A computer processing system for ECG-gated radioisotope angiography of the human heart

A comparison of simultaneous measurements of systolic function in the baboon by electromagnetic flowmeter and high frame rate ECG-gated blood pool scintigraphy.

“…To reduce the amount of analog flowmeter data to manageable proportions, and yet retain the ability to observe systematic changes in LV function, five consecutive flow profiles acquired during the first 5 minutes of data collection and five profiles from the last 5 The magnetic tape record of the scintigraphic portion of the study was analyzed with a large-scale computer system using a previously described technique. 5 The scintillation data were organized into a high temporal resolution (10 msec/frame = 100 frames/sec) image sequence representing a single, average cardiac cycle.…”

“…5 The scintillation data were organized into a high temporal resolution (10 msec/frame = 100 frames/sec) image sequence representing a single, average cardiac cycle. Each image in the sequence contained 4096 picture elements (64 X 64).…”

Assessment of Ventricular Function by Radionuclide Angiography: Applications and Results

“…In or der to maximize the information content available for analysis of each point on the time-volume curve, the computer can super impose the corresponding images from suc cessive cardiac cycles, determining the ap propriate points of superimposition by refer ence to a gating signal, usually supplied by an electrocardiographic impulse [47], Two approaches to radionuclide cinean giography are available. Either a single bolus of isotope can be followed in its passage through the heart ('first pass method') [3,12,48,49] or the isotope can be allowed to equil- ibrate within the intravascular compartment prior to imaging ('equilibrium method') [1, [43][44][45][46]. Much controversy has been engen dered during the past 7 years regarding the relative merits of the two approaches.…”

“…To follow the movement of blood into and out of the cardiac chambers during the cardiac cycle, images of finite du ration are obtained rapidly and sequentially during the cardiac cycle. The temporal dura tion of each image and, thus, the number of images obtained per cardiac cycle is directly determined by settings on a computer, which can digitize and store the quantitative infor mation regarding the number of gamma photons incident on the detector at any one location at any given time [1, [43][44][45][46], This digitized information can be displayed graph ically by the computer. Rapid sequential dis play of all images is.…”

“…Nonetheless, to minimize diffi culties in visual interpretation of regional function, the nongeometric, count-based ra dionuclide angiographic method has been employed for quantitative assessment of re gional function. Several simple (stroke vol ume map [1, 45,46], ejection fraction map [73]) and more complex (Fourier transform contour maps [74][75][76]) methods have been developed for such purposes. However, while the authors of these methods have found them to be valuable in certain types of analy ses, objective, count-based assessment of re gional function has not as yet supplanted visual assessment by the trained observer as the primary modality for detecting regional dysfunction.…”