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Experimental Physics
Institute of
Experimental Physics

Photo: pixabay.com

Inst. of Experimental Physics

Calorimeters for medical applications

Positron Emission Tomography (PET) is a non-invasive medical imaging technique. This technique is divided into two main steps:

  1. A radioactive tracer is injected into the patient; depending on which body process needs to be observed the tracer is manipulated into different molecules which the bloodstream then carries to the intended target. The tracer then decays, emitting a positron which annihilates with an electron by e+e- annihilation. This annihilation produces two photons.
  2. These two photons then propagate in opposite directions with an energy of 511keV. These are then detected by gamma detectors placed around the patient. These have to have a good energy and time resolution so as to be able to rule out photons affected by Compton scattering and background photon emissions.

It is in the second part of this process which our group contributes to by developing semiconductor based photodetectors with photon count capabilities that when coupled with fast inorganic scintillators produce an increased time and energy resolution. Their insensitivity to magnetic fields paves the path to interlacing PET scans with Magnetic Resonance Imaging (MRI). Furthermore, due to their miniature size they allow for the construction of detectors with extremely high granularity and thus enhanced spatial resolution.

Selected Publications:

  1. Characterization studies of Silicon Photomultipliers and crystals matrices for a novel time of flight PET detector
  2. Chen Xu PHD thesis
  3. Comparison of Digital and Analog Silicon Photomultiplier For Positron Emission Tomography Application (PDF)
  4. Anwendung neuartiger Silizium-Photo-Detektoren in der Positron Emissions Tomographie (PDF)
  5. Entwicklung eines TOF Positron Emissions Tomographie Systems mit MPPC Auslese (PDF)
  6. Towards a Time-of-Flight Positron Emission Tomography System Based on Multi-Pixel Photon Counter Read-out