Computerized system for the measurement of gallstone volume, in vivo

Instrumentation and methodology for the determination of gallstone volume from standard roentgenographic views have been developed. Evaluation of size is made by using video viewing, an operator-set electronic window, intercept registers, and the programming of a PDP/8E for handling the data. The programming makes corrections for geometric factors arising from anatomical variations, corrections for variations in technique, roentgenographic magnification, and provides for the use of several roentgenographic views. The precision of the measuring (video) technique is approximately 0.5 mm as measured on the roentgenogram. Estimates and test data indicate that this system should be capable of an absolute accuracy within 10% of the true volume.