A Method for the Quantitative Roentgenological Determination of the Amount of Calcium Salts in Bone Tissue:Its Use in the Study of Calcium Reduction in the Phalanges of the Fingers in Chronic Polyarthritis
By means of photographing simultaneously on the radiogram a reference system in the form of a series of aluminium step-wedges, it is possible to calculate the absorption in the different parts of the bone, expressed in units of the reference system. The sources of error in this method are: unevenness of roentgen intensity over the whole film, defective film emulsion, lack of uniform developing conditions over the entire film. The method was used to study the degree of reduction of Ca salts in patients with chronic polyarthritis. The figures obtained are compared with the clinical picture. In the clinically advanced cases a good correlation was found between the degree of reduction of the Ca salts and the severity of the disease. The method described appears to be suitable for the study of a number of problems in quantitative roentgen diagnosis.