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SPECTTara Conrad
Ana PenaChristina Elder
Paul Mozo
Single photon emission computed tomography (SPECT) is a nuclear medicine imaging technique using gamma rays.
Images primarily the biological process or function of organs rather than anatomical structure.
Uses a gamma camera to acquire multiple 1D projection images which are then processed and converted into 2-D images using the mathematical technique of computer tomography.
Multiple slices are obtained simultaneously and stacked to form a 3D representation.
To acquire the images, the gamma camera is rotated around the patient. Projections are typically acquired every 3-6 degrees. Generally, a full 360 degree rotation is used to obtain an optimal reconstruction.
Principles of SPECT
http://www.spect.net/
Multi-headed gamma cameras can provide accelerated acquisition. 15 – 20 seconds is the typical time to obtain each projection. This gives a total scan time of 15-20 minutes.
A nuclide in a radiopharmaceutical is placed into the body by either injection, oral or inhalation. It consists of an emitting isotope.
Photons travelling in the desired direction pass through the collimator towards the detector; other photons are absorbed by the collimator.
Process
Aston Medical Imaging test page 87http://www.ajnr.org/cgi/content/full/29/7/1247Radiation detectors for medical applications By Stefaan Tavernier, Boris Grinyovhttp://venda.uku.fi/~aoseppan/SPECTthesis.pdf
A gamma ray photon interacts with the detector (NaI:Tl crystal) by means of the Photoelectric Effect or Compton Scattering with the iodide ions of the crystal.
This interaction causes the release of electrons which in turn interact with the crystal lattice to produce light, in a process known as scintillation.
Process
http://www.physics.ubc.ca/~mirg/home/tutorial/hardware.htmlhttp://upload.wikimedia.org/wikibooks/en/4/43/NM6_3.gif http://mxp.physics.umn.edu/s04/Projects/s04xrf/xrf_1.gif
These photons are then detected by a collection of photomultiplier tubes (PMTs)
Relative reading from the PMTs are used to compute the spatial coordinates of the gamma rays
Each PMTs outputs an electrical current proportional to the number of light photons detected.
Process
Radiation detectors for medical applications By Stefaan Tavernier, Boris Grinyovhttp://venda.uku.fi/~aoseppan/SPECTthesis.pdf http://www.physics.ubc.ca/~mirg/home/tutorial/pics/pmt.gif
www.frankswebspace.org.uk/.../gammaCamera2.gif
History of SPECT 1940's crude spatial information about radioactive source distributions within the brain were produced using a single detector positioned at various locations around the head.
1951 Ben Cassen invented the rectilinear scanner. It produced planar images by mechanically scanning a detector in a raster-like
pattern over the area of interest. Only photons directly under the moving scanner could be detected at any given time Long Imaging times
1953 Hal Anger reported the first gamma camera It used a pin-hole configuration Produced images on a large piece of photographic paper Long exposure times and high radiation doses.
http://www.physics.ubc.ca/~mirg/home/tutorial/history.htmlhttp://interactive.snm.org/docs/hist_corner_11_03.pdf http://wwwx.cs.unc.edu/~sud/courses/comp235/pinhole-principle.gif
History of SPECT
1963 Kuhl and Edwards presented for the first time, tomographic images produced using the Anger Camera
1957 Anger replaced the film and screen with a single NaI crystal and PMT array. This was the first Anger scintillation camera
Modern Anger Cameras use a lead collimator perforated with many parallel, converging or diverging holes instead of the original pin-hole configuration.
Resolution is determined by size of collimator holes
http://www.physics.ubc.ca/~mirg/home/tutorial/pics/camera2.gifhttp://www.physics.ubc.ca/~mirg/home/tutorial/history.html
History of SPECT1977 Everett, Fleming, Todd and Nightengale suggested the use of the Compton effect for gamma-radiation imaging
1980’s FASTSPECT Incorporates an array of gamma-ray cameras to simultaneously record enough planar
images without camera motion. All projections are collected at the same time, so total data-collection period is that
required for a single planar image. Too complex and high increase in price
1983 Manbir Singh and David Doria proposed and experimented the use of the Compton Camera for SPECT because: Mechanical collimation is replaced with electronic collimation Huge gains in sensitivity (this compromises resolution) Reduction in radiation dosage
http://www.freepatentsonline.com/5175434.htmlhttp://ns.ph.liv.ac.uk/~ang/Public/2ndyr_posterday.pdf
http://iopscience.iop.org/0031-9155/49/8/002/http://www.physics.ubc.ca/~mirg/home/tutorial/history.html
FASTSPECT
History of SPECT 2004 FastSPECT II
16-camera small-animal SPECT imager built with modular scintillation cameras Enough modular cameras to collect entire data set without camera or imaging subject
motion Enlarged camera active area with larger PMT array Lead-shielded enclosure Improved calibration and positioning system Specifically designed for small-animal imaging
http://search.vadlo.com/b/q?rel=2&keys=PPT+about+FastSPECThttp://www.radiology.arizona.edu/cgri/Publications_PDF/Publications/2002/....FastSPECT%20II--A%20Second-Generation%20High-Resolution%20Dynamic%20SPECT%20Imager.pdf
History of SPECT 2008 Shinji Motomura et al Spectrom, demonstrated the feasibility of compton cameras for multiple molecular imaging. Camera has:
Two double-sided orthogonal-strip germanium detectors Their excellent energy resolution enables discrimination of the nuclides Accurate determination of the scattering angle for rays in wide energy range
http://www.rsc.org/publishing/journals/JA/article.asp?doi=b802964d
History of SPECT 2010 ProSPECTus designed by the University of Liverpool's Nuclear Physics research
group alongside the Nuclear Physics Group at STFC Daresbury Laboratory
Improving future diagnosis of cancer and the probability of successful cancer therapy. Technology based on Compton Camera Much less of the radiation used in the process is wasted 100 times more sensitive than existing clinical SPECT systems. Increased sensitivity offers two benefits
dose of radiation administered to the patient could be reduced or alternatively more patients could be scanned by one machine in a day if the
current dose is used.
http://www.sciencedaily.com/releases/2010/03/100303113956.htm
U-SPECTU-SPECT is an application that is used for veterinary purposes rather than normal medical purposes
http://www.milabs.com/pages/preclinical-imaging/u-spect-ii.php
D-SPECT
http://www.phas.ubc.ca/~mirg/projects/dspect_renal/dspect_renal.htmlhttp://www.medgadget.com/archives/2005/12/dspect_cardiac.html
Dynamic single positron emission computed tomography (D-SPECT) is a new technology used to improve the resolution and specificity
Heart SPECT Renal SPECT
SPECT Applications
Heart Imaging
Brain Imaging
Renal Imaging
Bone Scans
Parathyroid Scans
http://radiographics.rsna.org/content/28/5/1461/F13.large.jpghttp://www.phas.ubc.ca/~mirg/projects/dspect_renal/dspect_renal.html
Heart ImagingIdentify blockagesDiagnose a heart attackPredict probability of a heart attackAssess a patient’s condition after bypass surgery or angioplastyAdditional applications include SPECT myocardial perfusion imaging (MPI)
http://interactive.snm.org/index.cfm?PageID=5210http://healthimaging.com/index.php?option=comarticles&view=article&id=16089
Brain Imaging Help differentiate between types of dementiaHelp clinicians study Alzheimer's DiseaseIdentify specific areas of the brain affected by traumaIdentify effects of medication and drugs on the brainIdentify areas affect by seizures and toxics
http://www.amenclinics.com/brain-science/spect-research/
Trauma Alcohol Abuse Drug Abuse
Renal ImagingSPECT scan canDetect tumorsDamaged areas in kidneys Glomerular flow rate
http://www.amenclinics.com/brain-science/spect-research/
Non-Medical Application Gamma-Ray Spectrometer
(GRIS)
Uses:InspectionsMapping radio active contamination
https://www.llnl.gov/str/September04/Labov.htmlhttps://www.globalsecurity.org/security/systems/gris.htm
Provides 3D Images
Good Image Contrast
Physical and Functional imaging that is accurate and reliable for diagnostics
Cardiac Gated Acquisitions are possible with SPECT
High diagnostic ability for bone scintigraphy com pared to MRI
Advantages
http://www.nupecc.org/iai2001/report/B22.pdfhttp://www.answers.com/topic/single-proton-emission-computed-tomographyhttp://www.addadhadvances.com/SPECT.html
DisadvantagesPoor Resolution
Takes a long time scanning
Radiation exposure
Not safe for pregnant women
Bleeding, pain or swelling can occur at the injection site
Sensitive to motion
Costly
Not widely available
http://www.nupecc.org/iai2001/report/B22.pdfhttp://jnm.snmjournals.org/cgi/reprint/42/7/1050http://www.medscape.com/viewarticle/524979
Cost per Scan Average cost of a SPECT scan is $1,000-
$1,900
Amen Clinic evaluation is $3,300
Bone Scan with Medicare costreduced from $2,191 to $1,865
http://www.med.umich.edu/alzheimers/PDF/scan.pdfhttp://www.wired.com/medtech/health/magazine/16-06/mf_neurohacks?currentPage=allhttp://www.birf.info/home/library/med-procede/med-pro-spect.htmlhttp://addadhdadvances.com/SPECT.htmlhttp://www.medscape.com/viewarticle/538502
2007: 15.9 million SPECT procedures performed
Annual Scans
http://www.dicardiology.net/node/28668/http://www.physics.ubc.ca/~mirg/home/tutorial/applications.html
Cost of the SPECT MachineSPECT machine costs $400,000 to $650,000
http://www.dicardiology.net/node/28668/http://www.lexch.com/articles/2010/03/15/news/regional/doc4b9e42e32a4e2379812670.txthttp://www.world-widemedical.com/Detail.CFM?LineItemID=524http://www.neurologica.com/inspira-hd.html
inSPira HD base price is $479,900 with additional accessories around $539,900
Special Thanks to Matt Jacobs the
Mid-South East Sales Representative of
NeuroLogica Corporation for his time and pricing information.
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