Rapid Sequential Visualization of the Heart and Great Vessels in Man Using the Wide-Field Anger Scintillation Camera

Abstract

The recent development of the instantaneously sensing Anger scintillation camera, capable of recording wide-field radioisotope images from the precordium, and a system for video storage and analysis has provided a means of visualizing the anatomic and hemodynamic features of the heart and great vessels without the hazards involved in introducing a radiopaque agent. Sodium pertechnetate (^99mTcO_4^-) produces no cardiocirculatory effects or untoward actions and delivers only 0.13 rads of total body radiation. Following injection, the rapidly changing distribution of radioactivity within the heart is recorded by the scintillation camera-television system which includes no inherent dead time or overlap of the scanned field from frame to frame. Video tape replay is available immediately and sequential integrated pictures are possible at any rate up to 60 sec. Radioisotope images of longer intervals are easily obtained by the integration of successive stop-action fields reproduced on a high resolution television monitor and photographed on rapidly developed film. In addition, the replay may be gated and tracked, allowing selected phases to be integrated and time-concentration curves of blood flow. Five to 10 millicuries of ^99mTcO_4^- in 2 to 8 cc were rapidly injected into selected cardiac chambers at the time of diagnostic catheterization in 50 patients with a variety of congenital and acquired forms of heart disease. Movement of radioisotope closely reflected the hemodynamic alterations caused by these conditions, as determined by standard contrast angiocardiography. The radioisotope-angiocardiogram provides a new approach for visualization of the cardiovascular system, does not require the use of radiopaque medium, is safer than angiography, and does not disturb circulatory function.