scholarly journals A comparative analysis: international variation in PET-CT service provision in oncology—an International Cancer Benchmarking Partnership study

2020 ◽  
Author(s):  
Charlotte Lynch ◽  
Irene Reguilon ◽  
Deanna L Langer ◽  
Damon Lane ◽  
Prithwish De ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Service Provision ◽  
Data Capture ◽  
Clinical Indication ◽  
Position Emission Tomography ◽  
Inconsistent Data ◽  
Cancer Services ◽  
Pet Ct ◽  
The Impact

Abstract Objective To explore differences in position emission tomography-computed tomography (PET-CT) service provision internationally to further understand the impact variation may have upon cancer services. To identify areas of further exploration for researchers and policymakers to optimize PET-CT services and improve the quality of cancer services. Design Comparative analysis using data based on pre-defined PET-CT service metrics from PET-CT stakeholders across seven countries. This was further informed via document analysis of clinical indication guidance and expert consensus through round-table discussions of relevant PET-CT stakeholders. Descriptive comparative analyses were produced on use, capacity and indication guidance for PET-CT services between jurisdictions. Setting PET-CT services across 21 jurisdictions in seven countries (Australia, Denmark, Canada, Ireland, New Zealand, Norway and the UK). Participants None. Intervention(s) None. Main Outcome Measure(s) None. Results PET-CT service provision has grown over the period 2006–2017, but scale of increase in capacity and demand is variable. Clinical indication guidance varied across countries, particularly for small-cell lung cancer staging and the specific acknowledgement of gastric cancer within oesophagogastric cancers. There is limited and inconsistent data capture, coding, accessibility and availability of PET-CT activity across countries studied. Conclusions Variation in PET-CT scanner quantity, acquisition over time and guidance upon use exists internationally. There is a lack of routinely captured and accessible PET-CT data across the International Cancer Benchmarking Partnership countries due to inconsistent data definitions, data linkage issues, uncertain coverage of data and lack of specific coding. This is a barrier in improving the quality of PET-CT services globally. There needs to be greater, richer data capture of diagnostic and staging tools to facilitate learning of best practice and optimize cancer services.

Impact of total variation regularized expectation maximization reconstruction on the image quality of 68Ga-PSMA PET: a phantom and patient study

2021 ◽  
pp. 20201356
Author(s):  
Feng-Jiao Yang ◽  
Shu-Yue Ai ◽  
Runze Wu ◽  
Yang Lv ◽  
Hui-Fang Xie ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Image Quality ◽  
Total Variation ◽  
Expectation Maximization ◽  
Image Noise ◽  
Psma Pet ◽  
Pet Ct ◽  
Digital Pet ◽  
The Impact

Objectives: To investigate the impact of total variation regularized expectation maximization (TVREM) reconstruction on the image quality of 68Ga-PSMA-11 PET/CT using phantom and patient data. Methods: Images of a phantom with small hot sphere inserts and 20 prostate cancer patients were acquired with a digital PET/CT using list-mode and reconstructed with ordered subset expectation maximization (OSEM) and TVREM with seven penalisation factors between 0.01 and 0.42 for 2 and 3 minutes-per-bed (m/b) acquisition. The contrast recovery (CR) and background variability (BV) of the phantom, image noise of the liver, and SUVmax of the lesions were measured. Qualitative image quality was scored by two radiologists using a 5-point scale (1-poor, 5-excellent). Results: The performance of CR, BV, and image noise, and the gain of SUVmax was higher for TVREM 2 m/b groups with the penalization of 0.07 to 0.28 compared to OSEM 3 m/b group (all p < 0.05). The image noise of OSEM 3 m/b group was equivalent to TVREM 2 and 3 m/b groups with a penalization of 0.14 and 0.07, while lesions’ SUVmax increased 15 and 20%. The highest qualitative score was attained at the penalization of 0.21 (3.30 ± 0.66) for TVREM 2 m/b groups and the penalization 0.14 (3.80 ± 0.41) for 3 m/b group that equal to or greater than OSEM 3 m/b group (2.90 ± 0.45, p = 0.2 and p < 0.001). Conclusions: TVREM improves lesion contrast and reduces image noise, which allows shorter acquisition with preserved image quality for PSMA PET/CT. Advances in knowledge: TVREM reconstruction with optimized penalization factors can generate higher quality PSMA-PET images for prostate cancer diagnosis.

The impact on diagnostic quality of using contrast media in PET-CT studies

2010 ◽  
Vol 52 (4) ◽  
pp. 327-332
Author(s):  
M. García García-Esquinas ◽  
A. Ortega Candil ◽  
L. Lapeña Gutierrez ◽  
J. Mucientes Rasilla ◽  
J.L. Carreras Delgado ◽  
...  
Keyword(s):  
Contrast Media ◽  
Diagnostic Quality ◽  
Pet Ct ◽  
The Impact ◽  
Ct Studies

Impact of 18F-fluorodeoxyglucose position emission tomography/computed tomography on radiotherapy treatment planning and outcomes in esophageal cancer.

2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 67-67
Author(s):  
Sweet Ping Ng ◽  
Jennifer Tan ◽  
Glen Osbourne ◽  
Luke Williams ◽  
Mathias Bressel ◽  
...  
Keyword(s):  
Overall Survival ◽  
Esophageal Cancer ◽  
Survival Rates ◽  
Ct Scanning ◽  
Radiotherapy Planning ◽  
Position Emission Tomography ◽  
Pet Ct ◽  
Ct Data ◽  
The Impact ◽  
Radiotherapy Treatment

67 Background: Currently there is no universally accepted method to accurately delineate the gross tumor volume (GTV) of primary esophageal cancer in patients undergoing radiotherapy. This prospective study aims to determine the impact of PET/CT on radiotherapy planning and outcomes in patients with localized esophageal cancer. Methods: 54 patients were recruited between June 2003 - May 2008. All underwent PET/CT scanning in the radiotherapy treatment position and received treatment planned using the PET/CT dataset. Of these, 13 (24.1%) had metastatic disease detected on PET and 3 patients had no radical radiotherapy, while another 3 patients had missing planning PET/CT data (excluded from planning component analysis). GTV was defined separately on PET/CT (GTV-PET) and CT (GTV-CT) data sets. A corresponding planning target volume (PTV) was generated for each patient. Volumetric and spatial analysis quantified the proportion of FDG-avid disease not included in CT-based volumes. Clinical data was collected for 38 patients treated radically to determine locoregional control and overall survival rates. Results: Mean age was 67 years (range:32 - 88). Median follow up was 4 years (range:2.7 – 6.8). FDG-avid disease would have been excluded from GTV-CT in 29 patients (79%) with a mean volume of 17% (range:1-100%). In 5 patients, FDG-avid disease would have been completely excluded from the PTV-CT (median volume missed = 6%, range:2-92%). For 8 patients, less than 95% of PTV-PET would have received at least 95% of prescription dose based on the CT-based plan. GTV-CT underestimated the cranial and caudal extent of FDG-avid tumor in 14 (36%) and 10 (26%) patients respectively. There were no significant differences in radiation doses to the lungs and liver. 5-year overall survival and locoregional failure free survival were 24%, and 42% respectively. Conclusions: PET/CT prevented futile radiotherapy for 1 in 4 patients and avoided geographic misses without significant impact on normal tissues in apparently localized esophageal cancer. However, survival remains suboptimal and indicates the need for further improvement in planning and therapeutic paradigms.

Prediction of perioperative parameters of laparoscopic organ-sparing interventions on the kidney taking into account the surgeon's "learning curve"

2021 ◽  
Author(s):  
V.N. Gridin ◽  
I.A. Kuznetsov ◽  
A.I. Gazov ◽  
E.S. Sirota
Keyword(s):  
Logistic Regression ◽  
Comparative Analysis ◽  
Learning Curve ◽  
Multilayer Perceptron ◽  
Regression Line ◽  
Integrated Approach ◽  
Duration Of Surgery ◽  
Surgical Tactics ◽  
The Impact

The paper considers an integrated approach for constructing models for predicting the perioperative parameters of laparoscopic kidney resections, which include the duration of the operation, the time of thermal ischemia, and the glomerular filtration rate 24 hours after the operation. The approach is based on the principle of expanding the feature space, extracted from the analysis of the surgeon's "learning curve" data when mastering laparoscopic kidney resections. The aim of this work is to predict the main perioperative parameters that have the most significant impact on the surgical tactics of treatment at the stage of planning surgery. New methods have been developed for identifying significant parameters that take into account the complexity of the operation and the qualifications of the surgeon based on his “learning curve”. The parameters to be distinguished include: “complexity of the operation” based on nephrometric indices (RENAL, PADUA and C-index); the average value of the predicted perioperative parameters of surgical interventions depending on the complexity; slope and standard error based on the regression line of predicted perioperative parameters. Models were developed for predicting the perioperative parameters of laparoscopic organ-preserving kidney interventions using modern approaches based on machine learning, which are based on the algorithms “decision trees”, “multilayer perceptron”, “Naïve Bayes”, “logistic regression”. A comparative analysis of the quality of the developed models was carried out, as a result of which the best result was obtained using the “logistic regression” algorithm. The F-measure was used as a metric. A comparative analysis of the developed models was carried out to assess the impact on the final quality of the new selected features. For the predicted parameter “time of thermal ischemia” the increase was from 9.68% to 16.68%; for the predicted parameter “duration of surgery” the increase was from 2.76% to 4.08%. At the same time, for the predicted parameter “GFR in 24 hours” there was no significant increase, and for the “multilayer perceptron” algorithm it turned out to be negative. The obtained forecasting models can be used in applied software solutions that act as decision support systems in determining the surgical tactics of treating patients with localized formations of the renal parenchyma. Such software solutions can be implemented as a web service or as a separate program.

Environmental Quality of Impact Drills

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Beata Hricová ◽  
Ervin Lumnitzer
Keyword(s):  
Life Cycle ◽  
Comparative Analysis ◽  
Environmental Impact ◽  
Environmental Quality ◽  
Environmental Performance ◽  
Analysis Method ◽  
Technical Parameters ◽  
Production Stage ◽  
The Impact

AbstractEnvironmental performance of each product is defined already at the stage of its design - in its pre-production stage. Environmental quality of the product is one of the most important factors of environmental performance of a product. Environmental quality includes a range of criteria that indicate the nature of the product and its environmental impact throughout its life cycle. The comparative analysis method is one of the ways to assess the environmental quality of the product. The article gives a specific example of the assessments carried out on the impact drills (of one specific brand) with different technical parameters.

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 Comparison of Image Quality and Spatial Resolution Between 18F, 68Ga and 64Cu Phantom Measurements Using a Digital Biograph Vision PET/CT

2022 ◽  
Author(s):  
Anja Braune ◽  
Liane Oehme ◽  
Robert Freudenberg ◽  
Frank Hofheinz ◽  
Jörg van den Hoff ◽  
...  
Keyword(s):  
Image Quality ◽  
Spatial Resolution ◽  
Ct Scans ◽  
Reconstruction Method ◽  
Recovery Coefficient ◽  
Positron Energy ◽  
Pet Ct ◽  
The Individual ◽  
The Impact

Abstract Background: The PET nuclide and reconstruction method can have a considerable influence on spatial resolution and image quality of PET/CT scans, which can, for example, influence the diagnosis in oncology. The individual impact of the positron energy of 18F, 68Ga and 64Cu on spatial resolution and image quality of PET/CT scans acquired using a clinical, digital scanner was compared. Furthermore, the impact of different reconstruction parameters on image quality and spatial resolution was evaluated for 18F-FDG PET/CT scans acquired with a scanner of the newest generation. Methods: PET/CT scans of a Jaszczak phantom and a NEMA PET body phantom, filled with 18F-FDG, 68Ga-HCl and 64Cu-HCl, respectively, were performed on a Siemens Biograph Vision. Images were assessed using spatial resolution and image quality (Recovery Coefficients (RC), coefficient of variation within the background, Contrast Recovery Coefficient (CRC), Contrast-Noise-Ratio (CNR), and relative count error in lung insert). In a subsequent analysis, the scan of the NEMA PET body phantom filled with 18F-FDG was reconstructed applying different parameters (with/without the application of Point Spread Function (PSF), Time of Flight (ToF) or post-filtering; matrix size). Spatial resolution and quantitative image quality were compared between reconstructions. Results: We found that image quality was comparable between 18F-FDG and 64Cu-HCl PET/CT measurements featuring similar maximal endpoint energy. In comparison, RC, CRC and CNR were worse in 68Ga-HCl data, despite similar count rates. Spatial resolution was up to 18 % worse in 68Ga-HCl compared to 18F-FDG images. Post-filtering of 18F-FDG acquisitions changed image quality the most and reduced spatial resolution by 52 % if a Gaussian filter with 5 mm FWHM was applied. ToF measurements especially improved the recovery of the smallest lesion (RCmean = 1.07 compared to 0.65 without ToF) and improved spatial resolution by 29 %.Conclusions: The positron energy of PET nuclides influences spatial resolution and image quality of digital PET/CT scans. Image quality of 68Ga-HCl PET/CT images was worse compared to 18F-FDG and 64Cu-HCl, respectively, despite similar count rates. Reconstruction parameters have a high impact on image quality and spatial resolution and should be considered when comparing images of different scanners or centers.

scholarly journals IMPROVING THE DURABILITY OF CULTIVATOR BLADES USING ONE-SIDED GAS-FLAME SURFACING

2020 ◽  
pp. 1-11
Author(s):  
Azamat Fayurshin ◽  
Mars Farkhshatov ◽  
Rinat Saifullin ◽  
Linar Islamov ◽  
Ilnar Gaskarov ◽  
...  
Keyword(s):  
Composite Material ◽  
Comparative Analysis ◽  
Wear Resistant Coatings ◽  
Foreign Experience ◽  
Application Methods ◽  
Gas Flame ◽  
The One ◽  
Agar Production ◽  
The Impact

In agar production one of the most common technological operations is cutting of soil or plants. It makes up at least 70% of the total volume of mechanized works. The purpose of this study is to help maintain the agrotechnological parameters of the cultivator's blade by coating the blade with powder wear-resistant coatings using the one-sided gas-flame surfacing technology. The technology of strengthening the cultivator blade using one-sided gas-flame surfacing is applied. As a result, were defined: powder granulation on the thickness of the applied layer; modes and parameters of the one-sided gas-flame surfacing during the formation of composite material coating. Foreign experience of the last decades shows that with the development of gasometric spraying methods it is possible to atomize various materials such as polymers, carbides, metals. These coatings withstand the impact of high thermal loads, shock-abrasive and chemically active environments. Comparison of application methods mentioned above shows that the quality of coatings expressed in the parameters: adhesions, porosity, oxidation levels remain at approximately the same level. However, a comparative analysis of foreign practice has shown that the method of gas-flame surfacing is more technological, more productivity, and the specific costs of the coating are reduced.

scholarly journals IMPACT OF ACCREDITATION OF TEACHER EDUCATION PROGRAMS IN PAKISTAN ON PROSPECTIVE TEACHERS`LEARNING; A COMPARATIVE STUDY

2021 ◽  
Vol 4 (3) ◽  
Author(s):  
Tasneem Saifuddin
Keyword(s):  
Teacher Education ◽  
Comparative Analysis ◽  
Prospective Teachers ◽  
Teacher Education Program ◽  
Quality Criteria ◽  
Accreditation Process ◽  
Teacher Education Programs ◽  
Education Programs ◽  
The Impact

The world is recently moving towards quality criteria in every field. For this Accreditation process has been introduced in every Discipline, Institute and Program to maintain the standards of quality. Accreditation refers to the authenticity and fairness in achieving the benchmarks of standards of program, a course, a module or an Institution. (Harvey, 2004). Accreditation provides certainty that the course or program will meet the demands and requirements of the quality standards. In order to produce trained professionals’ quality in higher education is required and Accreditation process will provide the Quality Assurance. As the teachers are the roots of every profession, therefore the Accreditation Process is also introduced in the field of teacher Education Program to maintain and improve the quality of Teacher Education Programs. When talking in context of Pakistan, there is always an issue regarding in quality of Education in Pakistan. In order to meet this demand NACTE (National Accreditation Council for Teacher Education) is established so that the quality criteria can be achieved through the process of Accreditation of different Teacher Education Programs in Pakistan. (Shakoor, & Farrukh, 2016). The programs or courses having NACTE Accredited certificate can be accepted globally and thus can serves as a basis of good professional start. The present study aims to find out the comparative analysis of the impacts of NACTE Accredited and Non-Accredited Teacher Education Programs on student's Achievement. The study is conducted on students of B. Ed honors studying in different institutions in Karachi. To carry out comparative analysis MGA (Multigroup Analysis) is carried out on Smart PLS: 3. The analysis done revealed high ‘values of Accredited groups as compared to nonAccredited groups, concluding that there are significant differences in the impact of two types of programs; Accredited and Non-Accredited teacher Education Programs on student teacher`s achievement. The results declared that Accredited Programs

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