scholarly journals Investigation of Robustness of Radiomics Features Generated With Grey Level Co-occurrence Matrix (GLCM) for Positron Emission Tomography (PET) Image Analysis

2020 ◽  
Author(s):  
Mahbubunnabi Tamal
Keyword(s):  
Adaptive Threshold ◽  
Textural Features ◽  
Ct Scanner ◽  
Factors Affecting ◽  
Positron Emission ◽  
Intensity Information ◽  
Pet Ct ◽  
Fixed Threshold ◽  
Uniform Background ◽  
Occurrence Matrix

Abstract Background: Quantification of heterogeneous radiotracer uptake in PET has the potential to be used as a biomarker of prognosis. Textural features accounting for both spatial and intensity information have recently been applied to FDG-PET images and used to predict treatment response. However, textural features have been predicted to strongly depend on volume. Other factors affecting textural features such as segmentation and quantization have previously been investigated on clinical data while image contrast and noise have not been assessed systematically. This study aims to investigate the relationships between textural features and these factors using phantom data.Methods: The torso NEMA phantom was first filled with 18F solutions to yield different contrasts between the six hot spheres (0.5-27 cm3) and the colder uniform background (2:1, 4:1, 8:1) and scanned on the TrueV PET-CT scanner for 120min. Images were reconstructed using OSEM (4 iterations, 21 subsets) for different scan durations (15-120min) and smoothed with a 4-mm Gaussian filter. The phantom with two heterogeneous spherical inserts (8.2 and 18.8 cm3) was then scanned and reconstructed using same protocol for contrast 4:1 only. All spheres were delineated using three approaches 1) the exact boundaries based on their known diameters, 2) 40% fixed threshold and 3) adaptive threshold. Textural features were derived from the co-occurrence matrix using different quantization levels (8-256). Results: Some textural features (contrast, dissimilarity, entropy, correlation) increase while others (homogeneity, energy) decrease with quantization at different rates depending on sphere volume. When using the exact delineation, contrast and scan duration (noise) have a lesser effect on textural features than sphere volume. When applying the same exact regions on the uniform background (no partial volume), the relationships between textural features and volume are comparable to when applied to the respective spheres except for correlation. Textural features are indirectly related to noise and contrast via segmentation with adaptive threshold being superior compared to the fixed threshold. Conclusion:Among the six textural features, homogeneity and dissimilarity are the most suitable for measuring PET tumour heterogeneity with quantization 64 if regions are segmented using methods that are robust to noise and contrast variations. To use these textural features as prognostic biomarkers, changes in textural features between baseline and treatment scans should always be reported along with the changes in volumes.

scholarly journals A Phantom Study to Investigate Robustness and Reproducibility of Grey Level Co-Occurrence Matrix (GLCM)-Based Radiomics Features for PET

2021 ◽  
Vol 11 (2) ◽  
pp. 535
Author(s):  
Mahbubunnabi Tamal
Keyword(s):  
Textural Features ◽  
Strongly Correlated ◽  
Segmentation Method ◽  
Diagnosis And Prognosis ◽  
Radiotracer Uptake ◽  
Positron Emission ◽  
Occurrence Matrix ◽  
The Impact ◽  
Robust To Noise

Quantification and classification of heterogeneous radiotracer uptake in Positron Emission Tomography (PET) using textural features (termed as radiomics) and artificial intelligence (AI) has the potential to be used as a biomarker of diagnosis and prognosis. However, textural features have been predicted to be strongly correlated with volume, segmentation and quantization, while the impact of image contrast and noise has not been assessed systematically. Further continuous investigations are required to update the existing standardization initiatives. This study aimed to investigate the relationships between textural features and these factors with 18F filled torso NEMA phantom to yield different contrasts and reconstructed with different durations to represent varying levels of noise. The phantom was also scanned with heterogeneous spherical inserts fabricated with 3D printing technology. All spheres were delineated using: (1) the exact boundaries based on their known diameters; (2) 40% fixed; and (3) adaptive threshold. Six textural features were derived from the gray level co-occurrence matrix (GLCM) using different quantization levels. The results indicate that homogeneity and dissimilarity are the most suitable for measuring PET tumor heterogeneity with quantization 64 provided that the segmentation method is robust to noise and contrast variations. To use these textural features as prognostic biomarkers, changes in textural features between baseline and treatment scans should always be reported along with the changes in volumes.

Empfehlungen zur Durchführung der Ganz körper-18F-FDG-PET und -PET/CT bei Kindern mit onkologischen Erkrankungen

2010 ◽  
Vol 49 (06) ◽  
pp. 225-233 ◽  
Author(s):  
J. Stauss ◽  
T. Pfluger ◽  
K. U. Juergens ◽  
R. Kluge ◽  
H. Amthauer ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
Fdg Pet ◽  
German Society ◽  
Emission Tomography ◽  
Ct Scanner ◽  
High Radiation ◽  
Additional Information ◽  
Paediatric Committee ◽  
Positron Emission ◽  
Pet Ct

SummaryThe purpose of these guidelines is to offer the nuclear medicine and the appropriate interdisciplinary team a framework for performing and reporting positron emission tomography (PET) and the combination with computed tomography (PET/CT) in children with malignant diseases mainly using the radiopharmaceutical 18F-fluorodeoxy-glucose (FDG). These guidelines are based on the recent guidelines of the Paediatric Committee of the European Association of Nuclear Medicine (EANM) (57) and have been translated and adapted to the current conditions in Germany. The adaptation of CT-parameters using PET/CT in children is covered in a more detailed way than in the EANM guideline taking into account that in Germany already a good portion of PET examinations is performed using an integrated PET/CT-scanner. Furthermore, a CT-scan without adaption of the CT acquisition parameters would result in a not tolerably high radiation exposition of the child. There are excellent guidelines for FDG PET and PET/CT in oncology published by the German Society of Nuclear Medicine (Deutsche Gesellschaft für Nuklearmedizin, DGN) (42) and EANM (4). These guidelines aim at providing additional information on issues particularly relevant to PET and PET/CT imaging in children. These guidelines should be taken in the context of local and national current standards of quality and rules.

Discovery IQ by GE: Launching Super Value PET/CT Scanner

2018 ◽  
pp. 1-23
Author(s):  
Anand Kumar Jaiswal ◽  
Suresh Malodia
Keyword(s):  
Treatment Planning ◽  
Bottom Of The Pyramid ◽  
Ct Scanner ◽  
Financial Return ◽  
Market Strategy ◽  
Segmentation Strategy ◽  
Supply And Distribution ◽  
Tier Ii ◽  
Positron Emission ◽  
Pet Ct

It was mid-March 2014, and GE's John F. Welch Technology Centre in Bangalore, India was brimming with activity. GE had developed an advanced, scalable positron emission tomography-computed tomography (PET/CT) scanner as part of its global Healthymagination initiative to provide better healthcare for more people at a lower cost. Munesh Makhija, Managing Director, GE India Technology Centre and Chief Technology Officer (CTO), GE South Asia, was thumbing through a report prepared by the PET/CT product development team and GE's healthcare market research team. In another office, Suresh Kumar R.(Kumar), General Manager of the Essential PET Segment, was putting the finishing touches on a presentation outlining a commercialisation strategy for the new PET/CT product, Discovery IQ (Exhibit 1). Discovery IQ was a revolutionary product that would be useful for staging, treatment planning and post-treatment planning assessment. Early reviews from nuclear physicians had been positive. However, the product was still too costly for the bottom of the pyramid (BoP) market. Kumar and his team were scheduled to meet with Makhija the following morning to discuss a “go-to-market strategy”. Kumar knew that Makhija would want to talk about their segmentation strategy and the underlying needs of various customer types. He also expected Makhija to focus on return on investment (ROI) projections because diagnostic centres in India first looked at various financial return measures before investing in any new equipment. Kumar wanted to present a commercialisation strategy for Discovery IQ, which required a significant commitment of resources to tackle supply and distribution challenges across tier II and tier III citiesa in India.

scholarly journals THE USE OF SPECTRAL AND TEXTURAL FEATURES IN CROP TYPE MAPPING USING SENTINEL-2A IMAGES: A CASE STUDY, ÇUKUROVA REGION, TURKEY

2021 ◽  
Vol XLIII-B3-2021 ◽  
pp. 117-122
Author(s):  
A. Tuzcu Kokal ◽  
A. F. Sunar ◽  
A. Dervisoglu ◽  
S. Berberoglu
Keyword(s):  
Satellite Image ◽  
Support Vector ◽  
Textural Features ◽  
Factors Affecting ◽  
Object Based ◽  
Crop Types ◽  
Sentinel 2A ◽  
Occurrence Matrix ◽  
Agriculture Management ◽  
Sentinel 2

Abstract. Turkey has favorable agricultural conditions (i.e. fertile soils, climate and rainfall) and can grow almost any type of crop in many regions, making it one of the leading sectors of the economy. For sustainable agriculture management, all factors affecting the agricultural products should be analyzed on a spatial-temporal basis. Therefore, nowadays space technologies such as remote sensing are important tools in providing an accurate mapping of the agricultural fields with timely monitoring and higher repetition frequency and accuracy. In this study, object based classification method was applied to 2017 Sentinel 2 Level 2A satellite image in order to map crop types in the Adana, Çukurova region in Turkey. Support Vector Machine (SVM) was used as a classifier. Texture information were incorporated to spectral wavebands of Sentinel-2 image, to increase the classification accuracy. In this context, all of the textural features of Gray-Level Co-occurrence Matrix (GLCM) were tested and Entropy, Standard deviation, and Mean textural features were found to be the most suitable among them. Multi-spectral and textural features were used as an input separately and/or in combination to evaluate the potential of texture in differentiating crop types and the accuracy of output thematic maps. As a result, with the addition of textural features, it was observed that the Overall Accuracy and Kappa coefficient increased by 7% and 8%, respectively.

scholarly journals Machine Learning Facilitates Hotspot Classification in PSMA-PET/CT with Nuclear Medicine Specialist Accuracy

Diagnostics ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 622
Author(s):  
Sobhan Moazemi ◽  
Zain Khurshid ◽  
Annette Erle ◽  
Susanne Lütje ◽  
Markus Essler ◽  
...  
Keyword(s):  
Machine Learning ◽  
Positron Emission Tomography ◽  
Low Dose ◽  
Emission Tomography ◽  
Textural Features ◽  
Low Dose Ct ◽  
Positron Emission ◽  
Psma Pet ◽  
Pet Ct ◽  
Ct Data

Gallium-68 prostate-specific membrane antigen positron emission tomography (68Ga-PSMA-PET) is a highly sensitive method to detect prostate cancer (PC) metastases. Visual discrimination between malignant and physiologic/unspecific tracer accumulation by a nuclear medicine (NM) specialist is essential for image interpretation. In the future, automated machine learning (ML)-based tools will assist physicians in image analysis. The aim of this work was to develop a tool for analysis of 68Ga-PSMA-PET images and to compare its efficacy to that of human readers. Five different ML methods were compared and tested on multiple positron emission tomography/computed tomography (PET/CT) data-sets. Forty textural features extracted from both PET- and low-dose CT data were analyzed. In total, 2419 hotspots from 72 patients were included. Comparing results from human readers to those of ML-based analyses, up to 98% area under the curve (AUC), 94% sensitivity (SE), and 89% specificity (SP) were achieved. Interestingly, textural features assessed in native low-dose CT increased the accuracy significantly. Thus, ML based on 68Ga-PSMA-PET/CT radiomics features can classify hotspots with high precision, comparable to that of experienced NM physicians. Additionally, the superiority of multimodal ML-based analysis considering all PET and low-dose CT features was shown. Morphological features seemed to be of special additional importance even though they were extracted from native low-dose CTs.

scholarly journals Impact of the Noise Penalty Factor on Quantification in Bayesian Penalized Likelihood (Q.Clear) Reconstructions of 68Ga-PSMA PET/CT Scans

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 847
Author(s):  
Sjoerd Rijnsdorp ◽  
Mark J. Roef ◽  
Albert J. Arends
Keyword(s):  
Penalized Likelihood ◽  
Ct Scans ◽  
Ct Scanner ◽  
Scan Time ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
Penalty Factor ◽  
Psma Pet ◽  
Pet Ct ◽  
Voxel Grid

Functional imaging with 68Ga prostate-specific membrane antigen (PSMA) and positron emission tomography (PET) can fulfill an important role in treatment selection and adjustment in prostate cancer. This article focusses on quantitative assessment of 68Ga-PSMA-PET. The effect of various parameters on standardized uptake values (SUVs) is explored, and an optimal Bayesian penalized likelihood (BPL) reconstruction is suggested. PET acquisitions of two phantoms consisting of a background compartment and spheres with diameter 4 mm to 37 mm, both filled with solutions of 68Ga in water, were performed with a GE Discovery 710 PET/CT scanner. Recovery coefficients (RCs) in multiple reconstructions with varying noise penalty factors and acquisition times were determined and analyzed. Apparent recovery coefficients of spheres with a diameter smaller than 17 mm were significantly lower than those of spheres with a diameter of 17 mm and bigger (p < 0.001) for a tumor-to-background (T/B) ratio of 10:1 and a scan time of 10 min per bed position. With a T/B ratio of 10:1, the four largest spheres exhibit significantly higher RCs than those with a T/B ratio of 20:1 (p < 0.0001). For spheres with a diameter of 8 mm and less, alignment with the voxel grid potentially affects the RC. Evaluation of PET/CT scans using (semi-)quantitative measures such as SUVs should be performed with great caution, as SUVs are influenced by scanning and reconstruction parameters. Based on the evaluation of multiple reconstructions with different β of phantom scans, an intermediate β (600) is suggested as the optimal value for the reconstruction of clinical 68Ga-PSMA PET/CT scans, considering that both detectability and reproducibility are relevant.

scholarly journals PET-CT: Radiological signs in Sarcoidosis-Lymphoma Syndrome

2020 ◽  
pp. 45-50
Author(s):  
Brunela Ronchi ◽  
Gustavo Peña ◽  
Muriel Henriquez
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Clinical Case ◽  
Emission Tomography ◽  
Ct Scanner ◽  
X Ray ◽  
Positron Emission ◽  
Pet Ct ◽  
X Ray Computed ◽  
Complex Cases

Sarcoidosis-lymphoma syndrome is a clinical entity that can be diagnosed in different ways. Some of them are atypical. For these complex cases, positron emission tomography (PET) combined with an X-ray computed tomography (CT) scanner (PET-CT) is definitive for subsequent biopsy. A clinical case of our group is presented, which leads to the corresponding revision / update.

scholarly journals Results of a Prospective Trial to Compare 68Ga-DOTA-TATE with SiPM-Based PET/CT vs. Conventional PET/CT in Patients with Neuroendocrine Tumors

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 992
Author(s):  
Lucia Baratto ◽  
Akira Toriihara ◽  
Negin Hatami ◽  
Carina M. Aparici ◽  
Guido Davidzon ◽  
...  
Keyword(s):  
Neuroendocrine Tumors ◽  
Prospective Trial ◽  
Standardized Uptake Value ◽  
Superior Performance ◽  
Ct Scanner ◽  
Silicon Photomultiplier ◽  
Delayed Imaging ◽  
Positron Emission ◽  
Pet Ct ◽  
The Difference

We prospectively enrolled patients with neuroendocrine tumors (NETs). They underwent a single 68Ga-DOTA-TATE injection followed by dual imaging and were randomly scanned using first either the conventional or the silicon photomultiplier (SiPM) positron emission tomography/computed tomography (PET/CT), followed by imaging using the other system. A total of 94 patients, 44 men and 50 women, between 35 and 91 years old (mean ± SD: 63 ± 11.2), were enrolled. Fifty-two out of ninety-four participants underwent SiPM PET/CT first and a total of 162 lesions were detected using both scanners. Forty-two out of ninety-four participants underwent conventional PET/CT first and a total of 108 lesions were detected using both scanners. Regardless of whether SiPM-based PET/CT was used first or second, maximum standardized uptake value (SUVmax) of lesions measured on SiPM was on average 20% higher when comparing two scanners with all enrolled patients, and the difference was statistically significant. SiPM-based PET/CT detected 19 more lesions in 13 patients compared with conventional PET/CT. No lesions were only identified by conventional PET/CT. In conclusion, we observed higher SUVmax for lesions measured from SiPM PET/CT compared with conventional PET/CT regardless of the order of the scans. SiPM PET/CT allowed for identification of more lesions than conventional PET/CT. While delayed imaging can lead to higher SUVmax in cancer lesions, in the series of lesions identified when SiPM PET/CT was used first, this was not the case; therefore, the data suggest superior performance of the SiPM PET/CT scanner in visualizing and quantifying lesions.

scholarly journals Initial Experience with 64Cu-DOTATATE Digital PET of Patients with Neuroendocrine Neoplasms: Comparison with Analog PET

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 350
Author(s):  
Mathias Loft ◽  
Camilla B. Johnbeck ◽  
Esben A. Carlsen ◽  
Helle H. Johannesen ◽  
Peter Oturai ◽  
...  
Keyword(s):  
Emission Tomography ◽  
Acquisition Time ◽  
Neuroendocrine Neoplasms ◽  
Ct Scanner ◽  
Siemens Biograph ◽  
Positron Emission ◽  
Pet Ct ◽  
Digital Pet ◽  
Image Acquisition Time ◽  
Pet Scanners

The recent introduction of solid-state detectors in clinical positron emission tomography (PET) scanners has significantly improved image quality and spatial resolution and shortened acquisition time compared to conventional analog PET scanners. In an initial evaluation of the performance of our newly acquired Siemens Biograph Vision 600 PET/CT (digital PET/CT) scanner for 64Cu-DOTATATE imaging, we compared PET/CT acquisitions from patients with neuroendocrine neoplasms (NENs) grades 1 and 2 and stable disease on CT who were scanned on both our Siemens Biograph 128 mCT PET/CT (analog PET/CT) and digital PET/CT within 6 months as part of their routine clinical management. Five patients fulfilled the criteria and were included in the analysis. The digital PET acquisition time was less than 1/3 of the analog PET acquisition time (digital PET, mean (min:s): 08:20 (range, 07:59–09:45); analog PET, 25:28 (24:39–28:44), p < 0.001). All 44 lesions detected on the analog PET with corresponding structural correlates on the CT were also found on the digital PET performed 137 (107–176) days later. Our initial findings suggest that digital 64Cu-DOTATATE PET can successfully be performed in patients with NENs using an image acquisition time of only 1/3 of what is used for an analog 64Cu-DOTATATE PET.

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