Dual-energy digital subtraction angiography using characteristic radiation and K-edge filtration

Dual-Energy Digital-Subtraction Angiography (DEDSA) is an improved technique for visualizing contrast-filled structures that could be applied in all cases where contrast imaging is currently used and which would allow for improved visualization with lower iodine doses. In this work, DEDSA images have been acquired of phantom subjects using a patented K/sub /spl alpha// X-ray source that relies on novel anode coatings and k-edge filters to enhance the sensitivity to iodine while removing tissue and bone features from the image. It has been demonstrated that concentrations as small as 2.8 mg/cm/sup 2/ within 12.5 cm tissue equivalent can be detected (SNR=1) with essentially perfect cancellation of tissue and bone artifacts. Such a system would be of great use for obtaining subtracted arteriograms and for visualizing arterial stents and balloons in the heart and elsewhere in the body. Since the images are acquired at high speed, artifacts due to tissue motion can be entirely avoided. Patient dose requirements are similar to that used for present-day procedures.