Cardiac computed tomographic angiography: evaluation of non-cardiac structures

Cardiac computed tomography is a promising new technology for non-invasive evaluation of the coronary arteries. As CT is inherently a high resolution volumetric imaging modality, data from structures other than the heart can be accessed in studies performed primarily for cardiac indications. Current generation scanners can easily detect abnormalities such as pulmonary emboli and aortic dissection on routine coronary CT angiograms. Many other abnormalities such as small pulmonary nodules can also be detected. While major abnormalities like aortic dissection are of obvious clinical importance, detection of incidental abnormalities such as small pulmonary nodules less than 4 mm in diameter has not yet been shown to positively affect patient outcomes, and may lead to unnecessary testing. Recommendations for image reconstruction and training in interpretation of incidental findings continue to evolve, but most agree that coronary CT angiography should be focused primarily on the coronary arteries.