This Continuing Education session surveys the principles of 3D reconstruction, image quality, radiation dose, and applications of C‐arm cone‐beam CT. The availability of such systems has grown over the past several years, with applications including neurovascular and cardiovascular imaging in image‐guided interventions and surgery. Some systems employ conventional x‐ray image intensifiers, with corresponding limitations in image quality (i.e., imaging of high‐contrast structures only). More recent systems incorporating a flat‐panel detector in the imaging chain demonstrate increased field of view, higher 3D spatial resolution, improved noise characteristics, and the capability to visualize soft‐tissue structures. The basic principles of cone‐beam CT image reconstruction are reviewed (Feldkamp algorithm) in comparison to conventional fan‐beam filtered backprojection. The influence of image artifacts most relevant to C‐arm cone‐beam CT are reviewed — in particular, x‐ray scatter, object truncation, and the “cone‐beam” artifact. The factors governing 3D image quality are explained, with emphasis on the ability to image soft‐tissue structures, and issues of radiation dose characterization are discussed. The spectrum of various C‐arm cone‐beam CT systems is discussed in relation to primary applications in image‐guided interventions. Emphasis throughout is in regard to factors most relevant to the practicing medical physicists. Learning Objectives: Attendees will gain practical understanding of: 1. Basic principles of 3D cone‐beam CT reconstruction 2. Image quality and artifacts most relevant to cone‐beam CT 3. Spectrum of systems and applications of C‐arm cone‐beam CTI.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging