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.

QUESTIONS????