scholarly journals Direct comparison of brain [18F]FDG images acquired by SiPM-based and PMT-based PET/CT: phantom and clinical studies

2020 ◽  
Author(s):  
Kei Wagatsuma ◽  
Muneyuki Sakata ◽  
Kenji Ishibashi ◽  
Akira Hirayama ◽  
Hirofumi Kawakami ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Clinical Studies ◽  
Image Noise ◽  
Image Contrast ◽  
Z Score ◽  
Silicon Photomultiplier ◽  
Timing Resolution ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
Z Scores

Abstract Background: Silicon photomultiplier-positron emission tomography (SiPM-PET) has better sensitivity, spatial resolution, and timing resolution than photomultiplier tube (PMT)-PET. The present study aimed to clarify the advantages of SiPM-PET in 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) brain imaging in a head-to-head comparison with PMT-PET in phantom and clinical studies.Methods: Contrast was calculated from images acquired from a Hoffman 3D brain phantom and image noise and uniformity were calculated from images acquired from a pool phantom using SiPM- and PMT-PET. Sequential PMT-PET and SiPM-PET [18F]FDG images were acquired over a period of 10 min from 22 controls and 10 patients. All images were separately normalized to a standard [18F]FDG PET template, then mean standardized uptake values (SUVmean) and Z-score were calculated using MIMneuro and CortexID Suite, respectively.Results: Image contrast, image noise, and uniformity in SiPM-PET changed 19.2%, 3.5%, and -40.0% from PMT-PET, respectively. These physical indices of both PET scanners satisfied the criteria for acceptable image quality published by the Japanese Society of Nuclear Medicine of contrast > 55%, CV ≤ 15% and SD ≤ 0.0249, respectively. Contrast was 70.0% for SiPM-PET without TOF and 59.5% for PMT-PET without TOF. The TOF improved contrast by 3.5% in SiPM-PET. The SUVmean using SiPM-PET was significantly higher than PMT-PET and did not correlate with a time delay. Z-scores were also significantly higher in images acquired from SiPM-PET (except for the bilateral posterior cingulate) than PMT-PET because the peak signal that was extracted by the calculation of Z-score in CortexID Suite was increased. The hypometabolic area in statistical maps was reduced and localized using SiPM-PET. The trend was independent of whether the images were derived from controls or patients.Conclusions: The improved spatial resolution and sensitivity of SiPM-PET contributed to better image contrast and uniformity in brain [18F]FDG images. The SiPM-PET offers better quality and more accurate quantitation of brain PET images. The SUVmean and Z-scores were higher in SiPM-PET than PMT-PET due to improved PVE. [18F]FDG images acquired using SiPM-PET will help to improve diagnostic outcomes based on statistical image analysis because SiPM-PET would localize the distribution of glucose metabolism on Z-score maps.

scholarly journals Direct comparison of brain [18F]FDG images acquired by SiPM-based and PMT-based PET/CT: phantom and clinical studies

2020 ◽  
Author(s):  
Kei Wagatsuma ◽  
Muneyuki Sakata ◽  
Kenji Ishibashi ◽  
Akira Hirayama ◽  
Hirofumi Kawakami ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Clinical Studies ◽  
Image Noise ◽  
Image Contrast ◽  
Z Score ◽  
Silicon Photomultiplier ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
Z Scores ◽  
18F Fdg

Abstract Background: The silicon photomultiplier-positron emission tomography (SiPM-PET) developed by GE Healthcare has better sensitivity, spatial resolution, and timing resolution than photomultiplier tubes (PMT)-PET. The present study aimed to clarify the advantages of SiPM-PET in 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) brain imaging in a head-to-head comparison with PMT-PET in phantom and clinical studies. Methods: Image contrast was calculated from images acquired from a Hoffman 3D brain phantom and image noise and uniformity were calculated from pooled images acquired from a pool phantom using SiPM- and PMT-PET. Sequential PMT-PET and SiPM-PET [18F]FDG images were acquired over a period of 10 min from 22 controls and 10 patients. All images were separately normalized to a standard [18F]FDG PET template, then mean standardized uptake values (SUVmean) and Z-score were calculated by MIMneuro and CortexID Suite, respectively. Results: Image contrast, image noise, and uniformity in SiPM-PET changed 19.2%, 3.5%, and -40.0% from PMT-PET, respectively. These physical indices of both PET scanners satisfied the criteria for acceptable image quality published by the Japanese Society of Nuclear Medicine of > 55%, ≤ 15% and ≤ 0.0249, respectively. The contrast in SiPM-PET was slightly improved using TOF. The SUVmean using SiPM-PET was significantly higher than PMT-PET and did not correlate with a time delay. Z-scores were also significantly higher in images acquired from SiPM-PET (except for the bilateral posterior cingulate) than PMT-PET because the peak signal that was extracted by the calculation of Z-score in CortexID Suite was raised. The area of hypometabolism in statistical maps was reduced and localized by SiPM-PET compared with PMT-PET regardless of whether the images were derived from controls or patients. Conclusions: The improved spatial resolution and sensitivity of SiPM-PET contributed to better image contrast and uniformity in brain [18F]FDG images. The SiPM-PET offers better quality and more accurate quantitation of brain PET images. The SUVmean and Z-score in SiPM-PET was higher than PMT-PET due to improving the PVEs. [18F]FDG images acquired using SiPM-PET will help to improve diagnostic outcomes based on statistical image analysis becausethe SiPM-PET would localize the distribution of glucose metabolism on Z-score maps.

scholarly journals Direct comparison of brain [18F]FDG images acquired by SiPM-based and PMT-based PET/CT: phantom and clinical studies

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Kei Wagatsuma ◽  
Muneyuki Sakata ◽  
Kenji Ishibashi ◽  
Akira Hirayama ◽  
Hirofumi Kawakami ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Clinical Studies ◽  
Image Noise ◽  
Image Contrast ◽  
Silicon Photomultiplier ◽  
Timing Resolution ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
Pet Ct ◽  
Pet Scanners

Abstract Background Silicon photomultiplier-positron emission tomography (SiPM-PET) has better sensitivity, spatial resolution, and timing resolution than photomultiplier tube (PMT)-PET. The present study aimed to clarify the advantages of SiPM-PET in 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) brain imaging in a head-to-head comparison with PMT-PET in phantom and clinical studies. Methods Contrast was calculated from images acquired from a Hoffman 3D brain phantom, and image noise and uniformity were calculated from images acquired from a pool phantom using SiPM- and PMT-PET. Sequential PMT-PET and SiPM-PET [18F]FDG images were acquired over a period of 10 min from 22 controls and 10 patients. All images were separately normalized to a standard [18F]FDG PET template, then the mean standardized uptake values (SUVmean) and Z-score were calculated using MIMneuro and CortexID Suite, respectively. Results Image contrast, image noise, and uniformity in SiPM-PET changed 19.2, 3.5, and − 40.0% from PMT-PET, respectively. These physical indices of both PET scanners satisfied the criteria for acceptable image quality published by the Japanese Society of Nuclear Medicine of contrast > 55%, CV ≤ 15%, and SD ≤ 0.0249, respectively. Contrast was 70.0% for SiPM-PET without TOF and 59.5% for PMT-PET without TOF. The TOF improved contrast by 3.5% in SiPM-PET. The SUVmean using SiPM-PET was significantly higher than PMT-PET and did not correlate with a time delay. Z-scores were also significantly higher in images acquired from SiPM-PET (except for the bilateral posterior cingulate) than PMT-PET because the peak signal that was extracted by the calculation of Z-score in CortexID Suite was increased. The hypometabolic area in statistical maps was reduced and localized using SiPM-PET. The trend was independent of whether the images were derived from controls or patients. Conclusions The improved spatial resolution and sensitivity of SiPM-PET contributed to better image contrast and uniformity in brain [18F]FDG images. The SiPM-PET offers better quality and more accurate quantitation of brain PET images. The SUVmean and Z-scores were higher in SiPM-PET than PMT-PET due to improved PVE. [18F]FDG images acquired using SiPM-PET will help to improve diagnostic outcomes based on statistical image analysis because SiPM-PET would localize the distribution of glucose metabolism on Z-score maps.

scholarly journals Direct comparison of [18F]FDG brain images acquired from a phantom and patients using SiPM- and PMT-PET/CT

2020 ◽  
Author(s):  
Kei Wagatsuma ◽  
Muneyuki Sakata ◽  
Kenji Ishibashi ◽  
Akira Hirayama ◽  
Hirofumi Kawakami ◽  
...  
Keyword(s):  
Image Noise ◽  
Image Contrast ◽  
Z Score ◽  
Silicon Photomultiplier ◽  
Brain Images ◽  
Background Count ◽  
Timing Resolution ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
Contrast Image

Abstract Background Silicon photomultiplier-positron emission tomography (SiPM-PET) has better sensitivity, spatial resolution, and timing resolution than photomultiplier tubes (PMT)-PET. The present study aimed to clarify the advantages of SiPM-PET in 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) brain imaging in a head-to-head comparison with PMT-PET in phantom and clinical studies. Methods Image contrast was calculated from images acquired from a Hoffman 3D brain phantom and image noise and uniformity were calculated from pooled images acquired from a pool phantom using SiPM- and PMT-PET. Sequential PMT-PET and SiPM-PET [18F]FDG images were acquired over a period of 10 min from 22 individuals. All images were separately normalized to a standard [18F]FDG PET template, then mean standardized uptake values (SUVmean) and Z-score were calculated by MIMneuro and Cortex ID Suite, respectively. Results Image contrast, image noise, and uniformity in SiPM-PET changed 27.5%, -2.1%, and − 138.2% from PMT-PET, respectively. These physical indices of SiPM-PET satisfied the criteria for acceptable image quality published by the Japanese Society of Nuclear Medicine of > 55%, ≤ 15% and ≤ 0.0249, respectively. The residual background count was reduced with time-of-flight algorithm especially in SiPM-PET. The SUVmean using SiPM-PET was significantly higher than PMT-PET and did not correlate with a time delay. Z-scores were also significantly higher in images acquired from SiPM-PET (except for the bilateral posterior cingulate) than PMT-PET because the peak signal that was extracted by the calculation of Z-score in Cortex ID Suite was raised. Conclusions The better spatial and timing resolution, and sensitivity in SiPM-PET were contributed to better image contrast, image noise, and uniformity on brain [18F]FDG images. SiPM-PET offers better quality and more accurate quantitation of brain PET images. The SUVmean and Z-score in SiPM-PET was higher than PMT-PET. [18F]FDG images acquired using SiPM-PET will help to improve diagnostic outcomes based on the statistical image analysis because the SiPM-PET was more localized the distribution of glucose metabolism on Z-score maps.

scholarly journals Comparison between silicon photomultiplier-based and conventional PET/CT in patients with suspected lung cancer—a pilot study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Johan Economou Lundeberg ◽  
Jenny Oddstig ◽  
Ulrika Bitzén ◽  
Elin Trägårdh
Keyword(s):  
Lung Cancer ◽  
Expectation Maximization ◽  
Image Interpretation ◽  
Imaging Study ◽  
Reconstruction Algorithm ◽  
Tnm Staging ◽  
Reconstruction Algorithms ◽  
Silicon Photomultiplier ◽  
Standardized Uptake Values ◽  
Pet Ct

Abstract Background Lung cancer is one of the most common cancers in the world. Early detection and correct staging are fundamental for treatment and prognosis. Positron emission tomography with computed tomography (PET/CT) is recommended clinically. Silicon (Si) photomultiplier (PM)-based PET technology and new reconstruction algorithms are hoped to increase the detection of small lesions and enable earlier detection of pathologies including metastatic spread. The aim of this study was to compare the diagnostic performance of a SiPM-based PET/CT (including a new block-sequential regularization expectation maximization (BSREM) reconstruction algorithm) with a conventional PM-based PET/CT including a conventional ordered subset expectation maximization (OSEM) reconstruction algorithm. The focus was patients admitted for 18F-fluorodeoxyglucose (FDG) PET/CT for initial diagnosis and staging of suspected lung cancer. Patients were scanned on both a SiPM-based PET/CT (Discovery MI; GE Healthcare, Milwaukee, MI, USA) and a PM-based PET/CT (Discovery 690; GE Healthcare, Milwaukee, MI, USA). Standardized uptake values (SUV) and image interpretation were compared between the two systems. Image interpretations were further compared with histopathology when available. Results Seventeen patients referred for suspected lung cancer were included in our single injection, dual imaging study. No statically significant differences in SUVmax of suspected malignant primary tumours were found between the two PET/CT systems. SUVmax in suspected malignant intrathoracic lymph nodes was 10% higher on the SiPM-based system (p = 0.026). Good consistency (14/17 cases) between the PET/CT systems were found when comparing simplified TNM staging. The available histology results did not find any obvious differences between the systems. Conclusion In a clinical setting, the new SiPM-based PET/CT system with a new BSREM reconstruction algorithm provided a higher SUVmax for suspected lymph node metastases compared to the PM-based system. However, no improvement in lung cancer detection was seen.

Dental Caries Severity and Nutritional Status of Nigerian Preschool Children

2021 ◽  
pp. 238008442110021
Author(s):  
O.O. Olatosi ◽  
A.A. Alade ◽  
T. Naicker ◽  
T. Busch ◽  
A. Oyapero ◽  
...  
Keyword(s):  
Early Childhood ◽  
Dental Caries ◽  
Nutritional Status ◽  
Early Childhood Caries ◽  
Z Score ◽  
Cross Sectional ◽  
Risk Of Death ◽  
Malnourished Children ◽  
Z Scores ◽  
Childhood Caries

Introduction: Malnutrition in children is one of the most prevalent global health challenges, and malnourished children have a higher risk of death from childhood diseases. Early childhood caries (ECC) is the most common chronic disease of childhood. Complications from ECC such as pain, loss of tooth/teeth, and infection can undermine a child’s nutrition and growth. Aim: This study aims to evaluate the severity of decay, missing, and filled tooth (dmft) by nutritional status using the z scores of the anthropometric measurements: height for age (HFA), weight for age (WFA), weight for height (WFH), and body mass index for age (BMIA) among children with ECC in Nigeria. Study Design: This is a cross-sectional study conducted in 5 local government areas (LGAs) in Lagos State, Nigeria. A multistage sampling technique was used. Results: A total of 273 cases of ECC were included in the analyses (mean age 4.19 ± 0.96 y). Overall, the mean dmft was 3.04 ± 2.28, and most (96%) were accounted for by untreated decay. The distribution of dmft within the different z score categories of BMIA (<–3 = severely wasted, –2 to –3 = wasted, –2 to +2 = normal, +2 to +3 = overweight and >+3 = obese) showed the highest dmft scores among the combined severely wasted and wasted groups, lowest among children with normal z scores, and intermediate in the overweight and obese groups. There was a significant negative correlation between BMIA z score, WFH z score, and dmft ( r = −0.181, P < 0.05 and r = −0.143, P < 0.05, respectively). However, the correlations between HFA z score, WFA z score, and dmft were positive but not significant ( r = 0.048, P = 0.44 and r = 0.022, P = 0.77, respectively). Conclusion: Our study showed an increased severity of dental caries among severely wasted or wasted children with ECC compared to those of normal or overweight. Knowledge Transfer Statement: The results from this study will raise awareness among clinicians and policy makers on the need for a primary prevention program for early childhood caries in countries with high burden of malnutrition and limited resources. Also, it will help draw the attention of clinicians to the caries status of malnourished children that can be managed to improve the nutritional outcomes.

scholarly journals Phantom and clinical assessment of small pulmonary nodules using Q.Clear reconstruction on a silicon-photomultiplier-based time-of-flight PET/CT system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhifang Wu ◽  
Binwei Guo ◽  
Bin Huang ◽  
Xinzhong Hao ◽  
Ping Wu ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Pulmonary Nodules ◽  
Medium Size ◽  
Ct Reconstruction ◽  
Reconstruction Algorithms ◽  
Silicon Photomultiplier ◽  
Standardized Uptake Values ◽  
Pet Ct ◽  
Quantification Accuracy ◽  
Small Pulmonary Nodules

AbstractTo evaluate the quantification accuracy of different positron emission tomography-computed tomography (PET/CT) reconstruction algorithms, we measured the recovery coefficient (RC) and contrast recovery (CR) in phantom studies. The results played a guiding role in the partial-volume-effect correction (PVC) for following clinical evaluations. The PET images were reconstructed with four different methods: ordered subsets expectation maximization (OSEM), OSEM with time-of-flight (TOF), OSEM with TOF and point spread function (PSF), and Bayesian penalized likelihood (BPL, known as Q.Clear in the PET/CT of GE Healthcare). In clinical studies, SUVmax and SUVmean (the maximum and mean of the standardized uptake values, SUVs) of 75 small pulmonary nodules (sub-centimeter group: < 10 mm and medium-size group: 10–25 mm) were measured from 26 patients. Results show that Q.Clear produced higher RC and CR values, which can improve quantification accuracy compared with other methods (P < 0.05), except for the RC of 37 mm sphere (P > 0.05). The SUVs of sub-centimeter fludeoxyglucose (FDG)-avid pulmonary nodules with Q.Clear illustrated highly significant differences from those reconstructed with other algorithms (P < 0.001). After performing the PVC, highly significant differences (P < 0.001) still existed in the SUVmean measured by Q.Clear comparing with those measured by the other algorithms. Our results suggest that the Q.Clear reconstruction algorithm improved the quantification accuracy towards the true uptake, which potentially promotes the diagnostic confidence and treatment response evaluations with PET/CT imaging, especially for the sub-centimeter pulmonary nodules. For small lesions, PVC is essential.

scholarly journals Deep learning-based image quality improvement of 18F-fluorodeoxyglucose positron emission tomography: a retrospective observational study

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Junichi Tsuchiya ◽  
Kota Yokoyama ◽  
Ken Yamagiwa ◽  
Ryosuke Watanabe ◽  
Koichiro Kimura ◽  
...  
Keyword(s):  
Deep Learning ◽  
Image Quality ◽  
Emission Tomography ◽  
Gaussian Filter ◽  
Fluorodeoxyglucose Positron Emission Tomography ◽  
Tumor Delineation ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
Image Quality Improvement ◽  
Fluorodeoxyglucose Positron Emission

Abstract Background Deep learning (DL)-based image quality improvement is a novel technique based on convolutional neural networks. The aim of this study was to compare the clinical value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) images obtained with the DL method with those obtained using a Gaussian filter. Methods Fifty patients with a mean age of 64.4 (range, 19–88) years who underwent 18F-FDG PET/CT between April 2019 and May 2019 were included in the study. PET images were obtained with the DL method in addition to conventional images reconstructed with three-dimensional time of flight-ordered subset expectation maximization and filtered with a Gaussian filter as a baseline for comparison. The reconstructed images were reviewed by two nuclear medicine physicians and scored from 1 (poor) to 5 (excellent) for tumor delineation, overall image quality, and image noise. For the semi-quantitative analysis, standardized uptake values in tumors and healthy tissues were compared between images obtained using the DL method and those obtained with a Gaussian filter. Results Images acquired using the DL method scored significantly higher for tumor delineation, overall image quality, and image noise compared to baseline (P < 0.001). The Fleiss’ kappa value for overall inter-reader agreement was 0.78. The standardized uptake values in tumor obtained by DL were significantly higher than those acquired using a Gaussian filter (P < 0.001). Conclusions Deep learning method improves the quality of PET images.

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