Computationally efficient collimator-detector response compensation in high energy SPECT using 1D convolutions and rotations.

Autor:	Polson LA; The University of British Columbia, 675 West 10th Avenue, Vancouver, British Columbia, V6T 1Z4, CANADA., Esquinas P; Molecular Oncology, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia, V5Z 1L3, CANADA., Kurkowska S; Integrative Oncology, BC Cancer Research Centre, 675 W 10th Ave, Vancouver, British Columbia, V5Z 1L3, CANADA., Li C; Physics, The University of British Columbia, 6224 Agricultural Rd, Vancouver, British Columbia, V6T 1Z4, CANADA., Sheikhzadeh P; Tehran University of Medical Sciences, District 6, Pour Sina St, Tehran, 1416753955, Iran (the Islamic Republic of)., Abbasi M; Medical Physics, Vali-Asr Hospital, Tehran University of Medical Sciences, Tehran 1419731351, Iran, Tehran, 1419731351, Iran (the Islamic Republic of)., Farzenefar S; Vali-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran., Tehran, Tehran, 1416753955, Iran (the Islamic Republic of)., Mirabedian S; Tehran University of Medical Sciences, Vali-Asr Hospital, Tehran, Tehran, 1416753955, Iran (the Islamic Republic of)., Uribe CF; Molecular Oncology, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia, V5Z 1L3, CANADA., Rahmim A; Radiology and Physics, The University of British Columbia, 6224 Agricultural Rd, Vancouver, British Columbia, V6T 1Z4, CANADA.
Jazyk:	angličtina
Zdroj:	Physics in medicine and biology [Phys Med Biol] 2024 Dec 18. Date of Electronic Publication: 2024 Dec 18.
DOI:	10.1088/1361-6560/ada10a
Abstrakt:	Objective: Modeling of the collimator-detector response (CDR) in SPECT reconstruction enables improved resolution and accuracy, and is thus important for quantitative imaging applications such as dosimetry. The implementation of CDR modeling, however, can become a computational bottleneck when there are substantial components of septal penetration and scatter in the acquired data, since a direct convolution-based approach requires large 2D kernels. This work proposes a 1D convolution and rotation-based CDR model that reduces reconstruction times but maintains consistency with models that employ 2D convolutions. To enable open-source development and use of these models in image reconstruction, we release a SPECTPSFToolbox repository for the PyTomography project on GitHub. Approach: A 1D/rotation-based CDR model was formulated and subsequently fit to Monte Carlo point source data representative of Lu-177, I-131, and Ac-225 imaging. Computation times of (i) the proposed 1D/rotation-based model and (ii) a traditional model that uses 2D convolutions were compared for typical SPECT matrix sizes. Both CDR models were then used in the reconstruction of Monte Carlo, physical phantom, and patient data; the models were compared by quantifying total counts in hot regions of interest (ROIs) and activity contrast between hot ROIs and background regions. Results: For typical matrix sizes in SPECT reconstruction, application of the 1D/rotation-based model provides a two-fold computational speed-up over the 2D model when running on GPU. Only small differences between the 1D/rotation-based and 2D models (order of 1%) were obtained for count and contrast quantification in select ROIs. Significance: A technique for CDR modeling in SPECT was proposed that (i) significantly speeds up reconstruction times, and (ii) yields nearly identical reconstructions to traditional 2D convolution based CDR techniques. The released toolbox will permit open-source development of similar models for different isotopes and collimators. (Creative Commons Attribution license.)
Databáze:	MEDLINE
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