Apparatus and method for measuring depth-of-interaction using light dispersion and positron emission tomography using the same

A Positron Emission Tomography (PET) device using light dispersion comprising:

• a device for measuring a Depth-Of-Interaction (DOI) using the light dispersion, the device comprising
• a crystal layer of a mono layer in which a plurality of crystals for absorbing gamma rays are adjacent and consecutively arranged,
• scintillation light detectors disposed at one end of the crystals and configured to detect scintillation light emitted from the crystal layer by the gamma rays,
• a change material included in the crystals and configured to linearly change transmittance in a length direction of the crystals, and
• a control unit configured to calculate the DOI in the crystal layer on a basis of a first output signal and the second output signal,
• the scintillation light detectors outputting the first output signal in one direction and the second output signal in a direction perpendicular to the one direction,
• said control unit configured to calculate the DOI of the crystal layer by at least
• calculating an amount of a variance value of photon distribution in each of the directions on the basis of the first output signal and the second output signal,
• inducing an angle of the DOI on the basis of the variance value of the number of photons, and
• calculating the DOI on the basis of the angle of the DOI.

A method of measuring a Depth-Of-Interaction (DOI) using light dispersion, the method comprising:

• emitting scintillation light from specific positions of a plurality of crystals, which have absorbed gamma rays;
• the crystals or reflective films having a linearly changing transmittance in a length direction of the crystals and controlling a degree of dispersion of scintillation light;
• using scintillation light detectors, disposed on one end of the crystals, to detect the scintillation light;
• using the scintillation light detectors, each detecting first output signal according to one direction corresponding to the scintillation light and a second output signal according to a direction at a right angle to the one direction;
• and
• using a control unit to calculate the DOI of the crystal on a basis of the first output signal and the second output signal by at least
• calculating an amount of a variance value of photon distribution in each of the directions on the basis of the first output signal and the second output signal,
• inducing an angle of the DOI on the basis of the variance value of the number of photons, and
• calculating the DOI on the basis of the angle of the DOI.