Radiology of the Heart and Great Vessels

The methods used in .r-ray examination of the heart and great vessels of the thorax include fluoroscopy and radiography, measurement of the cardiac diameters, and special observations after a ' barium swallow \ Owing to the divergence of the rays from the anode of the x-ray tube, there is much distortion of the image if the tube is close to the chest; so, to get an accurate representation of the size of the heart, films should be taken at a distance of six feet, or the actual size of the heart may be mapped out on the screen by cutting down the diaphragm to give an image of the heart border on the screen about the size of a postage stamp, thus using the central ray to delineate the outline of the heart shadow. Other procedures such as cinematography and kymographic analysis of the heart movements have not reached such a stage of perfection