Volumetric Measurement of Heart Using PA and Lateral View of Chest Radiograph

Abstract

Heart size is of fundamental importance in diagnosis and radiography is a reliable method of estimating size. Volume of the heart is computed by cardiac measurements in postero-anterior (PA) and lateral view of chest radiograph Determination of heart size is a major factor in the clinical evaluation of the healthy or failing heart. In this paper, we describe an automatic method for computing the approximate volume of the heart based on cardiac rectangle. The cardiac rectangle varies in size depending on the heart size. The chief measurement is made on the PA view. The measurement is also made in true lateral view. The first step in computer processing was to extract size, contour and shape of the heart from the standard PA and lateral chest radiograph using fuzzy c-means. An algorithm that constructs a cardiac rectangle around the heart is developed. The extent of rectangle is found from features present in horizontal and vertical profiles of the chest X ray. Once cardiac outline is obtained it is straightforward to obtain measurements characterizing the shape of the heart. Volume of the heart is computed from various features obtained from pa and lateral chest radiograph. The measurements have proved of most value in estimating alteration in size of the heart shadow due to physiological or toxic causes.