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A METHOD FOR DETERMINING OPTIMAL NUMBER OF GATES FOR GATED NUCLEAR MEDICINE ACQUISITIONS

IP.com Disclosure Number: IPCOM000195161D
Publication Date: 2010-Apr-22
Document File: 5 page(s) / 41K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method for determining optimal number of output gates in a gated acquisition for multi-gate image visualization, inter-gate image registration and improved image quality in motion corrected nuclear medicine images is disclosed. In this method, over-gated datasets are reconstructed using either analytic methods or iterative methods that are focused on a region of interest (ROI), such as a lung tumor or the heart. These gated datasets are then combined one-by-one into longer gates in either sinogram domain (which requires additional reconstructions) or in image domain as long as the addition of the new gate results in a small entity. Using such method, an optimal number of gates and a gating scheme are invented such that each final gate will have negligible motion.

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RP13116

A METHOD FOR DETERMINING OPTIMAL NUMBER OF GATES FOR GATED NUCLEAR MEDICINE ACQUISITIONS

BRIEF ABSTRACT

    A method for determining optimal number of output gates in a gated acquisition for multi-gate image visualization, inter-gate image registration and improved image quality in motion corrected nuclear medicine images is disclosed. In this method, over- gated datasets are reconstructed using either analytic methods or iterative methods that are focused on a region of interest (ROI), such as a lung tumor or the heart. These gated datasets are then combined one-by-one into longer gates in either sinogram domain (which requires additional reconstructions) or in image domain as long as the addition of the new gate results in a small entity. Using such method, an optimal number of gates and a gating scheme are invented such that each final gate will have negligible motion.

KEYWORDS

    Gate(s), Gated Nuclear, gating, Nuclear Imaging, Nuclear Medicine Acquisition,motion, Motion Correction, reconstruct, Region of Interest (ROI), Positron Emission Tomography (PET), Single-Photon Computed Tomography (SPECT), Computed tomography (CT).

DETAILED DESCRIPTION

    Medical imaging refers to various techniques and processes, which are used to create images of the human body (or its parts thereof) for various clinical purposes, such as diagnosis, examination of diseases or study of normal anatomy, physiology. While nuclear medicine is a subdivision of the medical imaging that uses radioactive isotopes (radionuclide) in the diagnosis and treatment of various diseases.

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RP13116

    There exist various gating techniques in the field of the medical imaging for diagnosis and/or examination. However, such gating techniques may utilize large number of gates for processing of the images and hence are "over-gated". The image from each of such gates creates noise and requires processing of unnecessarily high number of reconstructions. Furthermore, when non-linear image reconstruction algorithms are used, post-reconstruction combination of the images from the low count gates can be very different and have poor quality as compared to the reconstruction of a single gate with a good number of counts. On the other hand, if few gates are used ("under-gating"), then motion artifacts remain in those gates.

    Figure 1 illustrates a flow diagram for the proposed method for determining the optimal number of gates for gated nuclear medicine acquisitions. At step 104, data is divided into a large number of gates (e.g. 40-50 for respiratory gating). At step 106, each image is reconstructed using a rapid reconstruction technique. The rapid reconstruction technique can either be an analytic method (such as Filtered Back- Projection (FBP)) or an iterative method, (such as keyhole reconstruction) focused on the region of interest (ROI). At step 108, dimension or size of the object of interest (e.g. tumor volume, left ventricle volume) inside the reconstructe...