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COMPUTED TOMOGRAPHY COMPOUNDING FOR CREATING ATTENUATION

IP.com Disclosure Number: IPCOM000250596D
Publication Date: 2017-Aug-07
Document File: 4 page(s) / 3M

Publishing Venue

The IP.com Prior Art Database

Abstract

A technique for creating attenuation templates using compound computed tomography (CT) is disclosed. The technique is used in reconstruction of positron emission tomography (PET) and magnetic resonance (MR). Based on the fact that star artifacts are generally orthogonal to the scanner axis. A new CT dataset with relatively less artifacts is obtained by compounding multiple CT acquisitions of the same object acquired at different positions.

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COMPUTED TOMOGRAPHY COMPOUNDING FOR CREATING ATTENUATION TEMPLATES

BACKGROUND

 

The present disclosure relates generally to attenuation correction in radiology and more particularly to compounding of computed tomography for creating attenuation templates.

Attenuation correction is one of the main determining factors for quantitative accuracy of positron emission tomography (PET) and magnetic resonance (MR) data. The attenuation caused by the patients is addressed by solutions based on the segmentation of MR data. However, attenuation caused by hardware elements in the field of view is addressed by using stored templates of the elements such as phantoms, receive coils and more.

Typically, the attenuation template of any given piece of hardware is created by acquiring a CT scan. Further, the data is processed to account for the energy difference between CT and PET. Hence, the data is then resampled to the desired orientation and resolution.

Furthermore, the acquired CT data is mostly affected by star artifacts caused by high density elements present in the hardware such as electronic components and cables. Therefore, uncorrected artifacts lead to inaccurate attenuation map and causes biased reconstructed PET emission, as depicted in figure 1.

Figure 1

Industrial CT scanners are capable of acquiring virtually artifact-free images of perfect resolution. However, due to practical reasons clinically available CT scanners are preferred. Other approaches such as artifact reduction technique and iterative reconstruction methods were developed to alleviate star artifacts to minimum. Both the technologies causes the loss of data due to high density elements in the field of view

It would be desirable to have an efficient technique for creating attenuation templates to overcome the artifacts.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 depicts an uncorrected artifacts leading to inaccurate attenuation map and causing biased reconstructed PET emission.

Figure 2 depicts a fact that star-artifacts are generally orthogonal to the scanner axis.

Figure 3 depicts a resulting CT with reduced artifact used to generate an attenuation template

DETAILED DESCRIPTION

A technique for creating attenuation templates using compound computed tomography (CT) is disclosed. The technique is used in reconstruction of positron emission tomography (PET) and magnetic resonance (MR). Based on the fact that star artifacts are generally orthogonal to the scanner axis. A new CT dataset with relatively less artifacts is obtained by compounding multiple CT acquisitions of the same object acquired at different positions, as depicted in figure 2.

Figure 2

Spatial compounding is a processin...