Radiology, Vol 146, 349-354, Copyright © 1983 by Radiological Society of North America
The application of matched filtering to x-ray exposure reduction in digital subtraction angiography: clinical results
SJ Riederer, DR Enzmann, AL Hall, NJ Pelc and WT Djang
This new digital fluorography processing method of matched filtering
generates a set of images that have been acquired at continuous video-
frame rates (30 per second) over the temporal extent of the bolus (10
seconds), and it combines them to produce the equivalent of a single
digital subtraction angiography (DSA) image. Because of the extensive
temporal averaging used, the method can provide substantial x-ray exposure
reduction per run as compared with conventional techniques for an
equivalent signal-to-noise ratio in the final image. The matched filtering
technique was compared with conventional pulsed (one per second) DSA images
of both extracranial and intracranial arteries, and the results are
presented. Matched filtered images provided image quality that was
equivalent to that of conventional DSA images at about one-fourth the
patient exposure per run for both carotid artery and cerebral vessel
studies. Despite long integration times, patient motion irretrievably
corrupted image quality in only two of five carotid artery studies and in
none of three intracranial studies. Compensation for patient motion is
demonstrated, and additional applications and limitations of the technique
are discussed.
