Spatial distortion correction and crystal identification for position-sensitive avalanche photodiode-based PET scanners

Abhijit Chaudhari, Anand A. Joshi, Yibao Wu, Richard M. Leahy, Simon R Cherry, Ramsey D Badawi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Position-sensitive avalanche photodiodes (PSAPDs) are gaining widespread acceptance in modern PET scanner designs, and owing to their relative insensitivity to magnetic fields, especially in those that are MRI-compatible. Flood histograms in PET scanners are used to determine the crystal of annihilation photon interaction and hence, for detector characterization and routine quality control. For PET detectors that use PSAPDs, flood histograms show a characteristic pincushion distortion when Anger logic is used for event positioning. A small rotation in the flood histogram is also observed when the detectors are placed in a magnetic field. We first present a general purpose automatic method for spatial distortion correction for flood histograms of PSAPD-based PET detectors when placed both inside and outside a MRI scanner. Analytical formulae derived for this scheme are based on a hybrid approach that combines desirable properties from two existing event positioning schemes. The rotation of the flood hist gram due to the magnetic field is determined iteratively and is accounted for in the scheme. We then provide implementation details of a method for crystal identification we have previously proposed and evaluate it for cases when the PET scanner both outside and in a magnetic field. In this scheme, Fourier analysis is used to generate a lower-order spatial approximation of the distortion-corrected PSAPD flood histogram, which we call the 'template'. The template is then registered to the flood histogram using a diffeomorphic iterative intensity-based warping scheme. The calculated deformation field is then applied to the segmentation of the template to obtain a segmentation of the flood histogram. A manual correction tool is also developed for exceptional cases. We present a quantitative assessment of the proposed distortion correction scheme and crystal identification method against conventional methods. Our results indicate that our proposed methods lead to a large reduction in manual labor and indeed can outinely be used for calibration and characterization studies in MRI-compatible PET scanners based on PSAPDs.

Original languageEnglish (US)
Title of host publicationIEEE Nuclear Science Symposium Conference Record
Pages5045-5052
Number of pages8
DOIs
StatePublished - 2008
Event2008 IEEE Nuclear Science Symposium Conference Record, NSS/MIC 2008 - Dresden, Germany
Duration: Oct 19 2008Oct 25 2008

Other

Other2008 IEEE Nuclear Science Symposium Conference Record, NSS/MIC 2008
CountryGermany
CityDresden
Period10/19/0810/25/08

Fingerprint

Avalanches
avalanches
scanners
photodiodes
histograms
Magnetic Fields
crystals
templates
detectors
magnetic fields
positioning
labor
Anger
Fourier analysis
Fourier Analysis
quality control
Photons
acceptability
Quality Control
Calibration

Keywords

  • PETIMRI, PSAPD, Spatial distortion correction, Crystal identification

ASJC Scopus subject areas

  • Radiation
  • Nuclear and High Energy Physics
  • Radiology Nuclear Medicine and imaging

Cite this

Spatial distortion correction and crystal identification for position-sensitive avalanche photodiode-based PET scanners. / Chaudhari, Abhijit; Joshi, Anand A.; Wu, Yibao; Leahy, Richard M.; Cherry, Simon R; Badawi, Ramsey D.

IEEE Nuclear Science Symposium Conference Record. 2008. p. 5045-5052 4774373.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Chaudhari, A, Joshi, AA, Wu, Y, Leahy, RM, Cherry, SR & Badawi, RD 2008, Spatial distortion correction and crystal identification for position-sensitive avalanche photodiode-based PET scanners. in IEEE Nuclear Science Symposium Conference Record., 4774373, pp. 5045-5052, 2008 IEEE Nuclear Science Symposium Conference Record, NSS/MIC 2008, Dresden, Germany, 10/19/08. https://doi.org/10.1109/NSSMIC.2008.4774373
Chaudhari, Abhijit ; Joshi, Anand A. ; Wu, Yibao ; Leahy, Richard M. ; Cherry, Simon R ; Badawi, Ramsey D. / Spatial distortion correction and crystal identification for position-sensitive avalanche photodiode-based PET scanners. IEEE Nuclear Science Symposium Conference Record. 2008. pp. 5045-5052
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