molecular imaging & positron emission tomography
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Molecular Imaging & Positron Emission Tomography . Nicholas Mulhern BME 281. Molecular Imaging. Produces Images of the body Allows Visualization of the cellular function Fine molecular changes understanding molecular pathways Allows for quantitative tests - PowerPoint PPT PresentationTRANSCRIPT
Molecular Imaging &Positron Emission Tomography
Nicholas Mulhern BME 281
Molecular Imaging• Produces Images of the body• Allows Visualization of the cellular function• Fine molecular changes• understanding molecular pathways
• Allows for quantitative tests• More objectivity to the study of Specific Areas
• Noninvasive manner• Origins in the 1950’s
Why its important?• Earlier and more precise Disease diagnosis• Cancer• Neurological • Cardiovascular diseases
• Elucidate biochemical processes• Track the impact of experimental drugs• clinical trials
• Many Applications • Oncology, Neuroimaging, Cardiology, Pharmacology Small animal
imaging, Musculo-skeletal imaging
(PET) • Provides a three-dimensional image or picture of functional
processes in the body• blood flow • other biochemical functions
Biomarkers
• Injected into Patient• tagged with a radioactive atom
• Molecule determines the function imaged
• Indicator of the Biological state• Help image particular targets or
pathways• Chemically interact with their
surroundings • Alter Images according to Molecular
changes• Carbon-11, Fluorine-18, Oxygen-15, or
Nitrogen-13• short decay time positron emitting radionuclide
Fluorodeoxyglucose (FDG)
Gamma Ray Detector• Flat table moves incrementally within Housing • Circular Gamma ray detector Array
• “Donut Shaped”• Contains series of scintillation crystals• connected to a photomultiplier tube
• Scintillation crystals• convert the gamma rays, emitted from the patient, to photons of light
• Photomultiplier Tubes • Convert and amplify the photons to electrical signals
Electrical signals • Electrical signals are then processed by the computer to
generate images• The table is then moved• process is repeated• Time Dedication• 60 min Resting Period• Scan 30 minutes
• Analytical results within • 24 hours
Result Imaging
• Resulting in a series of thin slice images • Region of interest • brain, breast, liver• These thin slice images can be assembled into a 3D representation of
the patient's body
shows that leukemia present in the bone marrow before treatment, left, persisted after chemotherapy, right.
Brain scans of a healthy person (top of image) and a person with schizophrenia (bottom)
Today • Few PET centers in the country • Must be located near a particle accelerator device • It produces the short-lived radioisotopes used in the technique
• PET/CT scanner "co-registration" • Combines CT X-ray Scan simultaneously • Provides Anatomic Info: what the structure is • Metabolic Inform: what it is doing biochemically
• TIME Magazine as the medical invention of the year in 2000
A complete body PET/ CT Fusion Image
Sources• http://www.rikenresearch.riken.jp/eng/frontline/6414• http://mips.stanford.edu/grants/icmic/2010-2015/• http://www.howstuffworks.com/nuclear-medicine1.htm• http://blog.cleveland.com/medical/2009/03/
is_my_chemo_working_new_use_fo.html• http://sitemaker.umich.edu/pet.chemistry/
positron_emission_tomography• http://www.biologyreference.com/Po-Re/Psychiatric-
Disorders-Biology-of.html#b