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TECHNIQUES FOR NOISE REDUCTION AND RESOLUTION ENHANCEMENT IN A MULTI-SOURCE COMPUTED TOMOGRAPHY (CT) SYSTEM

IP.com Disclosure Number: IPCOM000190279D
Publication Date: 2009-Nov-23
Document File: 6 page(s) / 53K

Publishing Venue

The IP.com Prior Art Database

Abstract

A penalized post filtering technique for noise reduction and resolution enhancement in a multi-source Computed Tomography (CT) system is disclosed. The technique utilizes a convolution kernel and a penalty function. The deconvolution kernel enhances image resolution while the penalty function suppresses noise from the images to provide high quality output image.

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RP13118

TECHNIQUES FOR NOISE REDUCTION AND RESOLUTION ENHANCEMENT IN A MULTI-SOURCE COMPUTED TOMOGRAPHY (CT) SYSTEM

BRIEF ABSTRACT

    A penalized post filtering technique for noise reduction and resolution enhancement in a multi-source Computed Tomography (CT) system is disclosed. The technique utilizes a convolution kernel and a penalty function. The deconvolution kernel enhances image resolution while the penalty function suppresses noise from the images to provide high quality output image.

KEYWORDS

    Post filtering, penalized post filtering algorithm, Computed Tomography (CT), X- ray, multi-source CT system, noise, resolution, resolution enhancement, Positron Emission Tomography, iterative reconstruction, full iterative reconstruction, Contrast Noise Ratio, filters, image-domain filters, Gaussian smoothing, convolution, deconvolution, penalty function.

DETAILED DESCRIPTION

    Computed Tomography (CT) techniques are widely used for medical imaging. Generally, tomography is the technique of imaging a single plane or slice, of an object resulting in a tomogram. Computed Tomography (CT) utilizes tomography generated by computer processing. The CT techniques produce a volume of data that is processed to generate images. Such images demonstrate various body structures based on their ability to block X-ray/ Rontgen beam. The images generated by the CT are in the axial or transverse plane and orthogonal to the long axis of the body. Certain CT systems allow the volume of data to be reformatted in various planes or even as volumetric

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RP13118

three-dimensional (3D) representations of the body structures. Additionally, digital geometry processing may be utilized to generate the three-dimensional image of the inside of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation.

    Although CT systems generate images in which anatomy at the desired level remains sharp, the body structures at various other levels are blurred. Image resolution can be enhanced by varying extent and path of motion with variable depth of field and different degrees of blurring of 'out of plane' structures. One of the primary reasons for such blurring of the body structures in the images is due to noise. As such, the noise plays a crucial role in the image resolution.

    Medical experts (i.e. radiologist) desire to study and analyze every small feature in the image. This desire to study such small feature in the image leads to smaller focal spot and smaller detector pitch size in CT systems. But these smaller features are blurred by the noise introduced by various sources, such as noise associated with increasing average patient size, noise associated with desire to reduce X-ray dose, and noise associated with flux/power in a multi-source CT. Further, the noise is also introduced due to several other factors, such as system noise, environment noise among others. Therefor...