Coronary Artery Imaging with Contrast-Enhanced MDCT: Extracardiac Findings
Haller S, Kaiser C, Buser P, Bongartz G, Bremerich J.
OBJECTIVE: 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.
SUBJECTS AND METHODS: 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 whole-chest scans, coronary artery MDCT images, and coronary artery MDCT images reconstructed with the maximum field of view.
RESULTS: 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).
CONCLUSION: 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.