Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

TECHNIQUES FOR STREAK ARTIFACTS REMOVAL FROM MISSING OR TRUNCATED SPECT PROJECTION DATA

IP.com Disclosure Number: IPCOM000190291D
Publication Date: 2009-Nov-23
Document File: 6 page(s) / 87K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method for removing streak artifacts from missing or truncated Single Photon Emission Computed Tomography (SPECT) projection data is disclosed. The method comprises estimating missing data and generating quantitatively accurate artifacts free images. The method further enables reduction of cost of SPECT cameras with artifact free images.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 45% of the total text.

Page 1 of 6

RP13130

BRIEF ABSTRACT

    A method for removing streak artifacts from missing or truncated Single Photon Emission Computed Tomography (SPECT) projection data is disclosed. The method comprises estimating missing data and generating quantitatively accurate artifacts free images. The method further enables reduction of cost of SPECT cameras with artifact free images.

KEYWORDS

    Single Photon Emission Computed Tomography (SPECT), tomographic imaging, Fields-Of-View (FOV), truncated projection, artifact(s), streak artifacts, gamma rays, gamma camera, Region-Of-Interest (ROI)

DETAILED DESCRIPTION

    Single Photon Emission Computed Tomography (SPECT) is a nuclear medicine tomographic imaging technique that uses gamma rays. Although, SPECT is very similar to conventional nuclear medicine planar imaging techniques, yet it is able to provide accurate 3D data. This data is typically presented as cross-sectional slices through the patient, but can be reformatted or manipulated for other purposes.

    In the same way as an X-ray is a 2-dimensional (2-D) view of a 3-dimensional structure, the image obtained by the gamma camera is a 2-D view of 3-D distribution of a radionuclide. The SPECT imaging is performed by using a gamma camera to acquire multiple 2-D images (also called projections), from multiple angles. A computer is then used to apply a tomographic reconstruction algorithm to the multiple projections,

Page 1 of 6

TECHNIQUES FOR STREAK ARTIFACTS REMOVAL FROM MISSING OR TRUNCATED SPECT PROJECTION DATA

Page 2 of 6

RP13130

resulting in a 3-D dataset. This dataset is then manipulated to show thin slices along any chosen axis of the body, similar to those obtained from other tomographic techniques, such as Magnetic Resonance Imaging (MRI), Computed tomography (CT), and Positron emission tomography (PET).

    To acquire the SPECT images, the gamma camera is rotated around a patient. The projections are acquired at defined points during rotation, typically every 3 to 6 degrees. In most cases, a full 360 degree rotation is used to obtain an optimal reconstruction. The time taken to obtain each projection is also variable, but 15 to 20 seconds is typical. This gives a total scan time of about 15 to 20 minutes. Multi-headed gamma cameras can provide accelerated acquisition. For example, a dual headed camera can be used with heads spaced 180 degrees apart, allowing 2 projections to be acquired simultaneously, with each head requiring 180 degrees of rotation. Further, triple-headed cameras with 120 degree spacing may also be used. The SPECT can be used to complement any gamma imaging study, where a true 3D representation can be helpful, such as tumor imaging, infection (leukocyte) imaging, thyroid imaging, bone imaging, functional cardiac, and brain imaging among others. However, the projections acquired are truncated and some missing data. Rec...