Reduction of metal artefacts from bilateral hip prostheses during lower extremity computed tomography angiography: an experimental phantom study.

Introduction: Image quality reduction due to metallic artefacts is a significant challenge during vascular computed tomography (CT) imaging of the lower extremities in patients with hip prostheses. This study aims to analyse various reconstruction algorithms' ability to reduce metal artefacts due to two types of hip prostheses during lower extremity CT angiography examinations.

Methods: A pelvis phantom was fabricated with the insertion of a tube filled with contrast media to simulate the femoral artery, and the phantom was then CT scanned with and without hip prostheses.

Identification of reflected, scaled, translated, and rotated objects from their radon projections.

In this paper, we present a method for identification of binary objects from a given set of radon projections. Given a suitably regular 2-D function f, we form a new function g from f by using the operations of reflection, scaling, translation, and rotation. We show how the radon projections of g are related to those of f and devise a procedure that can be used to determine the parameters from the radon projections of f and g.