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CONE-BEAM COMPUTED TOMOGRAPHY RECONSTRUCTION ALGORITHM

IP.com Disclosure Number: IPCOM000208681D
Publication Date: 2011-Jul-15
Document File: 9 page(s) / 283K

Publishing Venue

The IP.com Prior Art Database

Abstract

A technique to perform image reconstruction from a single axial conebeam Computed Tomography (CT) full-scan is disclosed. Accordingly, an axial cone-beam CT reconstruction algorithm is developed. The proposed technique is particularly beneficial for cardiac scans. Further, the proposed technique provides a good temporal resolution and reduces cone-beam artifacts.

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RP13607

CONE-BEAM COMPUTED TOMOGRAPHY RECONSTRUCTION ALGORITHM

BRIEF ABSTRACT

    A technique to perform image reconstruction from a single axial cone- beam Computed Tomography (CT) full-scan is disclosed. Accordingly, an axial cone-beam CT reconstruction algorithm is developed. The proposed technique is particularly beneficial for cardiac scans. Further, the proposed technique provides a good temporal resolution and reduces cone-beam artifacts.

KEYWORDS

    Axial, Cone, Beam, CT, Reconstruction, Algorithm, Half-Scan, Full-Scan, Cardiac, Temporal, Resolution, Artifact

DETAILED DESCRIPTION

    Typically a tomography application comprises a source that emits beams from the object, which are collected by a detector. Beams are emitted with a scanning geometry comprising parallel beams, circular trajectory beams, divergent beams, circular trajectory beams, cone beams or helical trajectory beams.

    In a system comprising transmission computed tomography, a source projects a beam with scanning geometry that passes through the object, and transmits upon an array of detectors. The intensity of the transmitted radiation is dependent upon the attenuation of the object.

    In another conventional technique, in which a system comprising emission computed tomography is utilized, the distribution of radio-isotopes within an

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RP13607

object is transmitted upon an array of detectors. The detectors produce projection data, which is a separate electrical signal resulting from scanning geometry. Further, the projection data is sent to a computer for processing. The computer processes the data based on the mathematical procedure called tomographic reconstruction. The tomographic reconstruction includes algorithms that manipulate the projection data to produce the image.

    Conventionally many different reconstruction algorithms exist. Most such reconstruction algorithms fall into one of two categories: Filtered Back Projection (FBP) and Iterative Reconstruction (IR). Usually, these algorithms provide inexact results and represent a compromise between accuracy and computational time required. FBP demands fewer computational resources, while IR generally produces fewer artifacts. Artifacts are errors that result from the reconstruction. FBP includes analytical methods involving Fourier transform. IR includes algebraic methods and probabilistic methods.

    Algorithms used in limited data tomography results in errors, or artifacts within the reconstructed image. Limited angle data tomography typically causes "fan-shape" or "butterfly" artifacts within the reconstructed image. Sparse projection data tomography typically causes "star-pattern" artifacts within the reconstructed image. Many algorithms have been proposed for limited data tomography including Fourier methods, sinogram methods, regularization methods, Bayesian method or wavelet techniques. The algorithms are vulnerable to artifacts, unless a "reference image" is used, which is not always available.

    Henc...