The association of tumor-to-background ratios and SUVmax deviations related to point spread function and time-of-flight F18-FDG-PET/CT reconstruction in colorectal liver metastases

Rogasch, J; Steffen, Ingo G.; Hofheinz, Frank; Großer, Oliver S.; Furth, Christian; Mohnike, Konrad; Hass, Peter; Walke, Mathias; Apostolova, Ivayla; Amthauer, Holger

doi:10.1186/s13550-015-0111-5

Cited by 37 publications

(27 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other major software technologies have been released, such as time of flight, which improves PET imaging in overweight patients [31], and more recently Bayesian penalised likelihood reconstruction, which allows an increased number of iterations without the increased noise usually seen in conventional OSEM reconstructions [32]. These technologies can be combined with PSF modelling and could further improve the diagnostic performance of PET for the detection of PRD at the cervical level.…”

Section: Discussionmentioning

confidence: 99%

Incremental Value of a Dedicated Head and Neck Acquisition during 18F-FDG PET/CT in Patients with Differentiated Thyroid Cancer

et al. 2016

View full text Add to dashboard Cite

Objectives18F-FDG-PET/CT is a useful tool used to evidence persistent/recurrent disease (PRD) in patients with differentiated thyroid cancer and iodine-refractory lesions. The aim of this study was to compare the diagnostic value at the cervical level of the routine whole-body (WB) acquisition and that of a complementary head and neck (HN) acquisition, performed successively during the same PET/CT study.MethodsPET/CT studies combining WB and HN acquisitions performed in 85 consecutive patients were retrospectively reviewed by two nuclear medicine physicians. 18F-FDG uptake in cervical lymph nodes (LN) or in the thyroid bed was assessed. Among the 85 patients, the PET/CT results of the 26 who subsequently underwent neck surgery were compared with surgical and pathological reports. The size of each largest nodal metastasis was assessed by a pathologist.ResultsIn the 85 patients, inter-observer agreement was excellent for both WB and HN PET/CT interpretation. Of the 26 patients who underwent surgery, 25 had pathology proven PRD in the neck. Of these 25 patients, 15 displayed FDG uptake on either WB or HN PET. In these 15 patients, HN PET detected more malignant lesions than WB PET did (21/27 = 78% vs. 12/27 = 44%, P = 0.006). Node/background ratios were significantly higher on HN than on WB PET (P<0.0001). Three false-negative studies (20%) on WB PET were upstaged as true-positive on HN PET. The mean size of the largest LN metastasis was 3 mm for the LN detected neither on WB nor on HN PET, 7 mm for the metastasis detected on HN but not on WB PET, and 13 mm for those detected on both acquisitions (P = 0.0004). Receiver-Operating Characteristic analysis showed that area under the curve was higher for HN PET than for WB PET (0.97 [95%CI, 0.90–0.99] vs 0.88 [95%CI, 0.78–0.95], P = 0.009).ConclusionsHN acquisition improves the ability to detect PRD in the neck compared with WB acquisition alone. We recommend systematically adding an HN acquisition when PET/CT is performed to detect PRD in the neck.

show abstract

Section: Discussionmentioning

confidence: 99%

Incremental Value of a Dedicated Head and Neck Acquisition during 18F-FDG PET/CT in Patients with Differentiated Thyroid Cancer

et al. 2016

View full text Add to dashboard Cite

show abstract

“…To get a standardized overview of differences between a regular OSEM reconstruction and a BPL reconstruction with β = 450, phantom experiments were performed over a broad range of spherical lesion sizes from 4-40 mm. Spheres were filled with 18 F-FDG at a 10-to-1 ratio of sphere-to-background, mimicking high intensity 18 F-FDG uptake in clinical studies [26]. The axial slice taken at the maximum diameter of the spheres using OSEM+PSF (Fig.…”

Section: Improved Contrast Recovery With Bpl In Phantom Studiesmentioning

confidence: 99%

Evaluation of a Bayesian penalized likelihood reconstruction algorithm for low-count clinical 18F-FDG PET/CT

et al. 2019

View full text Add to dashboard Cite

Background: Recently, a Bayesian penalized likelihood (BPL) reconstruction algorithm was introduced for a commercial PET/CT with the potential to improve image quality. We compared the performance of this BPL algorithm with conventional reconstruction algorithms under realistic clinical conditions such as daily practiced at many European sites, i.e. low 18 F-FDG dose and short acquisition times. Results: To study the performance of the BPL algorithm, regular clinical 18 F-FDG whole body PET scans were made. In addition, two types of phantoms were scanned with 4-37 mm sized spheres filled with 18 F-FDG at sphere-to-background ratios of 10-to-1, 4-to-1, and 2-to-1. Images were reconstructed using standard ordered-subset expectation maximization (OSEM), OSEM with point spread function (PSF), and the BPL algorithm using β-values of 450, 550 and 700. To quantify the image quality, the lesion detectability, activity recovery, and the coefficient of variation (COV) within a single bed position (BP) were determined. We found that when applying the BPL algorithm both smaller lesions in clinical studies as well as spheres in phantom studies can be detected more easily due to a higher SUV recovery, especially for higher contrast ratios. Under standard clinical scanning conditions, i.e. low number of counts, the COV is higher for the BPL (β=450) than the OSEM+PSF algorithm. Increase of the β-value to 550 or 700 results in a COV comparable to OSEM+PSF, however, at the cost of contrast, though still better than OSEM+PSF. At the edges of the axial field of view (FOV) where BPs overlap, COV can increase to levels at which bands become visible in clinical images, related to the lower local axial sensitivity of the PET/CT, which is due to the limited bed overlap of 23% such as advised by the manufacturer. Conclusions:The BPL algorithm performs better than the standard OSEM+PSF algorithm on small lesion detectability, SUV recovery, and noise suppression. Increase of the percentage of bed overlap, time per BP, administered activity, or the β-value, all have a direct positive impact on image quality, though the latter with some loss of small lesion detectability. Thus, BPL algorithms are very interesting for improving image quality, especially in small lesion detectability.

show abstract

“…While the improved CR at a β = 150 can result in higher SUVmax in small pulmonary nodules by 25% [9], such significant intermethod SUV differences may not be observed at β values > 150 [10] and may only be achieved at the cost of high image noise [8]. Furthermore, the performance of TOF and PSF is dependent on the signal-to-background ratio (SBR) and lesion/sphere size [11,12]. Previous studies that compared Q.Clear and conventional methods by only evaluating isolated reconstruction settings may therefore be of limited representativeness.…”

Section: Introductionmentioning

confidence: 99%

Reconstructed spatial resolution and contrast recovery with Bayesian penalized likelihood reconstruction (Q.Clear) for FDG-PET compared to time-of-flight (TOF) with point spread function (PSF)

et al. 2020

Self Cite

View full text Add to dashboard Cite

Background: Bayesian penalized likelihood reconstruction for PET (e.g., GE Q.Clear) aims at improving convergence of lesion activity while ensuring sufficient signal-tonoise ratio (SNR). This study evaluated reconstructed spatial resolution, maximum/ peak contrast recovery (CRmax/CRpeak) and SNR of Q.Clear compared to time-offlight (TOF) OSEM with and without point spread function (PSF) modeling. Methods: The NEMA IEC Body phantom was scanned five times (3 min scan duration, 30 min between scans, background, 1.5-3.9 kBq/ml F18) with a GE Discovery MI PET/CT (3-ring detector) with spheres filled with 8-, 4-, or 2-fold the background activity concentration (SBR 8:1, 4:1, 2:1). Reconstruction included Q.Clear (beta, 150/300/450), "PSF+TOF 4/16 " (iterations, 4; subsets, 16; in-plane filter, 2.0 mm), "OSEM+TOF 4/16 " (identical parameters), "PSF+TOF 2/17 " (2 it, 17 ss, 2.0 mm filter), "OSEM+TOF 2/17 " (identical), "PSF+TOF 4/8 " (4 it, 8 ss, 6.4 mm), and "OSEM+TOF 2/8 " (2 it, 8 ss, 6.4 mm). Spatial resolution was derived from 3D sphere activity profiles. RC as (sphere activity concentration [AC]/true AC). SNR as (background mean AC/ background AC standard deviation). Results: Spatial resolution of Q.Clear 150 was significantly better than all conventional algorithms at SBR 8:1 and 4:1 (Wilcoxon, each p < 0.05). At SBR 4:1 and 2:1, the spatial resolution of Q.Clear 300/450 was similar or inferior to PSF+TOF 4/16 and OSEM+TOF 4/16. Small sphere CRpeak generally underestimated true AC, and it was similar for Q.Clear 150/300/450 as with PSF+TOF 4/16 or PSF+TOF 2/17 (i.e., relative differences < 10%). Q.Clear provided similar or higher CRpeak as OSEM+TOF 4/16 and OSEM+TOF 2/17 resulting in a consistently better tradeoff between CRpeak and SNR with Q.Clear. Compared to PSF+TOF 4/8 /OSEM+TOF 2/8 , Q.Clear 150/300/450 showed lower SNR but higher CRpeak.

show abstract

The association of tumor-to-background ratios and SUVmax deviations related to point spread function and time-of-flight F18-FDG-PET/CT reconstruction in colorectal liver metastases

Cited by 37 publications

References 23 publications

Incremental Value of a Dedicated Head and Neck Acquisition during 18F-FDG PET/CT in Patients with Differentiated Thyroid Cancer

Incremental Value of a Dedicated Head and Neck Acquisition during 18F-FDG PET/CT in Patients with Differentiated Thyroid Cancer

Evaluation of a Bayesian penalized likelihood reconstruction algorithm for low-count clinical 18F-FDG PET/CT

Reconstructed spatial resolution and contrast recovery with Bayesian penalized likelihood reconstruction (Q.Clear) for FDG-PET compared to time-of-flight (TOF) with point spread function (PSF)

Contact Info

Product

Resources

About