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From X-ray Astronomy to Gamma Scintigraphy: Designs on High Resolution Medical Imaging Dr. John Lees Space Research Centre University of Leicester
From X-ray Astronomy to
Gamma Scintigraphy:
Designs on High Resolution Medical Imaging
Dr. John Lees
Space Research Centre
University of Leicester
Space Research Centre
Recent Space Missions
XMM-Newton
Chandra
Swift
Space Research Centre
Chandra image
Left: X-ray image from Chandra. Right: composite images from Chandra and
Hubble. The Cat’s Eye Nebula, also know as NGC 6543. Scale 30 arcsec a side.
Space Research Centre
Mini Gamma Ray Camera (MGRC)
• High spatial resolution (<1mm)
• Complementary to “standard” Gamma Camera (5-8mm).
• For imaging small sites of radiopharmaceutical uptake in tissue
• Images gamma photons
• High spatial resolution
• Scintillator coated CCD
• Energy range 30-160 keV.
• International Patent
Space Research Centre
Why do this?
• Clinical need for high resolution imaging
• Standard Gamma camera: 5 – 10 mm spatial resolution
• Need for sub-mm spatial resolution
• High energy photons ? - 99mTc (140 keV gamma-rays)
• Point of care testing
• Tumour detection, Sentinel Lymph Nodes, Thyroid …
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Clinical Need
lacrimal drainage
(eye)
Sentinel node
detection
(breast)
Sentinel node
detection
skin (melanoma)
Joint
imaging
Nasal clearance
(drug delivery
studies)
General surgical
exploration
in bone (osteoid osteoma)
tumour detection, (colon,
ovary).
thyroid
morphology
Space Research Centre
Sentinel Node Detection
RCS New Start Programme 2007-2008:Sentinel Lymph Node Biopsy Training Programme
Regionally run programme aimed at all members of the breast care team.
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“Standard” gamma camera
Space Research Centre
Non Imaging Probes
Photograph of intra-
operative procedure
with a nuclear probe
detector.
Space Research Centre
MGRC Applications
Clinical use:• Sentinel lymph node imaging• Intra-operative tumour localisation• Renal transplant function• Gastrointestinal transit• Assessment of aspiration in acute stroke patients• Lacrimal drainage (eye)• Thyroid morphology
Non-clinical use:
• Veterinary medicine eg. small animals
• Small animal drug development models
• Regional contamination monitoring• Non Destructive Testing
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MGRC Schematic
Collimator
Scintillator
CCD or CMOS
Device + electronics
20mm
500µm
60mm
Columnar CsI
Each column acts as a “light pipe”
Reduced light loss
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Comparison of MGRC with “Standard” Gamma Camera
99mTc image,140 keV gamma rays, 10 minutes exposure
Two 2mm dia. holes, one 3mm dia. hole on 5mm pitch
5 mm
GEC Maxicamera 400MGRC
Space Research Centre
Automatic Scale Selection
What: A image analysis technique used to identify and measure “blobs”
Why: Need a way to analyse “light splashes” from Mini Gamma Ray
Camera images
Gives best fit to “Gaussian splashes” with no a priori assumption on
2 or amplitude
Can extract energy resolution
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99mTc filled phantom
Raw image
single frame
Cleaned up image
500 frames
Cleaned up image
single frame2 A
1.18 2053
1.45 605
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Comparison of MGRC with “Standard” Gamma Camera
Comparison of MGRC with “standard” gamma camera
MGRC with pinhole
collimator
GE Maxicam 400
Gamma camera
6mm 5mm
Miniature hot spot phantom
4, 3 and 2mm holes
11mm
11mm
Space Research Centre
MGRC Image
Mouse phantom99mTc image of leg and hips
10 mm
10 mm
Space Research Centre
Animal Imaging
Mouse injected with 99mTc-labelled aptamer
Image one hour after injection
12mm
Uptake @ Tumour
Bladder
Space Research Centre
Development Goals
• Optimisation of the current laboratory
demonstrator MGRC
• Testing of the MGRC in the clinical environment
• Evaluation of results and design modification.
• A CE marked MGRC
• Pilot trials with clinicians and surgeons
Space Research Centre
Acknowledgements
• Space Research Centre, Leicester
David Bassford, Oliver Blake, Tony Abbey,
George Fraser and Tim Maskell
• University of Nottingham
Alan Perkins and Elaine Blackshaw
