Sources of Apical Defects on a High-Sensitivity Cardiac Camera: Experiences from a Practice Performance Assessment

Abstract

Apical perfusion artifacts seen on a high-sensitivity camera warranted a practice performance assessment to evaluate contributions from soft-tissue attenuation, patient positioning, and image processing techniques. Methods: Cardiac perfusion studies (n = 534) spanning 5 mo were retrospectively reviewed. Images were acquired with the patient in the upright position, and attenuation correction was used. Regression analysis and contingency tables correlated clinical data to the presence of apical artifacts. Results: There was a positive correlation of with female sex (χ² = 32, P < 0.001), degree of overlying soft tissues (χ² = 20, P < 0.002), and breast cleavage (χ² = 7, P < 0.008) and a negative correlation with angiography-confirmed disease (χ² = 6, P < 0.02). There was moderate interobserver agreement between 2 observers in determining the presence of apical defects (κ= 0.44, 95% confidence interval = 0.19–0.69), and there was a perceived improvement of apical defects using fewer iterative updates (χ² = 8, P < 0.003). Conclusion: An understanding of sources contributing to imaging artifacts is a crucial portion of quality assessment in radiology and nuclear medicine. A practice performance assessment study at our institution showed that apical artifacts on a new-generation cardiac camera can be partially attributed to overlying soft-tissue attenuation and ameliorated by altering the reconstruction.