scholarly journals Can the BMI-Based Dose Regimen be Used to Reduce Injection Activity and to Obtain a Constant Image Quality in Oncological Patients by 18F-FDG Total-Body PET/CT Imaging?

2021 ◽  
Author(s):  
Jie Xiao ◽  
Haojun Yu ◽  
Xiuli Sui ◽  
Yan Hu ◽  
Cao Yanyan ◽  
...  
Keyword(s):  
Image Quality ◽  
Dose Regimen ◽  
Qualitative Assessment ◽  
Acquisition Time ◽  
Quadratic Relation ◽  
Patient Cohort ◽  
Oncological Patients ◽  
Pet Ct ◽  
Patient Size ◽  
Total Body

Abstract Purpose PET image quality is influenced by the patient size according to the current guideline. The purpose was to propose an optimized dose regimen to yield a constant image quality independent of patient size to meet the clinical needs.Methods A first patient cohort of 78 consecutives for oncological patients (59.7±13.7 years) who underwent a total-body PET/CT scan were retrospectively enrolled to develop the regimen. The patients were equally distributed in four BMI groups according to WHO criteria. The liver SNR (Signal noise ratio, SNRL) was obtained through manually drawing ROIs and normalized (SNRnorm) by the injected activity and acquisition time. And fits of SNRnorm against different patient-dependent parameters were performed to determine the best correlating parameter and fit method. A qualitative assessment on image quality was performed using a 5-point Likert scale to determine the acceptable threshold of SNRL. And thus, an optimized regimen was proposed and validated by a second patient cohort with prospectively enrolled 38 oncological patients. Results The linear fit showed SNRnorm was the strongest correlation (R2 = 0.69) with the BMI than other patient-dependent parameters. The qualitative assessment revealed a SNRL of 14.0 as a threshold to achieve a sufficient image quality. The optimized dose regimen was determined as a quadratic relation with BMI: Injected activity = 39.2 MBq/(-0.03*BMI+1.49)2. In the validation study, the SNRL no longer decreased with the increase of BMI. There was no significant difference of the image quality, the SNRL, between different BMI groups (p > 0.05). In addition, the injected activity was reduced by 75.6±2.9 %, 72.1±4.0 %, 67.1±4.4 % and 64.8±3.5 % compared to the first cohort for the four BMI groups, respectively.Conclusion The study recommended a quadratic relation between the 18F-FDG injected activity and the patient’s BMI and propose a regimen for total-body PET imaging. In the regimen, the image quality can maintain in a constant level independent of patient size and meet the clinical requirement even with a reduced injected activity.

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 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.

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 Total-body 18F-FDG PET Scan in Oncological Patients: How Fast could it be?

2021 ◽  
Author(s):  
Pengcheng Hu ◽  
Yiqiu Zhang ◽  
Haojun Yu ◽  
Shuguang Chen ◽  
Hui Tan ◽  
...  
Keyword(s):  
Image Quality ◽  
Phantom Study ◽  
Pet Scan ◽  
Clinical Settings ◽  
Recovery Coefficient ◽  
Clinical Images ◽  
Oncological Patients ◽  
Pet Ct ◽  
Significant Difference ◽  
Total Body

Abstract Purpose: The aim of the study was to explore a fast PET scan protocol of the total-body uEXPLORER scanner by assessing the image quality consistent to that of a conventional digital PET/CT scanner both from the phantom and clinical perspectives.Methods: The phantom study using a NEMA/IEC NU-2 body phantom was performed both on a total-body PET/CT (uEXPLORER) and a digital routine PET/CT (uMI 780), with hot sphere to background activity concentration ratio of 4:1. The contrast recovery coefficient (CRC), background variability (BV), recovery coefficient RCmax and RCmean were assessed and compared between that in uEXPLORER with the different scanning duration and reconstruction protocols and that in uMI 780 with clinical settings. The coefficient of variation (COV) of the uMI 780 with clinical settings were calculated and used as a threshold to determine the optimized scanning duration and reconstruction protocols were, which can provide a consistent image quality for the two scanners. And subsequently, the proposed protocol was validated by 30 oncological patients. Images acquired in uMI 780 with a 2-3 minute for each bed position were referred as G780. All PET raw data were reconstructed using data-cutting technique to simulate a 30s, 45s or 60s acquisition duration on uEXPLORER. The iterations were 2 and 3 for uEXPLORER, referred as G30s_3i, G45s_2i, G45s_3i, G60s_2i, and G60s_3i. A 5-point Likert scale was used in the qualitative analysis to assess the image quality. The image quality was also compared with the liver COV, the lesion target-to-background ratio (TBR), and the lesion signal-to-noise ratio (SNR).Results: In the phantom study, CRC, BV, RCmax and RCmean in uEXPLORER with different scanning duration and reconstruction iterations were compared with that in uMI 780 with clinical settings and a minor fluctuation was found among different scanning durations. COV of the uMI 780 with clinical settings was 11.6% and determined protocol with a 30-45s scanning duration and 2 or 3 iterations to provide a similar image quality.In the quantitative analysis on the clinical images, there was no significant difference between G780 and G45s_3i. All the other groups in uEXPLORER with a 45s- and above acquisition showed a significantly improved image quality than that in uMI 780 with clinical settings. Comparing the liver COV, there was no significantly difference between G780 and G30s_3i. And no significant difference in lesion TBR was identified between G780 and G45s_2i, while uEXPLORER had a better performance in lesion SNR compared to that in uMI 780 with clinical settings. Conclusions: This study demonstrated a fast PET protocol with a 30-45s acquisition in uEXPLORER with consistent image quality to that in uMI 780 with clinical settings.

Acquisition Protocols to Optimize 68Ga-DOTA-NOC Position Emission Tomography/Computer Tomography Image Quality Based on Patient Body Mass Index and Injected Dose

2020 ◽  
Vol 10 (2) ◽  
pp. 508-514
Author(s):  
Lei Xu ◽  
Lei Lei Zhou ◽  
Zhenyu Zhao ◽  
Qingle Meng ◽  
Rui Yang ◽  
...  
Keyword(s):  
Image Quality ◽  
Dose Group ◽  
Group Versus ◽  
Normal Weight ◽  
Emission Tomography ◽  
Acquisition Time ◽  
Position Emission Tomography ◽  
Weight Group ◽  
Pet Ct ◽  
Overweight Group

Background: The choice of 68Ga-DOTA-1-Nal3-octreotide (68Ga-DOTA-NOC) injected dose and Position emission tomography/computer tomography (PET/CT) acquisition time is still a challenge for obtaining consistently high-quality PET image. Objective: To determine the optimal acquisition protocols based on patient body mass index (BMI) and the injected dose per kilogram for 68Ga-DOTA-NOC PET/CT imaging. Patients and Methods: This was a retrospective analysis of 51 patients (21 males and 30 females) who underwent clinical 68Ga-DOTANOC PET/CT imaging from November 2016 to March 2018 in Nanjing first hospital, the average BMI of these patients was 23.18 ± 3.45 kg/m2 with injected dose of 39.55–110.11 MBq. The study population was classified into groups based on Chinese standard BMI and injected dose. PET image quality and acquisition time were evaluated by coefficient of variance (CV) in the liver slice. Results: (1) The CV significantly increased with increasing weight and BMI (r = 0.647, 0.483, all P < 0.01), and significantly decreased with increasing injected dose per kilogram (r = 0 695, P < 0.01). (2) The CV differed significantly among 4 BMI-based groups, except for normal-weight group versus overweight group and overweight group versus obese group (P < 0.01), and the ratio of overweight group and obese group to normal weight group was approximately 1.1 and 1.2, respectively. Meanwhile, the CV had a significant statistical difference among 3 injected dose per kilogram groups (P < 0.01), and the ratio of that for low dose group and high dose group to moderate dose group was approximately 1.2 and 0.8. Conclusion: The findings showed a feasibility of obtaining consistently high-quality PET image at low injected dose and shorter acquisition time. Estimation of optimal acquisition time and injected dose using CV is valid in improving PET image quality, which can provide reference for the establishment and promotion of 68Ga-DOTA-NOC imaging protocols in China.

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.

PET/CT BiographTM Sensation 16

2006 ◽  
Vol 45 (03) ◽  
pp. 126-133 ◽  
Author(s):  
Y. Bercier ◽  
M. Schwaiger ◽  
S. I. Ziegler ◽  
M.-J. Martínez
Keyword(s):  
Image Quality ◽  
Count Rate ◽  
Signal To Noise Ratio ◽  
Reconstruction Algorithm ◽  
Considerable Change ◽  
Acquisition Time ◽  
Average Increase ◽  
Scatter Fraction ◽  
Pet Ct ◽  
Before And After

SummaryAim: The new PET/CT Biograph Sensation 16 (BS16) tomographs have faster detector electronics which allow a reduced timing coincidence window and an increased lower energy threshold (from 350 to 400 keV). This paper evaluates the performance of the BS16 PET scanner before and after the Pico-3D electronics upgrade. Methods: Four NEMA NU 2–2001 protocols, (i) spatial resolution, (ii) scatter fraction, count losses and random measurement, (iii) sensitivity, and (iv) image quality, have been performed. Results: A considerable change in both PET count-rate performance and image quality is observed after electronics upgrade. The new scatter fraction obtained using Pico-3D electronics showed a 14% decrease compared to that obtained with the previous electronics. At the typical patient background activity (5.3 kBq/ml), the new scatter fraction was approximately 0.42. The noise equivalent count-rate (RNEC) performance was also improved. The value at which the RNEC curve peaked, increased from 3.7·104s-1 at 14 kBq/ml to 6.4·104s-1 at 21 kBq/ml (2R-NEC rate). Likewise, the peak true count-rate value increased from 1.9·105s-1 at 22 kBq/ml to 3.4·105s-1 at 33 kBq/ml. An average increase of 45% in contrast was observed for hot spheres when using AW-OSEM (4ix8s) as the reconstruction algorithm. For cold spheres, the average increase was 12%. Conclusion: The performance of the PET scanners in the BS16 tomographs is improved by the optimization of the signal processing. The narrower energy and timing coincidence windows lead to a considerable increase of signal- to-noise ratio. The existing combination of fast detectors and adapted electronics in the BS16 tomographs allow imaging protocols with reduced acquisition time, providing higher patient throughput.

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