Assessment of collimators in radium-223 imaging with channelized Hotelling observer: a simulation study

Takahashi, Akihiko; Baba, Shingo; Sasaki, Masayuki

doi:10.1007/s12149-018-1286-4

Cited by 4 publications

(2 citation statements)

References 23 publications

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“…There are reasons to believe that the results published herein could be improved by optimization of the acquisition and reconstruction parameters. There has been some discussion in the literature about the relative benefits of different collimators for 223 Ra imaging (Takahashi et al 2016, Owaki et al 2017, Takahashi et al 2018. Given the high energy component of the photon emission spectrum of 223 Ra, it might be suspected that a high-energy collimator could be superior for quantification since it suppresses hard-to-model effects such as penetration.…”

Section: Spheresmentioning

confidence: 99%

Feasibility and limitations of quantitative SPECT for ²²³Ra

2020

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The aim of this paper is to investigate the feasibility and limitations of activity-concentration estimation for 223Ra using SPECT. Phantom measurements are performed using spheres (volumes 5.5 mL to 26.4 mL, concentrations 1.6 kBq mL−1 to 4.5 kBq mL−1). Furthermore, SPECT projections are simulated using the SIMIND Monte Carlo program for two geometries, one similar to the physical phantom and the other being an anthropomorphic phantom with added lesions (volumes 34 mL to 100 mL, concentrations 0.5 kBq mL−1 to 4 kBq mL−1). Medium-energy and high-energy collimators, 60 projections with 55 s per projection and a 20% energy window at 82 keV are employed. For the Monte Carlo simulated images, Poisson-distributed noise is added in ten noise realizations. Reconstruction is performed (OS-EM, 40 iterations, 6 subsets) employing compensation for attenuation, scatter, and collimator-detector response. The estimated concentrations in the anthropomorphic phantom are also corrected using recovery coefficients. Errors for the largest sphere in the physical phantom range from −25% to −34% for the medium-energy collimator and larger deviations for smaller spheres. Corresponding results for the high-energy collimator are −15% to −31%. The corresponding Monte Carlo simulations show standard deviations of a few percentage points. For the anthropomorphic phantom, before application of recovery coefficients the bias ranges from −16% to −46% (medium-energy collimator) and −10% to −28% (high-energy collimator), with standard deviations of 2% to 14% and 1% to 16%. After the application of recovery coefficients, the biases range from −3% to −35% (medium energy collimator) and from 0% to −18%. The errors decrease with increasing concentrations. Activity-concentration estimation of 223Ra with SPECT is feasible, but problems with repeatability need to be further studied.

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Section: Spheresmentioning

confidence: 99%

Feasibility and limitations of quantitative SPECT for ²²³Ra

2020

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“…Image noise (N), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated according to the methods recommended by the National Electrical Manufacturers Association ( 13 ).…”

Section: Methodsmentioning

confidence: 99%

Image quality and evaluation ability of magnetic resonance imaging techniques for thyroid-associated ophthalmopathy: Dixon fat-suppression technique vs. spectral attenuated inversion recovery

et al. 2023

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PurposeWe aimed to compare two magnetic resonance imaging (MRI) techniques, Dixon and spectral attenuated inversion recovery (SPAIR) fat-suppression, in terms of image quality and suitability for evaluating thyroid-associated ophthalmopathy (TAO) lesion characteristics.MethodsThis cross-sectional, retrospective study involved 70 patients with TAO (140 eyes) who underwent orbital coronal MRI examinations, including Dixon-transverse relaxation (T2)-weighted imaging (T2WI) and SPAIR-T2WI, between 2020 and 2022. We compared the fat-suppression quality and artifacts, noise (N), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), signal intensity ratio (SIR) of extraocular muscles (SIR-EOM) and lacrimal glands (SIR-LG), and TAO activity evaluation efficiency.ResultsDixon-T2WI showed a higher frequency of better subjective image quality and suitability for evaluating the characteristics of TAO lesions (65.7% vs. 14.3%) than SPAIR-T2WI. Fat-suppression quality and artifact scores were lower for Dixon-T2WI than for SPAIR-T2WI (p < 0.001). The N, SNR, and CNR values, EOM-SIR, and LG-SIR were higher for orbital coronal Dixon-T2WI than for SPAIR-T2WI (all p < 0.001). Clinical activity scores (CASs) showed positive correlations with SIR. The correlation between EOM-SIR and LG-SIR of orbital coronal Dixon-T2WI with CAS was higher than that of SPAIR-T2WI (0.590 vs. 0.493, all p < 0.001; 0.340 vs. 0.295, all p < 0.01). EOM-SIR and LG-SIR of Dixon-T2WI yielded a higher area under the curve than SPAIR-T2WI for evaluating TAO activity (0.865 vs. 0.760, p < 0.001; 0.695 vs. 0.617, p = 0.017).ConclusionDixon-T2WI yields higher image quality than SPAIR-T2WI. Furthermore, it has a stronger ability to evaluate TAO inflammation than SPAIR, with higher sensitivity and specificity in active TAO staging.

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Monte Carlo simulation study to explore optimum conditions for Astatine-211 SPECT

Takahashi

Kajiya

Baba

et al. 2023

Radiol Phys Technol

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Assessment of collimators in radium-223 imaging with channelized Hotelling observer: a simulation study

Cited by 4 publications

References 23 publications

Feasibility and limitations of quantitative SPECT for ²²³Ra

Feasibility and limitations of quantitative SPECT for ²²³Ra

Image quality and evaluation ability of magnetic resonance imaging techniques for thyroid-associated ophthalmopathy: Dixon fat-suppression technique vs. spectral attenuated inversion recovery

Monte Carlo simulation study to explore optimum conditions for Astatine-211 SPECT

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Assessment of collimators in radium-223 imaging with channelized Hotelling observer: a simulation study

Cited by 4 publications

References 23 publications

Feasibility and limitations of quantitative SPECT for 223Ra

Feasibility and limitations of quantitative SPECT for 223Ra

Image quality and evaluation ability of magnetic resonance imaging techniques for thyroid-associated ophthalmopathy: Dixon fat-suppression technique vs. spectral attenuated inversion recovery

Monte Carlo simulation study to explore optimum conditions for Astatine-211 SPECT

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Product

Resources

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Feasibility and limitations of quantitative SPECT for ²²³Ra

Feasibility and limitations of quantitative SPECT for ²²³Ra