Minimals: Tomography Flashcards
What is the operation principle of gamma camera?
A substance labeled with radioactive isotope is injected into the body(radiopharmacon). The emitted gamma photon passes through a collimating and collided into a scintillation detector. The distribution of the radiation source can be mapped by the counts of photomultiplier times connected to the detector.
Most important types of applications of radio isotopes in medical diagnosis
- in vitro lab tests
- determination of the volume of body compartments
- 2D or 3D imaging of the distribution of radioactive isotopes in the body
What is the principle of SPECT?
Images are taken form different directions by a gamma camera. The three dimensional distribution of the radiation source is calculated from these images.
What kind of isotopes can be used in PET?
Nuclei with beta positive decay
What is the principle of CT
X-Ray images are taken of the human body from different directions. The X-ray absorption capacity of volume units (voxels) of the body can be calculated from these images.
In which respect does a CT image provide more info than a conventional X-ray image?
A conventional X-ray image contains only the 2D projection of the distribution of the X-ray absorbing material. The CT image also reveals the third dimension (depth) of the object.
