SIMULTANEOUS DIGITAL ICG AND FLUORESCEIN ANGIOGRAPHY

Background The simultaneous recording of indocyanine green and fluores cein angiography is since more than twenty years possible. The real-ti me digital recording of angiograms is about since 10 years possible. B ecause of the poor temporal resolution due to technical limitations, b oth of the above methods were only seldom used routinely. Graphics wor kstations can digitize and store multiple video sources real-time with full video framerate. Comparing to conventional videoangiography, the quality can be improved significantly. Materials and Methods Simultan eous ICG and Fluorescein (SIF) angiography images of a two-channel Sca nning Laser Ophthalmoscope were digitized and stored real-time at a ra te of 28-50 images/sec using a graphics workstation. The digitized ima ge sequence could be replayed as a motion picture and/or single images of the recorded sequence could be analyzed separately. Results The si multaneous digital recording of angiograms is easier, than using two v ideo tape recorders. It was possible to enhance the quality of the sto red images using standard digital image processing procedures. Morphol ogical measurements and densitometry were done with software developed for the UNIX workstation, or with personal computers using standard s oftware packages. Conclusion Simultaneous digital ICG and fluorescein angiography has several advantages over conventional video-angiographi es: the image quality is better, data retrieval is easier, it is easie r to perform than-conventional video angiography, images can be access ed trough a computer network, it is easy to perform morphological and densitometric al measurements, etc.