Single Photon Emission Tomography (SPECT) is a diagnostic tool used to detect single photons from radionuclide tracers, aiding in the reconstruction of 3D images for medical evaluations, including tumor detection and bone scans. The technique relies on gamma-ray photons emitted from radiopharmaceuticals and typically utilizes thallium-activated sodium iodide detectors with a specific radiopharmaceutical for imaging. While SPECT provides valuable functional information, it is generally inferior to Positron Emission Tomography (PET) in terms of resolution and sensitivity.

1. SINGLE PHOTON EMISION
TOMOGRAPHY
SIR SYED UNIVERSITY OF ENGINEERING AND
TECHNOLOGY
SYED HAMMAD
AKHTER
2012-BM-071
PRESENTED TO
ENGR. FAHAD
AKBER

2.  Detect single photons emitted by
radionuclide tracers
 Determine the origin and direction of
emitted gamma
 Reconstruct 3D images of the source or
anatomy
 Used as a diagnostic tool to image
tumors, disease, and perform bone scans
The images reflects functional
infformation avout patients similar to that
obtained with PET
Works with Gamma rays

3.  Gamma-ray photons emitted from
the internal distributed
radiopharmaceutical (tracer) penetrate
through the patient’s body.
 Detected by a single or a set of
collimated radiation detectors.
 Most of the detectors used in
current SPECT systems are based on
a single or multiple NaI(TI) scintillation
detectors.
 In SPECT, projection data are
acquired from different views around
the animal/patient.
Technetium -99
Meta stable nuclear isomer of TC-99
Symbolized as TC-99m that is used in terms of
million of medical diagnostic procedures

4. Thallium activated Sodium Iodide
Detectors of gamma rays
It is sensitive to gamma rays and convert into light
Radionucleotide Main emision
energy
Half life
Tc-99m 140 6.02 hrs
Ti-201 69,71,80 73 hrs
I-123 159 13 hrs
In-111 1,7,245 2.83 days
Xe-133 81 5.25 days

5. • SPECT imaging is inferior to PET because of attainable resolution and
sensitivity. Different radionuclide is used for SPECT imaging that emits a
single photon rather than positron emission as in PET.
• The use of collimator results in a tremendous decrease in the detection
efficiency as compared to PET
SPECT Scan
Uses• Pre-surgical evaluations of uncontrolled
seizures
• Finding stress fractures in spine
(Spondylolysis)
• Blood deprived areas of the brain after a
stroke
• Detects tumors
Role of Neuroimaging in Alzheimer's
Disease, with Emphasis on Brain
Perfusion SPECT