An angiogram is a study of blood vessels where an angiographic chemical contrast agent is injected while a sequence of images (typically x-rays) are obtained. The contrast pattern on the sequence of images provides information about the vascular anatomy and physiology. The discovery that contrast in blood vessels varies at cardiac frequency in magnitude and phase, which may be visualized as a spatiotemporal reconstruction of cardiac frequency angiographic phenomena, enables a set of processes for increasing the signal to noise ratio or equivalently the informational content of an angiogram. In this invention, the organization of cardiac frequency magnitude and phase enables equivalent information on anatomy and physiology to be obtained with less dose of injected chemical contrast agent, less x-ray dose, and/or less navigation of the injecting catheter within blood vessels. The cardiac frequency magnitude and phase is organized so that the arterial and venous subsystems of circulation have coherence at cardiac frequency. This enables processes for diagnosing deficits of circulation that involve alterations in the transit of blood from the arterial to the venous subsystems of circulation. Furthermore, the discovery of cardiac frequency magnitude and phase organization enables the design and manufacture of lighter and more portable angiography equipment.
