Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system

Navid Zeraatkar, Salar Sajedi, Mohammad Hossein Farahani, Hossein Arabi, Saeed Sarkar, Pardis Ghafarian, Arman Rahmim, Mohammad Reza Ay

Research output: Contribution to journalArticle

Abstract

The small-animal High-Resolution SPECT (HiReSPECT) is a dedicated dual-head gamma camera recently designed and developed in our laboratory for imaging of murine models. Each detector is composed of an array of 1.2×1.2mm2 (pitch) pixelated CsI(Na) crystals. Two position-sensitive photomultiplier tubes (H8500) are coupled to each head's crystal. In this paper, we report on a resolution-recovery-embedded image reconstruction code applicable to the system and present the experimental results achieved using different phantoms and mouse scans. Collimator-detector response functions (CDRFs) were measured via a pixel-driven method using capillary sources at finite distances from the head within the field of view (FOV). CDRFs were then fitted by independent Gaussian functions. Thereafter, linear interpolations were applied to the standard deviation (σ) values of the fitted Gaussians, yielding a continuous map of CDRF at varying distances from the head. A rotation-based maximum-likelihood expectation maximization (MLEM) method was used for reconstruction. A fast rotation algorithm was developed to rotate the image matrix according to the desired angle by means of pre-generated rotation maps. The experiments demonstrated improved resolution utilizing our resolution-recovery-embedded image reconstruction. While the full-width at half-maximum (FWHM) radial and tangential resolution measurements of the system were over 2mm in nearly all positions within the FOV without resolution recovery, reaching around 2.5mm in some locations, they fell below 1.8mm everywhere within the FOV using the resolution-recovery algorithm. The noise performance of the system was also acceptable; the standard deviation of the average counts per voxel in the reconstructed images was 6.6% and 8.3% without and with resolution recovery, respectively.

Original languageEnglish (US)
Pages (from-to)774-781
Number of pages8
JournalPhysica Medica
Volume30
Issue number7
DOIs
StatePublished - Nov 1 2014

Fingerprint

Computer-Assisted Image Processing
image reconstruction
Single-Photon Emission-Computed Tomography
animals
recovery
Head
high resolution
collimators
field of view
detectors
Gamma Cameras
standard deviation
Noise
photomultiplier tubes
crystals
interpolation
mice
pixels
cameras
matrices

Keywords

  • H8500
  • HiReSPECT
  • Parallel-hole
  • Resolution recovery
  • Small-animal
  • SPECT

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging
  • Physics and Astronomy(all)
  • Medicine(all)

Cite this

Zeraatkar, N., Sajedi, S., Farahani, M. H., Arabi, H., Sarkar, S., Ghafarian, P., ... Ay, M. R. (2014). Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system. Physica Medica, 30(7), 774-781. https://doi.org/10.1016/j.ejmp.2014.05.013

Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system. / Zeraatkar, Navid; Sajedi, Salar; Farahani, Mohammad Hossein; Arabi, Hossein; Sarkar, Saeed; Ghafarian, Pardis; Rahmim, Arman; Ay, Mohammad Reza.

In: Physica Medica, Vol. 30, No. 7, 01.11.2014, p. 774-781.

Research output: Contribution to journalArticle

Zeraatkar, N, Sajedi, S, Farahani, MH, Arabi, H, Sarkar, S, Ghafarian, P, Rahmim, A & Ay, MR 2014, 'Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system', Physica Medica, vol. 30, no. 7, pp. 774-781. https://doi.org/10.1016/j.ejmp.2014.05.013
Zeraatkar N, Sajedi S, Farahani MH, Arabi H, Sarkar S, Ghafarian P et al. Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system. Physica Medica. 2014 Nov 1;30(7):774-781. https://doi.org/10.1016/j.ejmp.2014.05.013
Zeraatkar, Navid ; Sajedi, Salar ; Farahani, Mohammad Hossein ; Arabi, Hossein ; Sarkar, Saeed ; Ghafarian, Pardis ; Rahmim, Arman ; Ay, Mohammad Reza. / Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system. In: Physica Medica. 2014 ; Vol. 30, No. 7. pp. 774-781.
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