Gated cardiac imaging using a continuously rotating CT scanner: clinical evaluation of 91 patients.

To produce electrocardiographically (ECG)-gated computed tomographic (CT) images of the heart, a post-data-acquisition ECG correlation technique was used in which data for missing angular projections are derived from the original scan data to complete 360 angular projections. Improved image quality and clinical usefulness were demonstrated compared with routine nongated CT and two-dimensional echocardiography. Gated CT was better than nongated CT in 26 of 41 positive and three of five negative cases of suspected myocardial infarction, four of 10 positive and one of 12 negative cases of suspected left atrial mass, three of 10 cases with pericardial fluid collection, and three other cases. Compared with echocardiography, CT was of additional value in eight of 10 cases of myocardial infarction, five of nine positive and one of 10 negative cases of suspected left atrial mass, four of 10 positive and one of three negative cases of suspected pericardial fluid collection, and two other cases. The equipment required for CT gating is of low cost, but the examination time is lengthy and less conveniently performed than echocardiography. However, when echocardiography is indecisive or suspected to be falsely negative, gated CT imaging of the heart is recommended.