[Comparison of clinical methods for the demonstration of radiation-induced lung changes. Experimental study on...

The purpose of this study was to compare the value of different imaging methods (radiography, computer tomography and scintigraphy) for demonstrating pulmonary fibrosis or radiation pneumonitis. The right lungs of 50 rabbits were irradiated with 3200 to 6200 rd. The lung changes were observed by the above methods over a period of 13 weeks. Histological examination served as the basis for evaluating the imaging methods. The comparison demonstrated the superiority of computer tomography when density measurements were included in the diagnostic criteria. The accuracy was about 95%. Scintigraphy was inferior to computer tomography as a quantitative method, using differences in the counts per unit area. Radiology as a subjective method achieved an accuracy of about 84%, approximately the same as scintigraphy.