Validation of GATE simulations of the &lt;sup&gt;176&lt;/sup&gt;Lu intrinsic activity in LSO detectors

McIntosh, Bryan; Goertzen, Andrew L.

doi:10.1109/nssmic.2009.5401776

Cited by 2 publications

(3 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the magnitude of the signal background resulting from natural 176 Lu in LSO-based scanners has been characterized [8–10], there is only one published study to our knowledge that examines the effect of 176 Lu background on measurements of weak sources in the field of view of a preclinical scanner [11]. We know of no previously published studies that have compared the performance of clinical scanners based upon the most common PET detector materials LSO and BGO in this low-activity range.…”

Section: Introductionmentioning

confidence: 99%

Performance and limitations of positron emission tomography (PET) scanners for imaging very low activity sources

et al. 2014

View full text Add to dashboard Cite

Emerging applications for positron emission tomography (PET) may require the ability to image very low activity source distributions in the body. The performance of clinical PET scanners in the regime where activity in the field of view is <1 MBq has not previously been explored. In this study, we compared the counting rate performance of two clinical PET/CT scanners, the Siemens Biograph Reveal 16 scanner which is based on lutetium oxyorthosilicate (LSO) detectors and the GE Discovery-ST scanner which is based on bismuth germanate (BGO) detectors using a modified National Electrical Manufacturers Association (NEMA) NU 2-2007 protocol. Across the activity range studied (2-100 kBq/mL in a 5.5 mL line source in the NEMA scatter phantom), the BGO-based scanner significantly outperformed the LSO-based scanner. This was largely due to the effect of background counts emanating from naturally occurring but radioactive 176Lu within the LSO detector material, which dominates the observed counting rate at the lowest activities. Increasing the lower energy threshold from 350 keV to 425 keV in an attempt to reduce this background did not significantly improve the measured NECR performance. The measured singles rate due to 176Lu emissions within the scanner energy window was also found to be dependent on temperature, and to be affected by the operation of CT component, making approaches to correct or compensate for the background more challenging. We conclude that for PET studies in a very low activity range, BGO-based scanners are likely to have better performance because of the lack of significant background.

show abstract

Section: Introductionmentioning

confidence: 99%

Performance and limitations of positron emission tomography (PET) scanners for imaging very low activity sources

et al. 2014

View full text Add to dashboard Cite

show abstract

“…This intrinsic activity within the LYSO crystals was simulated as a 176 Lu ion source, which is the most accurate method to simulate the radioactive decay 44 . The intrinsic activity source encompassed the whole scanner, and the activity (ion source) was confined to the LYSO scintillation crystals 53 . To quantify the impact of intrinsic activities, scanner performance was simulated with and without intrinsic activities.…”

Section: Methodsmentioning

confidence: 99%

“…44 The intrinsic activity source encompassed the whole scanner, and the activity (ion source) was confined to the LYSO scintillation crystals. 53 To quantify the impact of intrinsic activities, scanner performance was simulated with and without intrinsic activities. The count rate curves for DMI four-ring configuration with and without 176 Lu background intrinsic activities are generated for visual inspection, and the ratio of NECR with and without intrinsic activity is estimated.…”

Section: Intrinsic Activity In Lyso Crystalsmentioning

confidence: 99%

Monte Carlo evaluation of hypothetical long axial field‐of‐view PET scanner using GE Discovery MI PET front‐end architecture

et al. 2022

View full text Add to dashboard Cite

The development of total-body PET scanners is of growing interest in the PET community. Investigation into the imaging properties of a hypothetical extended axial field-of -view (AFOV) GE Healthcare SiPM-based Discovery MI (DMI) system architecture has not yet been performed.In this work,we assessed its potential as a whole-body scanner using Monte Carlo simulations. The aim of this work was to (1) develop and validate a Monte Carlo model of a fourring scanner and (2) extend its AFOV up to 2 m to evaluate performance gain through NEMA-based evaluation. Methods: The DMI four-ring geometry and its pulse digitization scheme were modeled within the GATE Monte Carlo platform using published literature. The GATE scanner model was validated by comparing results against published NEMA performance measurements. Following the validation of the four-ring model, the model was extended to simulate 8-, 20-, 30-, and 40-ring systems. Spatial resolution, sensitivity, NECR, and scatter fraction were characterized with modified NEMA NU-2 2018 standards; however, the image quality measurements were not acquired due to computational limitations. Spatial resolutions were simulated for all scanner ring configurations using point sources to examine the effects of parallax errors. NEMA count rates were estimated using a standard 70 cm scatter phantom and an extended version of scatter phantom of length 200 cm with (1-800) MBq of 18 F for all scanners. Sensitivity was evaluated using NEMA methods with a 70 cm standard and a 200 cm long line source. Results:The average FWHM of the radial/tangential/axial spatial resolution reconstructed with filtered back-projection at 1 and 10 cm from the scanner center were 3.94/4.10/4.41 mm and 5.29/4.89/5.90 mm for the four-ring scanner. Sensitivity was determined to be 14.86 cps/kBq at the center of the FOV for the four-ring scanner using a 70 cm line source. Sensitivity enhancement up to 21-fold and 60-fold were observed for 1 and 2 m AFOV scanners compared to four-ring scanner using a 200 cm long line source. Spatial resolution simulations in a 2 m AFOV scanner suggest a maximum degradation of ∼23.8% in the axial resolution compared to the four-ring scanner. However, the transverse resolution was found to be relatively constant when increasing the axial acceptance angle up to ±70 • . The peak NECR was 212.92 kcps at 22.70 kBq/ml with a scatter fraction of 38.9% for a four-ring scanner with a 70 cm scatter phantom. Comparison of peak NECR using the 200 cm long scatter phantom relative to the four-ring scanner resulted in a NECR gain of 15 for the 20-ring and 28 for the 40-ring geometry. Spatial resolution, sensitivity, and scatter fraction showed an agreement within ∼7% compared with published measured values.

show abstract

Validation of GATE simulations of the <sup>176</sup>Lu intrinsic activity in LSO detectors

Cited by 2 publications

References 5 publications

Performance and limitations of positron emission tomography (PET) scanners for imaging very low activity sources

Performance and limitations of positron emission tomography (PET) scanners for imaging very low activity sources

Monte Carlo evaluation of hypothetical long axial field‐of‐view PET scanner using GE Discovery MI PET front‐end architecture

Contact Info

Product

Resources

About