What are the two most important QC procedures that must be performed on a scintillation gamma camera?
QC of Planar Imaging Systems Changes in photopeak location, photomultiplier tube (PMT) performance, energy and linearity correction, etc all affect image uniformity. Hence this is probably the single most important QC test that can be performed on a gamma camera system and one that should be performed on a daily basis.
What is the resolution of SPECT?
Recently developed single photon emission computed tomographic (SPECT) scanners dedicated for small animal imaging are of interest due to their excellent spatial resolution of <1 mm, but few studies have focused on the evaluation of intratumoral heterogeneity.
What is the most likely cause of loss of resolution in SPECT?
Most common cause of defects in the reconstructed images are due to nonuniformity of the detector. Examples: Correction matrix is the wrong size, correction map is out of date, wrong radioisotope setting, or some form of electronic failure.
What is the difference between gamma camera and SPECT?
SPECT (Single-Photon Emission Computed Tomography) is a diagnostic imaging technique used in nuclear medicine which studies PHYSIOLOGICAL (FUNCTIONAL) processes in the body. Gamma cameras are used to construct an image of the distribution of radiopharmaceuticals spread out in the body of a patient.
What is collimator resolution?
Collimator resolution, which refers to the sharpness or detail of the ‘Y-ray image projected onto the detector, also is rather poor, generally worse than the intrinsic resolution of the camera detector and electronics.
What is a pinhole collimator?
Pin-Hole Collimator. Another type of collimator that is used with gamma camera is the “pinhole” collimator, which consists of a lead cone with only one hole in the end. The pinhole offers superb resolution and extreme magnification, but suffers from very poor sensitivity.
What is spatial resolution in SPECT?
The intrinsic resolution of gamma camera is about 3-4 mm and tomographic SPECT acquisition reveals a spatial resolution, as mentioned above, not better than 10 mm.
What is SPECT used for?
The most common uses of SPECT are to help diagnose or monitor brain disorders, heart problems and bone disorders.
What is center of rotation in SPECT?
Center of Rotation artifact: The detectors of a SPECT camera rotate around a central axis. The computer makes assumptions about the location of this axis during image reconstruction. The center of rotation corrects for the difference between the center of the computer matirx and the projection of the cameras face.
How does a SPECT camera work?
The SPECT machine is a large circular device containing a camera that detects the radioactive tracer your body absorbs. During your scan, you lie on a table while the SPECT machine rotates around you. The SPECT machine takes pictures of your internal organs and other structures.
Why collimator is used in SPECT?
A collimator is a device used to restrict the photon acceptance angle to provide positional information for detected photons. A SPECT collimator is a thick sheet of metal of high atomic number, usually lead or tungsten, pierced by an array of holes.
What collimator is used for SPECT?
The most commonly used radionuclide for SPECT is 99m-technetium (99mTc), which has a main photo peak at 140.5 keV and a half-life of 6.01 h.
What are the QC guidelines for SPECT analysis?
Assesses adequacy of COR corrections observed in sinogram and linogram 4. Assesses overall SPECT resolution and contrast Recommended – QC Guidelines Annually 1. Intrinsic uniformity, spatial resolution, & linearity 2. System uniformity- check all collimators 3. Sensitivity- verify that count rate per unit activity per detector is satisfactory 4.
What is quality control (QC) in PET/SPECT?
Quality control (QC) of single-photon emission computed tomography (SPECT) and positron emission tomography (PET) nuclear cardiology procedures is a multiple-step process that begins before the patient enters the laboratory, continues during the acquisition, and after the patient leaves the laboratory.
What are the protocols for SPECT MPI?
This chapter will describe protocols for SPECT MPI for the two primary imaging agents, thallium-201 and technetium-based products. The primary indication for a SPECT MPI study is the assessment of the relative distribution of coronary flow in patients with suspected or known CAD.
How is SPECT acquired and used in the diagnosis process?
After an appropriate uptake period, the patient is placed on the imaging table and the SPECT acquisition begins. A static gamma camera image is acquired at a particular angle. The camera then rotates to the next position and a second projection image is acquired. This process continues until a full set of projections is acquired about the patient.