Radiologic heart volume from 100 mm photofluorograms.

Radiologic heart volume could be calculated in 1 188 (94%) of a sample of 1 263 male civil servants over the age of 40. The chest films were taken under the conditions of massminiture radiography with no subject preparation and an unmodified Odelca 100 mm unit. Estimates of observer variability are reported an 'normal values' for a free-living population given. A method of calculating a correction factor for image magnification and subsequent reduction in size is described, and evidence presented that each Odelca unit has a unique correction factor.