Photon scatter imaging
Inventors
Hugg, James William • Radley, Ian
Assignees
Publication Number
US-10534096-B1
Publication Date
2020-01-14
Expiration Date
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Abstract
One embodiment provides a method, including: receiving a dataset associated with a plurality of photon emission events interacting with a detector array of an imaging device; identifying a first subset of the dataset associated with a plurality of unscattered photon emission events from the plurality of photon emission events; identifying a second subset of the dataset associated with at least one scattered photon event from the plurality of photon emission events; determining, for a scattered photon event, a likely location of emission of the scattered photon event using data from the first subset of the dataset associated with the plurality of unscattered photon events; and correcting the dataset by associating the scattered photon event with the determined likely location of emission. Other aspects are described and claimed.
Core Innovation
One embodiment provides a method comprising: receiving a dataset associated with a plurality of photon emission events interacting with a detector array of an imaging device; identifying a first subset of the dataset associated with a plurality of unscattered photon emission events; identifying a second subset of the dataset associated with at least one scattered photon event; determining, for a scattered photon event, a likely location of emission of the scattered photon event using data from the first subset of the dataset associated with the plurality of unscattered photon events; and correcting the dataset by associating the scattered photon event with the determined likely location of emission.
The background describes a problem of loss of signal due to Compton scattering of emission photons in the body of the patient during imaging, where scattered counts may be included in the image producing a blurring effect, and that an estimate of the scatter component of the image can be up to 60% of the image counts in human patients, leading to a requirement that a patient must be given a higher dose of a radioactive tracer because a significant fraction of detected photon emission events will be discarded as scatter during image reconstruction.
Accordingly, an embodiment provides a system and method of correcting an image by associating at least one scattered photon event with the location of a plurality of unscattered photon events, and the system can identify a scattered photon emission event by its energy, which determines a range of Compton scattering angles, thereby providing a system and method for reconstructing images using the scattered photon emission events rather than discarding them as unwanted image noise.
Claims Coverage
The patent contains three independent claims and three corresponding inventive features covering a method, an information handling device, and a product storing code.
Receive dataset of photon emission events with spatial position and energy identified using single photon emission computed tomography
Receiving a dataset associated with a plurality of photon emission events interacting with a detector array of an imaging device, wherein the dataset contains at least one characteristic of each of the plurality of photon emission events including a spatial position and an energy identified using single photon emission computed tomography; identifying a first subset associated with unscattered photon emission events; identifying a second subset associated with at least one scattered photon event by estimating a scatter fraction in the photopeak energy window for each pixel; determining, for a scattered photon event, a likely location of emission using data from the first subset based upon the at least one characteristic; correcting the dataset by associating the scattered photon event with the determined likely location; and providing an image generated from the corrected dataset.
Information handling device configured to perform dataset identification and scatter association
A processor and memory device that stores instructions executable to: receive a dataset associated with photon emission events interacting with a detector array; identify a first subset of unscattered events and a second subset of scattered events by estimating a scatter fraction in the photopeak energy window for each pixel; determine for a scattered photon event a likely location of emission using data from the first subset based upon the at least one characteristic; correct the dataset by associating the scattered photon event with the determined likely location; and provide an image generated from the corrected dataset.
Product storing code to identify scatter and associate scattered events with likely emission locations
A storage device that stores code executable by a processor comprising code that receives a dataset associated with photon emission events; code that identifies a first subset of unscattered events and a second subset of scattered events by estimating a scatter fraction in the photopeak energy window for each pixel; code that determines, for a scattered photon event, a likely location of emission using data from the first subset based upon the at least one characteristic; code that corrects the dataset by associating the scattered photon event with the determined likely location; and code that provides an image generated from the corrected dataset.
The independent claims collectively cover receiving and characterizing photon event datasets (including spatial position and energy), estimating per-pixel scatter fractions to identify scattered events, determining likely emission locations for scattered events using unscattered-event data, correcting the dataset by associating scattered events with those locations, and producing an image from the corrected dataset in method, device, and product forms.
Stated Advantages
Allows more efficient detection using a smaller radiation dose or a shorter examination time or a combination of the two.
Captures useful clinical image information from both unscattered and scattered photon emission events instead of discarding scattered events as noise.
Improves detection efficiency so imaging sessions can be shorter and/or require lower radiological doses.
Improves image contrast and spatial resolution by more effectively removing scatter background and assigning it to the appropriate source distribution.
Improves image quantitation, for example more accurate SUV estimation in SPECT.
Reduces imaging time and lowers costs, potentially improving patient outcomes and providing better imaging data to healthcare professionals.
Documented Applications
Medical imaging, including nuclear medicine modalities such as SPECT and PET.
Security screening, for example airport security checkpoints and baggage screening.
Hand-held devices for use by first responders, security, or assessment teams.
Non-destructive testing applications.
Photon transmission modalities including x-ray CT, x-ray fluorescence, x-ray mammography, and x-ray radiography.
Implementation on consumer mobile devices such as smart phones and tablets containing pixelated optical cameras.
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