Precision subtraction computed tomographic angiography
View Patent ↗This invention relates to a novel technique for producing images of arteries that overcomes a significant limitation of conventional computed tomographic angiography (CTA). The technique is performed by the acquisition of pre-contrast computed tomography in addition to the conventional computed tomographic angiography and by the digital subtraction of the pre-contrast computed tomogram from the conventional CTA after alignment of the two images.
1. A method for the suppression of calcification in computed tomographic angigraphy (CTA) which comprises:
a. performing a pre-contrast computed tomogram (pcCT);
b. performing a CTA; and
c. computing a digital subtraction computed tomographic angiogram (sCTA) by:
i. interpolating the pcCT and the CTA by a factor of two in all directions using the windowed sinc method;
ii. segmenting the bone in the interpolated pcCT;
iii. registering each calcification region in the segmented pcCT to the interpolated CTA with piecewise rigid transformation; and
iv. subtracting the registered calcification region from the interpolated CTA; and
d. displaying the sCTA.