METAL ARTIFACT REDUCTION FOR 3D-DIGTIAL SUBTRACTION ANGIOGRAPHY

摘要

A computed tomography (CT) imaging apparatus that reduces metal artifacts for digital subtraction angiography by, in circuitry, obtaining mask frames and contrast frames generated during scans of an object; performing a first reconstruction of the mask frames to generate metal volume data; identifying metal voxels in the metal volume data; re-projecting the metal voxels into the mask frames to generate metal-mask frames; defining a region of interest in each of the mask frames, each region of interest including metal regions; re-projecting the contrast frames; blending the mask frames with the re-projected contrast frames; registering the contrast frames with respect to the blended mask frames performing a cross-correlation analysis of the mask frames and the contrast frames, frame-pair-by-frame-pair; subtracting the registered contrast image from the corresponding mask image, frame-pair-by-frame-pair, to generate subtracted frames; and performing a second reconstruction on the subtracted frames.