Cardiac Mensuration by the Cardiac Volume Method

The cardiac volume determination as an accurate method of cardiac mensuration has been used widely in Scandinavia for many years but has not gained wide acceptance in this country. This has probably resulted from difficulties in utilizing the reported data, largely in the Scandinavian and German literature. Correction factors applying to target-film distances are different from those used in America, expression of reference data is in the metric system, and lastly it is difficult to find complete source data for normal standards for children and adults. Hanson (5) in 1961 advocated wider use of the cardiac volume determinations in America but failed to provide correction factors of the 40-inch target-film distance often used in pediatric roentgenology. He also referred the interested reader to original sources for necessary calculations and normal standards. Our review of this literature was fraught with sufficient difficulty in extracting necessary data that in this report we have attempted to present in one source all the data required to institute the method for children and adults. In addition, data have been modified for incorporation of patient dimensions without prior conversion to the metric system. Historical Review Rohrer (15), in 1917, reported a method for radiologic heart volume determination utilizing an orthodiagraphic technic. This method was based on his assumption, from 3-dimensional geometry, that the volume of any body may be determined from its dimensions in two projections. He assumed the heart to be a paraboloid and derived a formula for calculation of its volume that consists of the product of the orthodiagraphically traced frontal cardiac area, the lateral cardiac diameter, and a constant K. A similar formula was arrived at independently by Kahlstorf in 1932 (7). Jonsell (6) revised and improved upon this method, basing his calculations on routine roentgenograms rather than orthodiagraphy. Since that time, the method has been further expanded by the introduction of more exact values for K at various focal-film distances and exploration of correlations of the method with such physical variables as sex, height, weight, surface area, blood volume, physical capacity for work, as well as volume measurements in normal and pathologic states (1, 2, 8–10, 12, 14). The method was also extended to infants and children (4, 11). Kjellberg et al. (9) have shown that there is a decrease in heart volume after birth, reaching a minimum on the fourth day of life. A 25 per cent reduction is the average loss. Method Calculation of cardiac volume utilizes postero-anterior and lateral roentgenograms. Three measurements are taken in centimeters (Fig. 1). The length diameter (L) is measured from the junction of the superior vena cava and right atrium to the cardiac apex.