Patent Document ID: 4559557
Application ID: 06616206
Patent Status: 1

Claim One:
1. A digital subtraction angiography method comprising the steps of: forming a temporal subtraction image of an anatomical region and storing the digital signal values corresponding to the intensities of the picture elements (pixels) composing said image, converting said digital signal values to analog video signals for effecting display of the temporal subtraction image on a video monitor, forming a hybrid subtraction image and storing the digital signal values corresponding to the intensities of the pixels composing said hybrid subtraction image, defining in said temporal subtraction image a region or regions in which the values of the pixel signals are to be replaced by the values of the corresponding pixel signals in a corresponding region or regions, respectively, in said hybrid image, inserting the digital pixel signal values from said region or regions of said hybrid image in place of the corresponding pixel signal value in said stored temporal subtraction image, and converting the digital pixel signals representative of the resulting combined image to analog video signals for effecting display of the resulting image on the video monitor.