Optimization of reconstruction parameters in [18F]FDG PET brain images aiming scan time reduction

Iterative image reconstruction methods are widely used in PET due to their better image quality when compared to analytical methods. However, inaccurate quantification occurs in low activity concentration regions, which leads to biased quantification of PET images. The diagnosis of some neurodegenerative diseases, such as Alzheimer’s disease, is based on identifying such low-uptake regions. Furthermore, PET imaging in these populations should be as short as possible to limit head movements and improve patient comfort. This work aims to identify optimized reconstruction parameters of [18F]FDG PET brain images aiming to reduce image acquisition time with minimal impact on quantification. For this, [18F]FDG PET images of a Hoffman 3-D brain phantom were acquired. Analytical and iterative reconstruction methods were compared utilizing image quality and quantitative accuracy metrics. OSEM reconstruction algorithm was optimized (4 iterations and 32 subsets). It resulted in remarkably similar images compared to the current clinical settings, with a 50% reduction in scan time (5 min with a post-reconstruction filter of 4 mm). Future clinical studies are needed to confirm the results presented here.

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The effect of reduced scan time on response assessment FDG-PET/CT imaging using Deauville score in patients with lymphoma

European Journal of Hybrid Imaging ◽

10.1186/s41824-021-00096-0 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Charlotte Hornnes ◽

Annika Loft ◽

Liselotte Højgaard ◽

Flemming Littrup Andersen

Keyword(s):

Image Quality ◽

Hodgkin Lymphoma ◽

Fdg Pet ◽

Response Assessment ◽

Acquisition Time ◽

List Mode ◽

Deauville Score ◽

Scan Time ◽

Pet Ct ◽

Fdg Pet Ct

Abstract Purpose [18F]Fluoro-deoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT) is used for response assessment during therapy in Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Clinicians report the scans visually using Deauville criteria. Improved performance in modern PET/CT scanners could allow for a reduction in scan time without compromising diagnostic image quality. Additionally, patient throughput can be increased with increasing cost-effectiveness. We investigated the effects of reducing scan time of response assessment FDG-PET/CT in HL and NHL patients on Deauville score (DS) and image quality. Methods Twenty patients diagnosed with HL/NHL referred to a response assessment FDG-PET/CT were included. PET scans were performed in list-mode with an acquisition time of 120 s per bed position(s/bp). From PET list-mode data images with full acquisition time of 120 s/bp and shorter acquisition times (90, 60, 45, and 30 s/bp) were reconstructed. All images were assessed by two specialists and assigned a DS. We estimated the possible savings when reducing scan time using a simplified model based on assumed values/costs for our hospital. Results There were no significant changes in the visually assessed DS when reducing scan time to 90 s/bp, 60 s/bp, 45 s/bp, and 30 s/bp. Image quality of 90 s/bp images were rated equal to 120 s/bp images. Coefficient of variance values for 120 s/bp and 90 s/bp images was significantly < 15%. The estimated annual savings to the hospital when reducing scan time was 8000-16,000 €/scanner. Conclusion Acquisition time can be reduced to 90 s/bp in response assessment FDG-PET/CT without compromising Deauville score or image quality. Reducing acquisition time can reduce costs to the clinic.

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The Impact of Acquisition Time on Image Quality in Whole-Body 18F-FDG PET/CT for Cancer Staging

Journal of Nuclear Medicine Technology ◽

10.2967/jnmt.112.103291 ◽

2012 ◽

Vol 40 (4) ◽

pp. 255-258 ◽

Cited By ~ 8

Author(s):

D. Hausmann ◽

D. J. Dinter ◽

M. Sadick ◽

J. Brade ◽

S. O. Schoenberg ◽

...

Keyword(s):

Image Quality ◽

Fdg Pet ◽

Cancer Staging ◽

Whole Body ◽

Acquisition Time ◽

Pet Ct ◽

18F Fdg ◽

Fdg Pet Ct ◽

The Impact

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Central Nervous System Myelomatosis Delineated by High-Resolution Brain Images From Fully Digital 18F-FDG PET

Clinical Nuclear Medicine ◽

10.1097/rlu.0000000000002243 ◽

2018 ◽

Vol 43 (10) ◽

pp. e372-e373 ◽

Cited By ~ 2

Author(s):

Achraf Bahloul ◽

Mathieu Perrin ◽

Samir Amlal ◽

Pierre-Yves Marie ◽

Antoine Verger

Keyword(s):

Central Nervous System ◽

Nervous System ◽

High Resolution ◽

Fdg Pet ◽

Brain Images ◽

18F Fdg

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Randomized Controlled Trial Examining Effects of Web-Based Information on Patient Satisfaction and Image Quality in 18F-FDG PET/CT Examinations

Journal of Nuclear Medicine Technology ◽

10.2967/jnmt.118.213116 ◽

2018 ◽

Vol 47 (1) ◽

pp. 39-46

Author(s):

Camilla Andersson ◽

Carlos Trampal Pulido ◽

Håkan Ahlström ◽

Birgitta Johansson

Keyword(s):

Randomized Controlled Trial ◽

Patient Satisfaction ◽

Image Quality ◽

Fdg Pet ◽

Controlled Trial ◽

Web Based ◽

Randomized Controlled ◽

Pet Ct ◽

18F Fdg ◽

Fdg Pet Ct

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The Effect of Electroencephalography Leads on Image Quality in Cerebral Perfusion SPECT and 18F-FDG PET/CT

Journal of Nuclear Medicine Technology ◽

10.2967/jnmt.117.207621 ◽

2018 ◽

Vol 46 (4) ◽

pp. 359-361

Author(s):

Lulu Zhang ◽

Stephanie P. Yen ◽

Marc A. Seltzer ◽

George P. Thomas ◽

Kristen Willis ◽

...

Keyword(s):

Image Quality ◽

Fdg Pet ◽

Cerebral Perfusion ◽

Pet Ct ◽

Perfusion Spect ◽

18F Fdg ◽

Fdg Pet Ct

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Can a penalized-likelihood estimation algorithm be used to reduce the injected dose or the acquisition time in 68Ga-DOTATATE PET/CT studies?

10.21203/rs.3.rs-34588/v2 ◽

2020 ◽

Author(s):

Alexandre Chicheportiche ◽

Elinor Goshen ◽

Jeremy Godefroy ◽

Simona Grozinsky-Glasberg ◽

Kira Oleinikov ◽

...

Keyword(s):

Image Reconstruction ◽

Image Quality ◽

Regularization Parameter ◽

Penalized Likelihood ◽

Likelihood Estimation ◽

Whole Body ◽

Acquisition Time ◽

Clinical Images ◽

Penalized Likelihood Estimation ◽

Reconstruction Methods

Abstract Background: Image quality and quantitative accuracy of Positron Emission Tomography (PET) depend on several factors such as uptake time, scanner characteristics and image reconstruction methods. Ordered subset expectation maximization (OSEM) is considered the gold standard for image reconstruction. Penalized-likelihood estimation (PL) algorithms have been recently developed for PET reconstruction to improve quantitation accuracy while maintaining or even improving image quality. In PL algorithms a regularization parameter β controls the penalization of relative differences between neighboring pixels and determines image characteristics. In the present study, we aim to compare the performance of Q.Clear (PL algorithm, GE Healthcare) and OSEM (3 iterations, 8 subsets, 6 mm post-processing filter) for 68Ga-DOTATATE (68Ga-DOTA) PET studies, both visually and quantitatively.Thirty consecutive whole-body 68Ga-DOTA studies were included. The data were acquired in list mode and were reconstructed using 3D OSEM and Q.Clear with various values of β, and various acquisition times per bed position (bp), thus generating images with reduced injected dose (1.5 min/bp: β=300-1100; 1.0 min/bp: β=600-1400 and 0.5 min/bp: β=800-2200). An additional analysis adding β values up to 1500, 1700 and 300 for 1.5, 1.0 and 0.5 min/bp, respectively, was performed for a random sample of 8 studies. Evaluation was performed using a phantom and clinical data. Two experienced nuclear medicine physicians blinded to the variables assessed the image quality visually.Results: Clinical images reconstructed with Q.Clear, set at 1.5, 1.0 min/bp and 0.5 min/bp using β = 1100, 1300, 3000 respectively, resulted in images with noise equivalence to 3D OSEM (1.5 min/bp) with a mean increase in SUVmax of 14%, 13% and 4%, an increase in SNR of 30%, 24% and 10%, and in SBR of 13%, 13% and 2%, respectively. Visual assessment yielded similar results for β values of 1300-1500 and 1500-1700 for 1.5 and 1.0 min/bp, respectively although for 0.5 min/bp there was no significant improvement compared to OSEM. Conclusion: 68Ga-DOTA reconstructions with Q.Clear, 1.5 and 1.0 min/bp resulted in increased tumor SUVmax and in improved SNR and SBR at a similar level of noise compared to 3D OSEM. Q.Clear with β =1500-1700 enables one-third reduction of acquisition time or injected dose, with similar image quality compared to 3D OSEM.

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The image quality, lesion detectability, and acquisition time of 18F-FDG total-body PET/CT in oncological patients

European Journal of Nuclear Medicine and Molecular Imaging ◽

10.1007/s00259-020-04823-w ◽

2020 ◽

Vol 47 (11) ◽

pp. 2507-2515 ◽

Cited By ~ 2

Author(s):

Yi-Qiu Zhang ◽

Peng-Cheng Hu ◽

Run-Ze Wu ◽

Yu-Shen Gu ◽

Shu-Guang Chen ◽

...

Keyword(s):

Image Quality ◽

Acquisition Time ◽

Lesion Detectability ◽

Oncological Patients ◽

Pet Ct ◽

18F Fdg ◽

Total Body

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Capabilities of multi-pinhole SPECT with two stationary detectors for in vivo rat imaging

Scientific Reports ◽

10.1038/s41598-020-75696-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jan P. Janssen ◽

Jan V. Hoffmann ◽

Takayuki Kanno ◽

Naoko Nose ◽

Jan-Peter Grunz ◽

...

Keyword(s):

Image Quality ◽

Point Source ◽

Single Photon ◽

Photon Emission ◽

Small Animal ◽

Acquisition Time ◽

Emission Computed Tomography ◽

Scan Time ◽

Spect System

Abstract We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available 99mTc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with 99mTc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with ~ 100 MBq [99mTc]Tc-MIBI or ~ 150 MBq [99mTc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1 = “very poor” to 5 = “very good”. Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.

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