Can a Deep Progressive Learning Method Help to Achieve High Image Quality as Total-body PET Imaging?

2021 ◽  
Author(s):  
Taisong Wang ◽  
Wenli Qiao ◽  
Ying Wang ◽  
Jingyi Wang ◽  
Yang Lv ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Image Quality ◽  
Prospective Study ◽  
Real World ◽  
Low Dose ◽  
Acquisition Time ◽  
Learning Method ◽  
List Mode ◽  
Total Body ◽  
Progressive Learning

Abstract Purpose To propose and validate a total-body PET (TB-PET) guided deep progressive learning method (DPR) for low-dose clinical imaging of standard axial field-of-view PET/CT scanner (SAFOV-PET).Methods List-mode raw data from a total of 182 scans were collected, including 100 patient scans from a TB-PET, and 15 phantom and 67 patient scans from a SAFOV-PET. Neural networks employed in DPR were trained with the high-quality images obtained from the TB-PET using a progressive learning strategy and evaluated on a SAFOV-PET through three stages of studies. The CTN phantom was firstly used to verify the effectiveness of protocols in DPR and OSEM algorithms. Subsequently, list-mode rawdata from retrospective and prospective PET oncological patients (n=26 and 41, respectively) were rebinned into short duration scans (referred as to DPR_full, DPR_1/2, DPR_1/3, and DPR_1/4), and reconstructed with DPR. Full-duration data were reconstructed with OSEM to generate images as a reference. In the retrospective study, the image quality was evaluated using the metrics of standard uptake value (SUV) and target-to-liver ratio (TLR) in lesions, and coefficient of variation (COV) in the liver, which provided evidence for the subsequent study with real-world low-dose injection. In the prospective study, the quantification accuracy was evaluated with the agreement of SUVs in the liver, the blood pool, and the muscle between the DPR and the OSEM images. Quantitative analysis was also performed with the SUV and the TLR in lesions, furthermore on small lesions with a diameter no more than 10mm. In addition, qualitative analysis was performed using a 5-point Likert scale on the following perspectives: contrast, noise, and diagnostic confidence. Results The protocols used in the study were verified to meet the EANM EARL2 requirements. In the retrospective study, the DPR group with one-third acquisition time can yield a comparable image quality to the reference. In the prospective study, good agreement of the SUVs between DPR and OSEM was found in all the selected background tissues even if the injected dose was reduced to 1/3. Both quantitative and qualitative results demonstrated that the DPR_1/3 group showed no significant difference with the reference regarding the liver COV and subjective scores. The lesion SUVs and TLRs in the DPR_1/3 group were significantly enhanced compared with the reference, even for small lesions. Conclusions The proposed DPR method can reduce the injected dose of SAFOV-PET scan by up to 2/3 in a real-world deployment while maintaining image quality.

scholarly journals Feasibility of Low-Dose 68Ga-DOTATATE With Short Acquisition Time Using Total-Body PET/CT in Patients With Neuroendocrine Tumor

2021 ◽  
Author(s):  
Jie Xiao ◽  
Haojun Yu ◽  
Hongyan Yin ◽  
Guobin Liu ◽  
Yan Hu ◽  
...  
Keyword(s):  
Image Quality ◽  
Dose Regimen ◽  
Low Dose ◽  
Signal To Noise Ratio ◽  
Subjective Evaluation ◽  
Blood Pool ◽  
Acquisition Time ◽  
Short Acquisition Time ◽  
Pet Ct ◽  
Total Body

Abstract Purpose To explore the feasibility of a low dose regimen with short acquisition time of 68Ga-DOTATATE total-body PET/CT without compromising image quality of patients with NETs. Methods Fifty-seven consecutive NETs patients who underwent 68Ga-DOTATATE total-body PET/CT, with a low dose regimen (0.8-1.2 MBq/kg) of 68Ga-DOTATATE and acquisition time of 10 min prior to any treatment, were enrolled in the present study. The PET data were split into 1 min, 2 min, 3 min, 4 min, 5 min, 8 min and 10 min reconstruction groups, referenced as R1, R2, R3, R4, R5, R8 and R10. The subjective evaluation of image quality was scored in 5-point Likert scale based on three aspects: the overall impression of the image quality, the image noise, the lesion detectability. The objective image quality was assessed by the signal-to-noise ratio of liver (SNRL), the coefficient of variation (CV), the SUVmax, SUVmean, SD of liver, mediastinal blood pool and lesion, the tumor-liver ratio (TLR), the tumor-mediastinal blood pool-ratio (TMR) of lesion. Results The sufficient subjective image quality with a score of 3.44±0.53 could be obtained at 3 min acquisition duration, with a kappa value of 0.90. In quantitative analysis, the value of SNRL is over 10 in all reconstruction groups. As the acquisition time increases, SNRL was increased and CV was decreased within 3 min, while SNRL and CV showed no significant different between R4-R10. There was no significant different in TMR and TLR of lesion between R1-R10 (all p < 0.05). Referenced as PET images of R10, 90 SSTR-positive lesions are identified, and all those lesions are found in the R1-R10 groups (100%).Conclusion The low-dose (0.8-1.2 MBq/kg) 68Ga-DOTATATE total-body PET/CT not only shortens acquisition time, but maintains a sufficient image quality for the NETs patients.

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

2020 ◽  
Vol 47 (11) ◽  
pp. 2507-2515 ◽  
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

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 Impact of Varying Number of OSEM Iterations on Standardized Uptake Value and Image Quality of Discovery STE PET/CT Scanner

2018 ◽  
Vol 4 (Supplement 2) ◽  
pp. 68s-68s
Author(s):  
B. Ali ◽  
A. Afshan ◽  
M.B. Kakakhel
Keyword(s):  
Image Quality ◽  
Standardized Uptake Value ◽  
Acquisition Time ◽  
List Mode ◽  
Ct Scanner ◽  
Matrix Size ◽  
Cold Lesion ◽  
Pet Ct ◽  
The Impact

Background: In PET imaging both quantitative and qualitative interpretations are used. Qualitative and quantitative interpretations depend upon PET/CT image quality that along with many biologic factors strongly depends upon image reconstruction parameters. Aim: The objective of this experimental work was to study the impact of one of the key reconstruction parameter, i.e., number of reconstruction iteration, on standardized uptake value and image quality of PET/CT scan. Methods: Images of NEMA IEC Image Quality Phantom were acquired in list mode for 10 mins on Discovery STE PET/CT scanner, using tumor to background ratio of 4:1 and 18F-FDG as radiotracer. List mode data were further transformed into data sets of varying acquisition time (0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 mins) per bed position. Transformed data set of 5.0 mins were used to study the impact of varying number of iterations (2, 3, 4, 5, 7, 10, 15, 20) using OSEM approach of iterative reconstruction. Standardized uptake value (SUV) and underestimation in SUV were calculated as quantitative measures, while hot lesion contrast, cold lesion contrast and background variability were calculated as qualitative measures. Results: Standardized uptake value, hot and cold lesion contrast, image spatial resolution and background variability showed increasing trend with increase in reconstruction iterations. Maximum increase of 20.25%, 16.33%, 9.79% and 6.88% was observed in SUV for 10 mm, 13 mm, 17 mm and 22 mm lesions as number of iteration change from 2 to 3. Smallest and the largest diameter lesions showed maximum underestimations of 54.67% and 8.20% at 2 iterations respectively. Percentage hot lesion contrast showed rapid increase as the number of iteration change from 2 to 7 and increased slowly afterward. Background variability range from 4.4% to 6.4%, 4.1%–5.7%, 3.6%–4.6%, 3%–3.8%, 2.7%–3.2%, 2.4%–2.7% for 10.0 mm, 13.0 mm, 17.0 mm, 22.0 mm, 28.0 mm and 37.0 mm sphere respectively. Conclusion: Optimized reconstruction parameters for routine clinical studies 3 iterations with image matrix size of 128 × 128 with filters FWHM of 6 mm and for high resolution studies 3 iterations image matrix size of 256×256 with filters FWHM of 6 mm.

scholarly journals Diagnostic Performance and Image Quality of 20-second Breath-hold Total-body PET/CT Acquisition in Stage Ia Pulmonary Adenocarcinoma

2021 ◽  
Author(s):  
Yanhua Duan ◽  
Minjie Zhao ◽  
Keyu Zan ◽  
Ying Wang ◽  
Xiao Cui ◽  
...  
Keyword(s):  
Image Quality ◽  
Subgroup Analysis ◽  
Diagnostic Performance ◽  
Pulmonary Adenocarcinoma ◽  
Acquisition Time ◽  
Breath Hold ◽  
Pet Ct ◽  
Stage Ia ◽  
Total Body

Abstract PurposeThe study is to evaluate the diagnostic performance and image quality of a 20-second breath-hold (BH) 18F-FDG total-body PET acquisition compared with a free-breathing (FB) PET for stage IA pulmonary adenocarcinoma.Materials and MethodsForty-seven patients with confirmed stage IA pulmonary adenocarcinoma were enrolled. All patients underwent total-body 18F–FDG PET/CT and the acquisition time was 300 s, followed by a 20-s BH PET. A 20-s FB PET was extracted from the 300-s PET. The size and volume of lesions were measured on BHCT images. The SUVmax, tumor-to-background ratio (TBR), metabolic tumor volume (MTV), %ΔSUVmax and %ΔTBR of the lesions were measured and recorded. The lesions were further divided by distance from pleura, lesion size, and morphological characteristic for subgroup analysis. ResultsIn the cohort and subgroup analysis, the SUVmax and TBR were significantly increased with 20-BH PET compared with 300-FB PET and 20-FB PET (all p＜0.05). And the %ΔSUVmax and %ΔTBR in D1 groups (≤10 mm in distance) higher than those in D2 and D3 groups (＞10 mm). The diagnostic performance of BH PET was significantly higher than that of FB PET (all p＜0.001). The Bland-Altman plot for agreement on lesion’s volume between BH PET and CT showed good agreement than FB PET.ConclusionThe 20-s BH PET acquisition is more sensitive to quantitative and qualitative analysis for stage IA pulmonary adenocarcinoma. 20-s BH PET/CT acquisition reduces the blurring effect of respiratory motion especially for subpleural nodules (≤10 mm in distance).

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

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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