- Bone-Subtracted Spinal CT Angiography Using Nonrigid Registration for Better Visualization of Arterial Feeders in Spinal Arteriovenous Fistulas
CTA images of the arterial and late arterial phases were used to obtain warped images of the late arterial phase by nonrigid registration that was adjusted to the arterial phase images. R-CTA images were then obtained by subtracting the warped images from the arterial phase images. R-CTA had a higher accuracy compared with conventional spinal CTA (80% versus 47%). The authors conclude that subtracted CTA imaging using nonrigid registration detects feeders of spinal arteriovenous fistulas more accurately and quickly than conventional CTA.
- CT Metal Artifact Reduction in the Spine: Can an Iterative Reconstruction Technique Improve Visualization?
CT images were reconstructed by using weighted filtered back-projection and iterative metal artifact reduction. Two neuroradiologists evaluated images in the region of spinal hardware and assigned a score for the visualization of critical anatomic structures by using soft-tissue and bone windows. Using bone windows, they measured the length of the most pronounced linear artifacts. Visualization of critical soft-tissue anatomic structures was significantly improved by using iterative metal artifact reduction, but there was not a significant improvement in visualization of critical osseous structures. Routine generation of these iterative reconstructed images in addition to routine weighted filtered back-projection is recommended.