What is gamma camera resolution?
Gamma cameras have a spatial resolution of 3 to 5 mm. Use of a scintillation crystal for acquisition of data for image formation has led to the labeling of this technique as scintigraphy.
What is the advantage of gamma camera?
Variations from traditional medical imaging
| Advantages of gamma rays | Disadvantages of gamma rays |
|---|---|
| Initially, equipment are less costly | scanning time longer |
| Greater penetrating power | Sources need replacing |
| More portable | Images less sharp |
| Smaller and lighter equipment | Radiation cannot be switched off |
What is gamma camera uniformity?
Rationale: The uniformity or “flood” QC procedure checks that the response of the detector to a source is uniform within defined limits. It is one of the most basic QC tests of the gamma camera.
What is extrinsic uniformity?
Extrinsic uniformity correction has the ability to significantly improve the overall uniformity by taking into account nonuniformities that arise from the collimator. This method improves image quality.
What are gamma cameras made of?
In general, the gamma camera consists of a collimator, a scintillation crystal, and photomultiplier tubes (PMTs).
Does SPECT use a gamma camera?
SPECT imagers have gamma camera detectors that can detect the gamma ray emissions from the tracers that have been injected into the patient. Gamma rays are a form of light that moves at a different wavelength than visible light.
What are disadvantages of gamma rays?
When gamma rays pass through the human body, they ionize the tissue. This method commonly kills cancerous cells, but gamma ray ionization can affect healthy cells. When high levels of gamma rays bombard a body, a resulting dangerous ionization of tissue can cause skin cancer.
What are the disadvantages of using gamma ray?
Disadvantages of gamma rays compared with X-rays
- Poorer quality radiographs.
- Exposure times can be longer.
- Sources need replacing.
- Radiation cannot be switched off.
- Poorer geometric unsharpness.
- Remote handling necessary.
How can the sharpness of a gamma camera image be improved?
“Gamma ray radiation is very powerful so you need heavy shielding to produce a clear image. Most gamma ray cameras use thick lead, but denser materials like tungsten could be as effective while letting more useful radiation pass through to produce higher quality images.”
What is bar phantom?
Determines resolution of scintillation cameras. Bar Phantoms offer precise determination of camera intrinsic resolution, collimator spatial resolution, field size and linearity. E-CAM Bar Phantom (4-Quadrant Phantom) includes two removable screw knobs for insertion/removal of phantom from camera head. …
Why do we need to improve gamma camera performance?
SPECT has highlighted the need to improve gamma camera performance. Flood field nonuniformity is translated into tomographic images as major artifacts because it distorts the data obtained at each projection.
Are there any financial disclosures for gamma cameras?
Disclosures No financial disclosures. Gamma camera images and photographs of equipment are for illustrating concepts and not intended to advertise or endorse any particular manufacturer or vendor. Page 3 Learning Objectives 1. Understand basics of operation of conventional gamma cameras. 2.
What are the dimensions of a gamma camera?
Conventional Gamma Cameras Two detectors (heads) most common, although single head and triple head cameras are used Each head has single large NaI (sodium iodide) crystal, up to 40 cm X 60 cm. Typical crystal thickness: 3/8 or 5/8 inch
How big is the NaI crystal in a gamma camera?
Each head has single large NaI (sodium iodide) crystal, up to 40 cm X 60 cm. Typical crystal thickness: 3/8 or 5/8 inch Array of photomultiplier tubes, typically ~ 50 per head Page 7 Position Determination