Evaluation of spatial resolution of a PET scanner through the simulation and experimental measurement of the recovery coefficient

Prieto, Elena; Martí-Climent, Josep M.; Arbizu, Javier; Garrastachu, Puy; Domínguez, I.; Quincoces, Gemma; García-Velloso, María José; Lecumberri, Pablo; Gómez, Marisol; Richter, José A.

doi:10.1016/j.compbiomed.2009.11.002

Cited by 26 publications

(26 citation statements)

References 8 publications

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“…As a prerequisite for treatment initiation, all patients had to demonstrate sufficient uptake in pre-therapeutic SSTR-PET computed tomography (CT) [18,19], i.e., lesional uptake higher than physiological liver uptake [21] [22][23][24]. All data was reconstructed using iterative algorithms implemented by the manufacturer and depending on the routine protocol of the different medical centers.…”

Section: Pet/ct Imaging Imaging Interpretationmentioning

confidence: 99%

Pre-therapy Somatostatin Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy

et al. 2018

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Purpose: Early identification of aggressive disease could improve decision support in pancreatic neuroendocrine tumor (pNET) patients prior to peptide receptor radionuclide therapy (PRRT). The prognostic value of intratumoral textural features (TF) determined by baseline somatostatin receptor (SSTR)-positron emission tomography (PET) before PRRT was analyzed. Procedures: Thirty-one patients with G1/G2 pNET were enrolled (G2, n = 23/31). Prior to PRRT with [ 177 Lu]DOTATATE (mean, 3.6 cycles), baseline SSTR-PET computed tomography was performed. By segmentation of 162 (median per patient, 5) metastases, intratumoral TF were computed. The impact of conventional PET parameters (SUV mean/max ), imaging-based TF, and clinical parameters (Ki67, CgA) for prediction of both progression-free survival (PFS) and overall survival (OS) after PRRT were evaluated. Correspondence to: Ralph Bundschuh; e-mail: ralph.bundschuh@ukbonn.deResults: Within a median follow-up of 3.7 years, tumor progression was detected in 21 patients (median, 1.5 years) and 13/31 deceased (median, 1.9 years). In ROC analysis, the TF entropy, reflecting derangement on a voxel-by-voxel level, demonstrated predictive capability for OS (cutoff = 6.7, AUC = 0.71, p = 0.02). Of note, increasing entropy could predict a longer survival (9 6.7, OS = 2.5 years, 17/31), whereas less voxel-based derangement portended inferior outcome (G 6.7, OS = 1.9 years, 14/31). These findings were supported in a G2 subanalysis (9 6.9, OS = 2.8 years, 9/23 vs. G 6.9, OS = 1.9 years, 14/23). Kaplan-Meier analysis revealed a significant distinction between high-and low-risk groups using entropy (n = 31, p G 0.05). For those patients below the ROC-derived threshold, the relative risk of death after PRRT was 2.73 (n = 31, p = 0.04). Ki67 was negatively associated with PFS (p = 0.002); however, SUV mean/max failed in prognostication (n.s.). Conclusions: In contrast to conventional PET parameters, assessment of intratumoral heterogeneity demonstrated superior prognostic performance in pNET patients undergoing PRRT. This novel PET-based strategy of outcome prediction prior to PRRT might be useful for patient risk stratification.

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Section: Pet/ct Imaging Imaging Interpretationmentioning

confidence: 99%

Pre-therapy Somatostatin Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy

et al. 2018

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“…However, given the absence of an effect of this variable in the statistical analyses and the strong test-retest reliability of DERS with a 4 – 8 week interval (Gratz and Roemer, 2004), this should not affect the results. Another limitation relates to the low spatial resolution of PET (Prieto et al, 2010), which generally cannot distinguish between subnuclei of the amygdala that serve different functions and vary in the relative densities of D2 and D3 receptors (Alleweireldt et al, 2006; Grace and Rosenkranz, 2002; Rosenkranz and Grace, 1999). In addition, [ 18 F]fallypride has almost equal affinity for D2 and D3 receptors (Jerjian et al, 2010), preventing a separate assessment of either receptor subtype.…”

Section: Discussionmentioning

confidence: 99%

Emotion dysregulation and amygdala dopamine D2-type receptor availability in methamphetamine users

Okita

Ghahremani

Payer

et al. 2016

Drug and Alcohol Dependence

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Background Individuals who use methamphetamine chronically exhibit emotional and dopaminergic neurochemical deficits. Although the amygdala has an important role in emotion processing and receives dopaminergic innervation, little is known about how dopamine transmission in this region contributes to emotion regulation. This investigation aimed to evaluate emotion regulation in subjects who met DSM-IV criteria for methamphetamine dependence, and to test for a relationship between self-reports of difficulty in emotion regulation and D2-type dopamine receptor availability in the amygdala. Method Ninety-four methamphetamine-using and 102 healthy-control subjects completed the Difficulties in Emotion Regulation Scale (DERS); 33 of those who used methamphetamine completed the Addiction Severity Index (ASI). A subset of 27 methamphetamine-group and 20 control-group subjects completed positron emission tomography with [18F]fallypride to assay amygdala D2-type dopamine receptor availability, measured as binding potential (BPND). Results The methamphetamine group scored higher than the control group on the DERS total score (p < 0.001), with DERS total score positively correlated with the Drug Composite Score on the ASI (p = 0.02) in the methamphetamine group. The DERS total score was positively correlated with amygdala BPND in both groups and the combined group of participants (combined: r = 0.331, p = 0.02), and the groups did not differ in this relationship. Conclusion These findings highlight problems with emotion regulation linked to methamphetamine use, possibly contributing to personal and interpersonal behavioral problems. They also suggest that D2-type dopamine receptors in the amygdala contribute to emotion regulation in both healthy and methamphetamine-using subjects.

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“…As expected, it can be concluded that FBP is inferior to IT with regard to image quality, as has been extensively reported previously (25,26). Additionally, the reduction of equivalent iterations, that is, the product of iterations and subsets (IT-4), softens the image on the one hand but leads to increased blurring and therefore reduced image quality on the other hand (27)(28)(29). IT-1 to IT-3 do not differ with regard to image quality; therefore, we assume that zoom and matrix do not directly influence the image quality.…”

Section: Comparison Of 131 I Raiu and 124 I Raiumentioning

confidence: 49%

Assessment of Minimum ¹²⁴I Activity Required in Uptake Measurements Before Radioiodine Therapy for Benign Thyroid Diseases

et al. 2016

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This study aimed to assess a hypothetical minimum administered activity of 124 I required to achieve comparability between pretherapeutic radioiodine uptake (RAIU) measurements by 124 I PET/CT and by 131 I RAIU probe, the clinical standard. In addition, the impact of different reconstruction algorithms on 124 I RAIU and the evaluation of pixel noise as a parameter for image quality were investigated. Methods: Different scan durations were simulated by different reconstruction intervals of 600-s list-mode PET datasets (including 15 intervals up to 600 s and 5 different reconstruction algorithms: filtered-backprojection and 4 iterative techniques) acquired 30 h after administration of 1 MBq of 124 I. The Bland-Altman method was used to compare mean 124 I RAIU levels versus mean 3-MBq 131 I RAIU levels (clinical standard). The data of 37 patients with benign thyroid diseases were assessed. The impact of different reconstruction lengths on pixel noise was investigated for all 5 of the 124 I PET reconstruction algorithms. A hypothetical minimum activity was sought by means of a proportion equation, considering that the length of a reconstruction interval equates to a hypothetical activity. Results: Mean 124 I RAIU and 131 I RAIU already showed high levels of agreement for reconstruction intervals of as short as 10 s, corresponding to a hypothetical minimum activity of 0.017 MBq of 124 I. The iterative algorithms proved generally superior to the filteredbackprojection algorithm. 124 I RAIU showed a trend toward higher levels than 131 I RAIU if the influence of retrosternal tissue was not considered, which was proven to be the cause of a slight overestimation by 124 I RAIU measurement. A hypothetical minimum activity of 0.5 MBq of 124 I obtained with iterative reconstruction appeared sufficient both visually and with regard to pixel noise. Conclusion: This study confirms the potential of 124 I RAIU measurement as an alternative method for 131 I RAIU measurement in benign thyroid disease and suggests that reducing the administered activity is an option. CT information is particularly important in cases of retrosternal expansion. The results are relevant because 124 I PET/CT allows additional diagnostic means, that is, the possibility of performing fusion imaging with ultrasound. 124 I PET/CT might be an alternative, especially when hybrid 123 I SPECT/CT is not available.

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Evaluation of spatial resolution of a PET scanner through the simulation and experimental measurement of the recovery coefficient

Abstract: Measurement of the recovery coefficient provides an assessment of tomographic spatial resolution, particularly in clinical studies conditions.

Cited by 26 publications

References 8 publications

Pre-therapy Somatostatin Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy

Pre-therapy Somatostatin Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy

Emotion dysregulation and amygdala dopamine D2-type receptor availability in methamphetamine users

Assessment of Minimum ¹²⁴I Activity Required in Uptake Measurements Before Radioiodine Therapy for Benign Thyroid Diseases

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Evaluation of spatial resolution of a PET scanner through the simulation and experimental measurement of the recovery coefficient

Abstract: Measurement of the recovery coefficient provides an assessment of tomographic spatial resolution, particularly in clinical studies conditions.

Cited by 26 publications

References 8 publications

Pre-therapy Somatostatin Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy

Pre-therapy Somatostatin Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy

Emotion dysregulation and amygdala dopamine D2-type receptor availability in methamphetamine users

Assessment of Minimum 124I Activity Required in Uptake Measurements Before Radioiodine Therapy for Benign Thyroid Diseases

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Product

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About

Assessment of Minimum ¹²⁴I Activity Required in Uptake Measurements Before Radioiodine Therapy for Benign Thyroid Diseases