Coronary artery imaging with contrast-enhanced MDCT: extracardiac findings

The purpose of our study was to evaluate the incidence of extracardiac findings on contrast-enhanced MDCT of the coronary arteries and to assess the effect of different field-of-view settings.

Patients with suspected coronary artery disease (n = 166) were examined with contrast-enhanced MDCT (16 x 0.75 mm focused on the heart) during injection of contrast material (80 mL injected at a rate of 4 mL/sec) followed by saline (20 mL injected at 4 mL/sec). Retrospectively gated images were reconstructed at a 1-mm slice thickness and a 0.5-mm increment with isotropic voxels of 1 mm3. Images were reviewed for extracardiac findings, which were then classified as none, minor, or major with respect to their impact on patient management and treatment. In a different group of patients (n = 20), chest scans (16 x 1.5 mm) were used for measuring volumes of displayed body structures on wholechest scans, coronary artery MDCT images, and coronary artery MDCT images reconstructed with the maximum field of view.

Extracardiac findings were detected in 41 patients (24.7%). Findings were classified as minor (19.9%) or major (4.8%). Among the major findings, which had an immediate impact on patient management and treatment, were bronchial carcinoma and pulmonary emboli. Volume analysis revealed that 35.5% of the total chest volume was displayed on dedicated coronary artery MDCT focused on the heart, whereas 70.3% of the chest was visible when coronary artery MDCT raw data were reconstructed with the maximal field of view (p < 0.001).

Coronary artery MDCT can reveal important findings and disease in extracardiac structures. Thus, the entire examination should be reconstructed with the maximum field of view and should be reviewed by a qualified radiologist.