New technique for showing the relation of tomographic myocardial perfusion images obtained with thallium-201 to the coronary arteries.

Abstract

A new technique has been developed for presenting myocardial tomograms that allows the observer to perceive the shape of the thallium-201 distribution directly. The surface of the myocardium was found by applying an interactive thresholding technique to a set of conventional transverse slices. Computer graphics techniques were used to display a shaded image of that surface on a television screen, showing the three dimensional shape of the myocardial surface from any chosen aspect. A set of normal preserved coronary arteries was digitised, and using scaling and transformation techniques these arteries were mapped on to the myocardial tomograms and a shaded surface image produced with superimposed coronary arteries. This provided a familiar anatomical framework for locating perfusion defects. Its value in identifying various diseased vessels was confirmed by a comparison of the tomographic findings with the angiographic findings in five individual cases.

In Vivo CT Direct Volume Rendering: A Three-Dimensional Anatomical Description of the Heart

“…Many 3D rendering approaches exist in order to obtain a three-dimensional shape of organs, such as thresholding and surface rendering techniques which are two of the first post-processing methods used on the heart [ 23 , 24 ]; nevertheless, they presented limits in accuracy and detail, producing false positives (spurious surfaces) or false negatives (erroneous holes in surfaces), particularly in the presence of small or poorly defined features, and hindered soft tissue definition [ 13 , 25 ]. The surface reduced primarily the imaged volume to a more compact set of pre-extracted surfaces, converting the volume data into a list of polygons which represent the anatomical surface of interest; polygons representing the outside surface can be calculated using a variant of a “marching cubes” algorithm [ 26 ].…”

Polar Presentation of Coronary Angiography and Thallium-201 Single Photon Emission Computed Tomography

“…Selective 36·898086 coronary angiography describes individual coronary artery anatomy and gives accurate information of the localization and severity of coronary artery disease. Various methods have been used to compare coronary angiographic and myocardial scintigraphic findings (7,13,14,21,22,25,29).…”

“…et coli (13). constructed a three-dimensional presentation method of 201Tl SPECT using the average positions of the major coronary arteries in some different patterns.…”