scholarly journals Feasibility of late acquisition [68Ga]Ga-PSMA-11 PET/CT using a long axial field-of-view PET/CT scanner for the diagnosis of recurrent prostate cancer—first clinical experiences

2021 ◽  
Author(s):  
Ian Alberts ◽  
George Prenosil ◽  
Clemens Mingels ◽  
Karl Peter Bohn ◽  
Marco Viscione ◽  
...  
Keyword(s):  
Image Quality ◽  
Case Series ◽  
Likert Scale ◽  
Target Lesion ◽  
Field Of View ◽  
Ct Scanner ◽  
Axial Field ◽  
Retrospective Case ◽  
Imaging Quality ◽  
Pet Ct

Abstract Purpose While acquisition of images in [68 Ga]Ga-PSMA-11 following longer uptake times can improve lesion uptake and contrast, resultant imaging quality and count statistics are limited by the isotope’s half-life (68 min). Here, we present a series of cases demonstrating that when performed using a long axial field-of-view (LAFOV) PET/CT system, late imaging is feasible and can even provide improved image quality compared to regular acquisitions. Methods In this retrospective case series, we report our initial experiences with 10 patients who underwent standard imaging at 1 h p.i. following administration of 192 ± 36 MBq [68 Ga]Ga-PSMA-11 with additional late imaging performed at 4 h p.i. Images were acquired in a single bed position for 6 min at 1 h p.i. and 16 min p.i. at 4 h p.i. using a LAFOV scanner (106 cm axial FOV). Two experienced nuclear medicine physicians reviewed all scans in consensus and evaluated overall image quality (5-point Likert scale), lesion uptake in terms of standardised uptake values (SUV), tumour to background ratio (TBR) and target-lesion signal to background noise (SNR). Results Subjective image quality as rated on a 5-point Likert scale was only modestly lower for late acquisitions (4.2/5 at 4 h p.i.; 5/5 1 h p.i.), TBR was significantly improved (4 h: 3.41 vs 1 h: 1.93, p < 0.001) and SNR was improved with borderline significance (4 h: 33.02 vs 1 h: 24.80, p = 0.062) at later imaging. Images were obtained with total acquisition times comparable to routine examinations on standard axial FOV scanners. Conclusion Late acquisition in tandem with a LAFOV PET/CT resulted in improvements in TBR and SNR and was associated with only modest impairment in subjective visual imaging quality. These data show that later acquisition times for [68 Ga]Ga-PSMA-11 may be preferable when performed on LAFOV systems.

scholarly journals Clinical performance of long axial field of view PET/CT: a head-to-head intra-individual comparison of the Biograph Vision Quadra with the Biograph Vision PET/CT

2021 ◽  
Author(s):  
Ian Alberts ◽  
Jan-Niklas Hünermund ◽  
George Prenosil ◽  
Clemens Mingels ◽  
Karl Peter Bohn ◽  
...  
Keyword(s):  
Image Quality ◽  
Low Dose ◽  
Clinical Performance ◽  
Visual Image ◽  
Target Lesion ◽  
Field Of View ◽  
List Mode ◽  
Axial Field ◽  
Individual Comparison ◽  
Pet Ct

Abstract Purpose To investigate the performance of the new long axial field-of-view (LAFOV) Biograph Vision Quadra PET/CT and a standard axial field-of-view (SAFOV) Biograph Vision 600 PET/CT (both: Siemens Healthineers) system using an intra-patient comparison. Methods Forty-four patients undergoing routine oncological PET/CT were prospectively included and underwent a same-day dual-scanning protocol following a single administration of either 18F-FDG (n = 20), 18F-PSMA-1007 (n = 16) or 68Ga-DOTA-TOC (n = 8). Half the patients first received a clinically routine examination on the SAFOV (FOVaxial 26.3 cm) in continuous bed motion and then immediately afterwards on the LAFOV system (10-min acquisition in list mode, FOVaxial 106 cm); the second half underwent scanning in the reverse order. Comparisons between the LAFOV at different emulated scan times (by rebinning list mode data) and the SAFOV were made for target lesion integral activity, signal to noise (SNR), target lesion to background ratio (TBR) and visual image quality. Results Equivalent target lesion integral activity to the SAFOV acquisitions (16-min duration for a 106 cm FOV) were obtained on the LAFOV in 1.63 ± 0.19 min (mean ± standard error). Equivalent SNR was obtained by 1.82 ± 1.00 min LAFOV acquisitions. No statistically significant differences (p > 0.05) in TBR were observed even for 0.5 min LAFOV examinations. Subjective image quality rated by two physicians confirmed the 10 min LAFOV to be of the highest quality, with equivalence between the LAFOV and the SAFOV at 1.8 ± 0.85 min. By analogy, if the LAFOV scans were maintained at 10 min, proportional reductions in applied radiopharmaceutical could obtain equivalent lesion integral activity for activities under 40 MBq and equivalent doses for the PET component of <1 mSv. Conclusion Improved image quality, lesion quantification and SNR resulting from higher sensitivity were demonstrated for an LAFOV system in a head-to-head comparison under clinical conditions. The LAFOV system could deliver images of comparable quality and lesion quantification in under 2 min, compared to routine SAFOV acquisition (16 min for equivalent FOV coverage). Alternatively, the LAFOV system could allow for low-dose examination protocols. Shorter LAFOV acquisitions (0.5 min), while of lower visual quality and SNR, were of adequate quality with respect to target lesion identification, suggesting that ultra-fast or low-dose acquisitions can be acceptable in selected settings.

scholarly journals The effect of modern PET technology and techniques on the EANM paediatric dosage card

2021 ◽  
Author(s):  
John Dickson ◽  
Uta Eberlein ◽  
Michael Lassmann
Keyword(s):  
Image Quality ◽  
Field Of View ◽  
Published Data ◽  
Axial Field ◽  
Short Article ◽  
Pet Ct ◽  
Class B ◽  
Total Body ◽  
Bed Position ◽  
Pet Scanners

Abstract Aim Recent advancements in PET technology have brought with it significant improvements in PET performance and image quality. In particular, the extension of the axial field of view of PET systems, and the introduction of semiconductor technology into the PET detector, initially for PET/MR, and more recently available long-field-of-view PET/CT systems (≥ 25 cm) have brought a step change improvement in the sensitivity of PET scanners. Given the requirement to limit paediatric doses, this increase in sensitivity is extremely welcome for the imaging of children and young people. This is even more relevant with PET/MR, where the lack of CT exposures brings further dose reduction benefits to this population. In this short article, we give some details around the benefits around new PET technology including PET/MR and its implications on the EANM paediatric dosage card. Material and methods  Reflecting on EANM adult guidance on injected activities, and making reference to bed overlap and the concept of MBq.min bed−1 kg−1, we use published data on image quality from PET/MR systems to update the paediatric dosage card for PET/MR and extended axial field of view (≥ 25 cm) PET/CT systems. However, this communication does not cover the expansion of paediatric dosing for the half-body and total-body scanners that have recently come to market. Results In analogy to the existing EANM dosage card, new parameters for the EANM paediatric dosage card were developed (class B, baseline value: 10.7 MBq, minimum recommended activity 10 MBq). The recommended administered activities for the systems considered in this communication range from 11 MBq [18F]FDG for a child with a weight of 3 kg to 149 MBq [18F]FDG for a paediatric patient weight of 68 kg, assuming a scan of 3 min per bed position. The mean effective dose over all ages (1 year and older) is 2.85 mSv. Conclusion With this, recommendations for paediatric dosing are given for systems that have not been considered previously.

scholarly journals Performance evaluation of the uEXPLORER Total-body PET/CT scanner based on NEMA NU 2-2018 with additional tests to characterize long axial field-of-view PET scanners

2020 ◽  
pp. jnumed.120.250597 ◽  
Author(s):  
Benjamin A. Spencer ◽  
Eric Berg ◽  
Jeffrey P. Schmall ◽  
Negar Omidvari ◽  
Edwin K. Leung ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Field Of View ◽  
Ct Scanner ◽  
Axial Field ◽  
Pet Ct ◽  
Total Body ◽  
Pet Scanners

The effect of activity outside the field of view on image quality for a 3D LSO-based whole body PET/CT scanner

2009 ◽  
Vol 54 (19) ◽  
pp. 5861-5872 ◽  
Author(s):  
R Matheoud ◽  
C Secco ◽  
P Della Monica ◽  
L Leva ◽  
G Sacchetti ◽  
...  
Keyword(s):  
Image Quality ◽  
Field Of View ◽  
Whole Body ◽  
Ct Scanner ◽  
Pet Ct

Performance Characteristics of a New LSO PET/CT Scanner With Extended Axial Field-of-View and PSF Reconstruction

2009 ◽  
Vol 56 (3) ◽  
pp. 633-639 ◽  
Author(s):  
Bjoern W. Jakoby ◽  
Yanic Bercier ◽  
Charles C. Watson ◽  
Bernard Bendriem ◽  
David W. Townsend
Keyword(s):  
Performance Characteristics ◽  
Field Of View ◽  
Ct Scanner ◽  
Axial Field ◽  
Pet Ct

scholarly journals Evaluation of the Impact of Out-of-Axial FOV Scattering Medium on Random Coincidence Rates on Discovery 690 PET/CT Scanner: A Simulation Study

2020 ◽  
Author(s):  
Mahak Osouli Alamdari ◽  
Pardis Ghafarian ◽  
Parham Geramifar ◽  
Mohammad Reza Ay
Keyword(s):  
Imaging Technique ◽  
Field Of View ◽  
Ct Scanner ◽  
Scattering Medium ◽  
Nuclear Medicine Imaging ◽  
Axial Field ◽  
Random Coincidence ◽  
Positron Emission ◽  
Pet Ct ◽  
The Impact

Purpose: Positron Emission Tomography (PET) imaging is a nuclear medicine imaging technique based on the recording of two photons as coincidence created by positron annihilation. Materials and Methods: PET coincidence events include true and unwanted coincidences (random, scattered, multiple coincidences). We modeled the Discovery 690 (D-690) PET scanner using the GATE simulation tool and estimated the effect of the diameter of the scattering medium out of the Axial Field Of View (AFOV) on the random coincidence rates. Results: The validation results indicated that the average difference between simulated and measured data for sensitivity and scatter fraction tests are 5% and 3%, respectively. Moreover, the results revealed that the increasing diameter of the scattering medium out of the AFOV has a direct effect on the random coincidence rates within the Field Of View (FOV). Conclusion: The study concluded that the presence of a scattering medium near the FOV increases the rate of random coincidences.  

scholarly journals THU0319 DEVELOPMENT AND OUTCOME OF AORTIC COMPLICATIONS DURING TOCILIZUMAB TREATMENT OF GCA AND HISTOPATHOLOGIC EVIDENCE OF RESIDUAL INFLAMMATION-A CASE SERIES.

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 388.2-389
Author(s):  
A. Rubbert-Roth ◽  
P. K. Bode ◽  
T. Langenegger ◽  
C. Pfofe ◽  
T. Neumann ◽  
...  
Keyword(s):  
Structural Changes ◽  
Case Series ◽  
Aortic Aneurysms ◽  
Imaging Data ◽  
Limited Data ◽  
Retrospective Case ◽  
Pet Ct ◽  
Fdg Pet Ct ◽  
Pet Ct Scan

Background:Giant cell arteritis (GCA) may affect the aorta and the large aortic branches and lead to dissections and aortic aneurysms. Tocilizumab (TCZ) treatment has the capacity to control aortic inflammation as has been demonstrated by CRP normalization and imaging data. However, limited data are available on the histopathological findings obtained from patients who underwent surgery because of aortic complications during TCZ treatment.Objectives:We report on 5 patients with aortitis who were treated with TCZ and developed aortic complications.Methods:We describe a retrospective case series of patients with GCA treated with TCZ, who presented in our clinic between 2011 and 2019. Three patients underwent surgery. Histopathologic examination was performed in specimen from all of them.Results:Five female patients were diagnosed with GCA (4/5) or Takaysu arteritis (1/5) involving the aorta, all them diagnosed by MR angiography and/or FDG PET CT scan. Three patients (one with aortic aneurysm, one with dissection) underwent surgery after having been treated with TCZ for seven weeks, nine months and four years, respectively. Imaging before surgery showed remission on MRI and/or PET-CT in all cases. At the time of surgery, all patients showed normalized CRP and ESR values. Histopathological evaluation of the aortic wall revealed infiltrates, consisting predominantly of CD3+CD4+ T cells. Enlargement of pre-existing aneuryms was observed in the other two patients 10 weeks and 4 months after discontinuation of TCZ, respectively. Both patients were not eligible for surgical intervention and died during follow-up.Conclusion:Our case series suggests that during treatment with TCZ, regular imaging is necessary in this patient population to detect development of structural changes such as aneurysms or dissections. Despite treatment, residual inflammation might persist which could contribute to eventual aortic complications.Disclosure of Interests:Andrea Rubbert-Roth Consultant of: Abbvie, BMS, Chugai, Pfizer, Roche, Janssen, Lilly, Sanofi, Amgen, Novartis, Peter Karl Bode: None declared, Thomas Langenegger: None declared, Claudia Pfofe: None declared, Thomas Neumann: None declared, Olaf Chan-Hi Kim: None declared, Johannes von Kempis Consultant of: Roche

scholarly journals Optimizing reconstruction parameters for quantitative 124I-PET in the presence of therapeutic doses of 131I

2021 ◽  
Author(s):  
Louise Fanchon ◽  
Brad Beattie ◽  
Keith Pentlow ◽  
Steven Larson ◽  
John Laurence Humm
Keyword(s):  
Image Quality ◽  
Dead Time ◽  
Activity Level ◽  
Ct Scanner ◽  
Random Coincidence ◽  
Quantitative Pet ◽  
Quantitative Accuracy ◽  
Pet Ct ◽  
Therapeutic Doses ◽  
Pet Detectors

Abstract Purpose To determine the accuracy of quantitative 124I PET imaging in the presence of therapeutic levels of 131I.Material and Methods Multiple PET images were acquired using a NEMA IEC phantom with spheres containing 0.4 MBq/cc of 124I and increasing amount of 131I activity in the phantom background (0 to 3.76 GBq). Acquisitions were performed on a GE Discovery 710 PET/CT scanner. At each 131I activity level two scans were acquired, one with the phantom at the center of the field of view (FOV) and one 11 cm off-center. Images were reconstructed with an ordered subset expectation maximization (OSEM) algorithm using between 1 and 25 iterations of 16 subsets. Results were evaluated visually and by comparing the 124I activity relative to the baseline PET performed in the absence of 131I.Results The presence of 131I within the PET FOV added to the random coincidence rate, to dead-time and to pile-up within the PET detectors. Using our standard clinical reconstruction parameters, the image quality and quantitative accuracy suffered at 131I background activities above 1.4 GBq. However, increasing the number of iterations resulted in dramatic improvements in image quality and quantitative accuracy. Projection space measurements suggest that the dead time corrections implemented on the scanner perform well even at the highest singles count rate tested (52 Mcps).Conclusion This study shows that 124I quantitative PET is feasible in the presence of large amounts of 131I on a GE D710. The high random coincidence fraction slows the reconstruction convergence rate, therefore iterations equivalent to at least 8x16 are recommended.

Impact of flexible body surface coil and patient table on PET quantification and image quality in integrated PET/MR

2014 ◽  
Vol 53 (03) ◽  
pp. 79-87 ◽  
Author(s):  
M. Souvatzoglou ◽  
A. Martinez-Möller ◽  
M. Schwaiger ◽  
S. I. Ziegler ◽  
S. Fürst ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Image Quality ◽  
Image Noise ◽  
Ct Scanner ◽  
Patient Study ◽  
Surface Coils ◽  
Scan Time ◽  
Pet Ct ◽  
Relative Standard ◽  
Patient Table

SummaryThe surface coils of the Biograph mMR integrated PET/MR system were optimised for PET, but are otherwise unaccounted for. The patient table is still more massive than those of PET/CT devices. The goal was to assess those hardware effects on quantification, count statistics, image quality and scan time both with phantoms and in patients and to investigate their clinical relevance. Patients, material, methods: PET phantom data were acquired with and without the patient table. Image noise was expressed as relative standard deviation and compared to a state-of-the-art PET/CT scanner. Protocols of the phantom/patient study regarding the surface coils were similar. Thoraces/ab- domens of 11 patients were scanned with and without a coil (1 BP, 4 min). Mean uptake and standard deviation in a cubical VOI were derived and expressed as SUV. Results: The patient table reduced the number of true coincidences (trues) by 19% (PET/MR) and by 11% (PET/CT). The scan duration for the mMR had to be increased by approximately 30% to achieve a noise level comparable to that of the PET/CT. Decreased SUVs with coil observed in the phantom were confirmed by the patient study. By removing the coil, the mean liver SUV increased by (6 ± 2)%. With (+3 ± 14)%, the average change was similar in lesions, but exceeded 20% in almost one fifth of them. The number of trues grew by (6 ± 1)% for the patients and by 7% for the phantom. Conclusion: Due to the additional attenuation caused by MR hardware, PET scan durations would have to be increased compared to current PET/CTs to provide similar image noise levels. The effect of the coils is mostly in the order of statistical fluctuations. In tumour lesions, it is more pronounced and shows a larger variability. Therefore, coils should be included in the attenuation correction to ensure accurate quantification and thus comparability across PET/MR and PET/CT scanners and within patient populations.

scholarly journals The Role of Activity, Scan Duration and Patient's Body Mass Index in the Optimization of 18FDG Imaging Protocols on a TOF-PET/CT Scanner

2020 ◽  
Author(s):  
Roberta Matheoud ◽  
Naema Al-Maymani ◽  
Alessia Oldani ◽  
Gian Mauro Sacchetti ◽  
Marco Brambilla ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Image Quality ◽  
Body Mass ◽  
Activity Concentration ◽  
Background Activity ◽  
Whole Body ◽  
Internal Diameter ◽  
Ct Scanner ◽  
Pet Ct ◽  
Tof Pet

Abstract BackgroundTime-of-flight (TOF) PET technology determines a reduction in the noise and improves the reconstructed image quality in low counts acquisitions, such as in overweight patients, allowing a reduction of administered activity and/or imaging time. However, international guidelines and recommendations on 18F-fluoro-2-deoxyglucose (FDG) activity administration scheme are old or only partially account for TOF technology and advanced reconstruction modalities. The aim of this study was to optimize FDG whole-body studies on a TOF PET/CT scanner by using a multivariate approach to quantify how physical figures of merit related to image quality change with acquisition/reconstruction/patient-dependent parameters in a phantom experiment. MethodsThe NEMA-IQ phantom was used to evaluate contrast recovery coefficient (CRC), background variability (BV) and contrast-to-noise ratio (CNR) as a function of changing emission scan duration (ESD), activity concentration (AC), target internal diameter (ID), target-background activity ratio (TBR), and body mass index (BMI). The phantom was filled with an average concentration of 5.3 kBq/mL of FDG solution and the spheres with TBR of 21.2, 8.8, and 5.0 in 3 different sessions. Images were acquired at varying background activity concentration from 5.1 to 1.3 kBq/mL and images were reconstructed for ESD of 30-151 seconds per bed position with and without Point Spread Function (PSF) correction. The parameters were all considered in a single analysis using multiple linear regression methods. ResultsAs expected, CRC depended only on sphere ID and on PSF application, while BV depended on sphere ID, ESD, AC and BMI of the phantom, in order of decreasing relevance. Noteworthy, ESD and AC resulted as the most significant predictors of CNR variability with a similar relevance, followed by the weight of the patient and TBR of the lesion. ConclusionsAC and ESD proved to be effective tools in modulating CNR. ESD could be increased rather than AC to improve image quality in overweight/obese patients to fulfil ALARA principles.

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