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Concept of an upright wearable positron emission tomography imager in humans

View Article: PubMed Central - PubMed

ABSTRACT

Background: Positron Emission Tomography (PET) is traditionally used to image patients in restrictive positions, with few devices allowing for upright, brain‐dedicated imaging. Our team has explored the concept of wearable PET imagers which could provide functional brain imaging of freely moving subjects. To test feasibility and determine future considerations for development, we built a rudimentary proof‐of‐concept prototype (Helmet_PET) and conducted tests in phantoms and four human volunteers.

Methods: Twelve Silicon Photomultiplier‐based detectors were assembled in a ring with exterior weight support and an interior mechanism that could be adjustably fitted to the head. We conducted brain phantom tests as well as scanned four patients scheduled for diagnostic F18‐FDG PET/CT imaging. For human subjects the imager was angled such that field of view included basal ganglia and visual cortex to test for typical resting‐state pattern. Imaging in two subjects was performed ~4 hr after PET/CT imaging to simulate lower injected F18‐FDG dose by taking advantage of the natural radioactive decay of the tracer (F18 half‐life of 110 min), with an estimated imaging dosage of 25% of the standard.

Results: We found that imaging with a simple lightweight ring of detectors was feasible using a fraction of the standard radioligand dose. Activity levels in the human participants were quantitatively similar to standard PET in a set of anatomical ROIs. Typical resting‐state brain pattern activation was demonstrated even in a 1 min scan of active head rotation.

Conclusion: To our knowledge, this is the first demonstration of imaging a human subject with a novel wearable PET imager that moves with robust head movements. We discuss potential research and clinical applications that will drive the design of a fully functional device. Designs will need to consider trade‐offs between a low weight device with high mobility and a heavier device with greater sensitivity and larger field of view.

No MeSH data available.


Top Left: The actual multicompartmental phantom used for imaging. Top Right: A 12‐mm reconstructed slice of the phantom. The phantom was reconstructed in 1‐mm slices, and then grouped together to form a 12‐mm slice. Bottom: Four consecutive central 1‐mm phantom slices
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brb3530-fig-0003: Top Left: The actual multicompartmental phantom used for imaging. Top Right: A 12‐mm reconstructed slice of the phantom. The phantom was reconstructed in 1‐mm slices, and then grouped together to form a 12‐mm slice. Bottom: Four consecutive central 1‐mm phantom slices

Mentions: In addition, the grey matter compartment of the Hoffmann phantom was equally filled with a low level of F18‐FDG tracer (less than 100 μCuries) and imaged for 4 hr. Reconstructed images were iterated 10 times and binned into 1‐mm slices. The images were displayed in ImageJ (Fig. 3).


Concept of an upright wearable positron emission tomography imager in humans
Top Left: The actual multicompartmental phantom used for imaging. Top Right: A 12‐mm reconstructed slice of the phantom. The phantom was reconstructed in 1‐mm slices, and then grouped together to form a 12‐mm slice. Bottom: Four consecutive central 1‐mm phantom slices
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036439&req=5

brb3530-fig-0003: Top Left: The actual multicompartmental phantom used for imaging. Top Right: A 12‐mm reconstructed slice of the phantom. The phantom was reconstructed in 1‐mm slices, and then grouped together to form a 12‐mm slice. Bottom: Four consecutive central 1‐mm phantom slices
Mentions: In addition, the grey matter compartment of the Hoffmann phantom was equally filled with a low level of F18‐FDG tracer (less than 100 μCuries) and imaged for 4 hr. Reconstructed images were iterated 10 times and binned into 1‐mm slices. The images were displayed in ImageJ (Fig. 3).

View Article: PubMed Central - PubMed

ABSTRACT

Background: Positron Emission Tomography (PET) is traditionally used to image patients in restrictive positions, with few devices allowing for upright, brain‐dedicated imaging. Our team has explored the concept of wearable PET imagers which could provide functional brain imaging of freely moving subjects. To test feasibility and determine future considerations for development, we built a rudimentary proof‐of‐concept prototype (Helmet_PET) and conducted tests in phantoms and four human volunteers.

Methods: Twelve Silicon Photomultiplier‐based detectors were assembled in a ring with exterior weight support and an interior mechanism that could be adjustably fitted to the head. We conducted brain phantom tests as well as scanned four patients scheduled for diagnostic F18‐FDG PET/CT imaging. For human subjects the imager was angled such that field of view included basal ganglia and visual cortex to test for typical resting‐state pattern. Imaging in two subjects was performed ~4 hr after PET/CT imaging to simulate lower injected F18‐FDG dose by taking advantage of the natural radioactive decay of the tracer (F18 half‐life of 110 min), with an estimated imaging dosage of 25% of the standard.

Results: We found that imaging with a simple lightweight ring of detectors was feasible using a fraction of the standard radioligand dose. Activity levels in the human participants were quantitatively similar to standard PET in a set of anatomical ROIs. Typical resting‐state brain pattern activation was demonstrated even in a 1 min scan of active head rotation.

Conclusion: To our knowledge, this is the first demonstration of imaging a human subject with a novel wearable PET imager that moves with robust head movements. We discuss potential research and clinical applications that will drive the design of a fully functional device. Designs will need to consider trade‐offs between a low weight device with high mobility and a heavier device with greater sensitivity and larger field of view.

No MeSH data available.