Histogram smoothing in positron emission tomography (PET) energy histograms

A nuclear medical imaging method comprising:

• detecting radiation events by a plurality of solid-state detectors, the radiation events localized to a plurality of pixels of the detectors, wherein the solid state detectors includes light sensors and scintillators and each pixel comprises one light sensor coupled one-to-one with one scintillator;
• estimating the energy levels of the detected radiation events as counts of photons detected by the light sensors;
• compressing the estimated energy levels by dropping bits;
• scaling the estimated energy levels with scaling parameters that scale the energy centroids of the plurality of pixels to target values in counts differing by offsets in counts around a common target value in counts, the target values differing with spatial location of the plurality of pixels;
• uncompressing the scaled energy levels by appending different bits subsequent to scaling that were not present during the compressing;
• removing target value offsets from the scaled energy levels;
• and
• combining each of the detected radiation events detected by a grouping of the plurality of pixels or by the entire plurality of pixels into individual energy histograms using the energy levels with the target value offsets removed.

A nuclear medical imaging system, comprising:

• a plurality of solid-state detectors configured to detect radiation events, the radiation events localized to a plurality of pixels of the detectors, wherein the solid state detectors includes light sensors and scintillators and each pixel comprises one light sensor coupled one-to-one with one scintillator;
• at least one processor programmed to:
• estimate the energy levels of the detected radiation events as counts of photons detected by the light sensors;
• compress the estimated energy levels by dropping bits;
• scale the estimated energy levels with scaling parameters that scale the energy centroids of the plurality of pixels to target values in counts differing by offsets in counts around a common target value in counts, the target values differing with spatial location of the plurality of pixels;
• uncompress the scaled energy levels by appending new different bits;
• remove target value offsets from the scaled energy levels;
• and
• generate energy histograms for each of the detected radiation events detected by a grouping of the plurality of pixels or by the entire plurality of pixels using the energy levels with the target value offsets removed.