Noninvasive radioisotope cardiographic images with digital prefiltering and boundary detection for measuring left ventricular parameters

Abstract

Noninvasive radioisotope cardiographic techniques have become a useful tool in studying left ventricular anatomy and function. The data obtainable by these techniques are often corrupted by various noise sources, and the need for image quality improvement by selective digital filtering has become evident. This investigation describes a new sequential estimating algorithm useful for several different types of radioisotope cardiographic images. In particular, the sizing of acute myocardial infarcts using technetium-99 m stannous pyrophosphate ( 99 m Tc-PYP) scintigrams and the determination of left ventricular ejection fractions using the gated blood pool method are investigated before and after the sequential estimating algorithm was applied to the original images. The results demonstrate significant improvement in myocardial infarct sizing in animals after digital filtering as well as increased accuracy in left ventricular ejection fraction determinations when compared to cineangiocardiographic measurements. The findings suggest that these nontraumatic and relatively noninvasive techniques will have improved diagnostic capability when used in conjuction with digital filtering for serial evaluation and follow-up studies of both acutely ill and nonhospitalized patients.