Automatic construction of pulmonary functional images.

Dynamic study of regional ventilation of Xenon-133 with a gamma camera requires the medical interpretation of many analog scintigraphic images and time-consuming curve analysis. We have developed a program for the immediate creation of two functionally digitalized images by minicomputer which collects the data from the whole study. These images are constructed by assigning a value to each pont which depends upon the dynamic phenomenon. The program automatically computes the working files of the dynamic acquisition, performs the background subtraction, and delineates the boundaries of the lungs using isoactivity lines. Then the functional images of transit time and clearance of the radioactive gas in the alveoli are reconstructed. This processing takes less than 1 min and allows both time sharing and enhancement of interpretation.