Method and system of random-event-based count-rate adaptive normalization for PET detector efficiency

A method for generating crystal efficiency correction factors by performing a normalization calibration based on delayed data independent of a phantom in a Positron Emission Tomography (PET) apparatus, comprising:

• obtaining delayed data from modules of a PET scanner;
• generating a sinogram from the obtained delayed data only;
• determining, mean fan response sensitivity and block line response sensitivity based on the generated sonogram by using a processing circuit;
• determining, using the processing circuit, a mean detector efficiency for each module based on the determined mean fan response sensitivity and block line response sensitivity;
• determining, using the processing circuit, an individual crystal efficiency of each module based on the determined mean fan response sensitivity and block line response sensitivity and the mean detector efficiency;
• calculating the crystal efficiency correction factors based on the determined individual crystal efficiency;
• and
• calibrating the PET scanner by using the calculated crystal efficiency correction factors to reduce quantitative error and artifacts in image reconstruction by the PET apparatus,
• wherein each module is a detector having a plurality of crystals, and
• wherein the obtained delayed data corresponds to patient random paired event data.

A Positron Emission Tomography (PET) apparatus for generating crystal efficiency correction factors by performing a normalization calibration based on delayed data independent of a phantom, the apparatus comprising:

• processing circuitry configured to:
• obtain delayed data from a scan of a patient using modules of a PET scanner;
• generate a sinogram from the obtained delayed data;
• determine mean fan response sensitivity and block line response sensitivity based on the generated sonogram by using a processing circuit;
• determine a mean detector efficiency for each module based on the determined mean fan response sensitivity and block line response sensitivity;
• determine an individual crystal efficiency of each module based on the determined mean fan response sensitivity and block line response sensitivity and the mean detector efficiency;
• and
• calculate the crystal efficiency correction factors based on the determined individual crystal efficiency;
• and
• calibrate the PET scanner by using the calculated crystal efficiency correction factors to reduce quantitative error and artifacts in image reconstruction by the PET apparatus,
• wherein each module is a detector having a plurality of crystals, and
• wherein the obtained delayed data corresponds to patient random paired event data.

A Positron Emission Tomography (PET) apparatus for generating crystal efficiency correction factors by performing a normalization calibration based on delayed data independent of a phantom, comprising:

• processing circuitry configured to:
• obtain delayed data from modules of a PET scanner;
• generate a sinogram from the obtained delayed data only;
• determine mean fan response sensitivity and block line response sensitivity based on the generated sonogram by using a processing circuit;
• determine a mean detector efficiency for each module based on the determined mean fan response sensitivity and block line response sensitivity;
• determine an individual crystal efficiency of each module based on the determined mean fan response sensitivity and block line response sensitivity and the mean detector efficiency;
• calculate the crystal efficiency correction factors based on the determined individual crystal efficiency;
• and
• calibrate the PET scanner by using the calculated crystal efficiency correction factors to reduce quantitative error and artifacts in image reconstruction by the PET apparatus,
• wherein each module is a detector having a plurality of crystals, and
• wherein the obtained delayed data corresponds to patient random paired event data.