for effusion vs. control; P = .039) and right coronary arteries (no, mild, severe artifact = 41%, 44% 15% vs. 79%, 21%, 0%, respectively, for effusion vs control; P < .001), especially for the middle or distal segments. Larger effusion volumes were associated with more severe motion artifacts.

Conclusion: Patients with pericardial effusion have coronary CTA images compromised by cardiac motion artifacts, particularly in the left circumflex and right coronary arteries.