A New Washout Rate Display Method for Detection of Endocardial and Pericardial Abnormalities Using Thallium-201 SPECT

Abstract

Using thallium-201 single-photon emission computed tomography images, we have developed a new washout rate display method, which can demonstrate abnormalities in the inner and outer sections of myocardial slices. The washout rate is calculated on a pixel basis: the count of a pixel in an early slice is compared with the mean count of a set of pixels in the corresponding slice of the delayed images. The output of this method is a set of 10 images showing the washout rate for Slices 1 to 10 of the left ventricle. A low washout rate can be visualized in detail on both the inner and outer parts of the slices. We have applied this method on several patients who had a non-Q-wave infarction and compared these results with those of the bull’s-eye method. Our method was able to distinguish the location of abnormalities in the endocardial and pericardial parts of myocardial slices. The shape and the color of the output images provide information that is helpful in the diagnosis of non-Q-wave infarction.