Normalization of a positron emission tomography scanner

A system for normalization of positron emission tomography (PET), the system comprising:

• a PET scanner comprising a plurality of blocks, each of the plurality of blocks comprising a plurality of rows, each of the plurality of rows comprising a plurality of actual detectors and an unused area comprising a respective region in each of the plurality of rows, the respective region excluding the plurality of actual detectors, the PET scanner configured to acquire a plurality of lines of response (LORs) by scanning a normalization phantom, each respective LOR of the plurality of LORs associated with an actual detector of the plurality of actual detectors;
• a memory having processor-readable instructions stored therein;
• and
• one or more processors configured to access the memory and execute the processor-readable instructions, which, when executed by the one or more processors configures the one or more processors to perform a method, the method comprising:
• obtaining a plurality of actual counts by:
• extracting a plurality of LORs subsets from the plurality of LORs, each of the plurality of LORs subsets associated with a respective actual detector of the plurality of actual detectors;
• and
• counting a number of elements in each LORs subset of the plurality of LORs subsets;
• generating a plurality of virtual detectors in each of the plurality of rows by assigning the unused area to the plurality of virtual detectors;
• fitting a curve to variations of the plurality of actual counts with respect to a plurality of actual positions, each of the plurality of actual positions associated with a respective actual detector of the plurality of actual detectors;
• estimating a plurality of virtual counts associated with the plurality of virtual detectors by extracting a plurality of values from the curve, each of the plurality of values corresponding to a respective virtual position of a plurality of virtual positions, each of the plurality of virtual positions associated with a respective virtual detector of the plurality of virtual detectors;
• and
• applying a normalization process on the plurality of blocks based on the plurality of actual counts and the plurality of virtual counts.

A positron emission tomography (PET) system, comprising:

• a plurality of blocks, each of the plurality of blocks comprising a plurality of rows, each of the plurality of rows comprising a plurality of actual detectors and an unused area comprising a respective region in each of the plurality of rows, the respective region excluding the plurality of actual detectors, each of the plurality of actual detectors configured to acquire a respective line of response (LOR) of a plurality of LORs by scanning a normalization phantom;
• a memory having processor-readable instructions stored therein;
• and
• one or more processors configured to access the memory and execute the processor-readable instructions, which, when executed by the one or more processors configures the one or more processors to perform a method, the method comprising:
• obtaining a plurality of actual counts by:
• extracting a plurality of LORs subsets from the plurality of LORs, each of the plurality of LORs subsets associated with a respective actual detector of the plurality of actual detectors;
• and
• counting a number of elements in each LORs subset of the plurality of LORs subsets;
• generating a plurality of virtual detectors in each of the plurality of rows by assigning the unused area to the plurality of virtual detectors;
• generating a count profile for the plurality of actual detectors, the count profile associated with the plurality of actual counts;
• estimating a plurality of virtual counts associated with the plurality of virtual detectors based on the count profile;
• and
• applying a normalization process on the plurality of blocks based on the plurality of actual counts and the plurality of virtual counts.