Pub Date : 2024-09-09DOI: 10.1088/2057-1976/ad7593
Behzad Ebrahimi
Objectives. This study investigates the association between cerebral blood flow (CBF) and overall survival (OS) in glioblastoma multiforme (GBM) patients receiving chemoradiation. Identifying CBF biomarkers could help predict patient response to this treatment, facilitating the development of personalized therapeutic strategies.Materials and Methods. This retrospective study analyzed CBF data from dynamic susceptibility contrast (DSC) MRI in 30 newly diagnosed GBM patients (WHO grade IV). Radiomics features were extracted from CBF maps, tested for robustness, and correlated with OS. Kaplan-Meier analysis was used to assess the predictive value of radiomic features significantly associated with OS, aiming to stratify patients into groups with distinct post-treatment survival outcomes.Results. While mean relative CBF and CBV failed to serve as independent prognostic markers for OS, the prognostic potential of radiomic features extracted from CBF maps was explored. Ten out of forty-three radiomic features with highest intraclass correlation coefficients (ICC > 0.9), were selected for characterization. While Correlation and Zone Size Variance (ZSV) features showed significant OS correlations, indicating prognostic potential, Kaplan-Meier analysis did not significantly stratify patients based on these features. Visual analysis of the graphs revealed a predominant association between the identified radiomic features and OS under two years. Focusing on this subgroup, Correlation, ZSV, and Gray-Level Nonuniformity (GLN) emerged as significant, suggesting that a lack of heterogeneity in perfusion patterns may be indicative of a poorer outcome. Kaplan-Meier analysis effectively stratified this cohort based on the features mentioned above. Receiver operating characteristic (ROC) analysis further validated their prognostic value, with ZSV demonstrating the highest sensitivity and specificity (0.75 and 0.85, respectively).Conclusion. Our findings underscored radiomics features sensitive to CBF heterogeneity as pivotal predictors for patient stratification. Our results suggest that these markers may have the potential to identify patients who are unlikely to benefit from standard chemoradiation therapy.
研究目的本研究探讨了接受化疗的多形性胶质母细胞瘤(GBM)患者脑血流(CBF)与总生存期(OS)之间的关系。确定CBF生物标志物有助于预测患者对这种治疗的反应,从而促进个性化治疗策略的开发:这项回顾性研究分析了 30 名新确诊的 GBM 患者(WHO IV 级)的动态易感对比(DSC)磁共振成像的 CBF 数据。从CBF图中提取放射组学特征,测试其稳健性,并将其与OS相关联。采用卡普兰-梅耶尔分析评估与OS显著相关的放射组学特征的预测价值,旨在将患者分为具有不同治疗后生存结果的组别:结果:虽然平均相对 CBF 和 CBV 未能作为 OS 的独立预后指标,但研究人员探索了从 CBF 图中提取的放射学特征的预后潜力。在 43 个具有最高类内相关系数(ICC > 0.9)的放射学特征中,有 10 个被选中进行特征描述。虽然相关性和区域大小方差(ZSV)特征显示出显著的 OS 相关性,表明了预后潜力,但 Kaplan-Meier 分析并未根据这些特征对患者进行显著分层。对图表的直观分析显示,已确定的放射学特征与两年以下的OS之间存在主要关联。针对这一亚组,相关性、ZSV 和灰阶不均匀性(GLN)具有重要意义,表明灌注模式缺乏异质性可能预示着较差的预后。卡普兰-梅耶尔分析根据上述特征对该队列进行了有效的分层。接收者操作特征(ROC)分析进一步验证了这些特征的预后价值,其中ZSV的敏感性和特异性最高(分别为0.75和0.85):我们的研究结果表明,对CBF异质性敏感的放射组学特征是对患者进行分层的关键预测指标。我们的研究结果表明,这些标记物有可能鉴别出那些不太可能从标准化学放疗中获益的患者。
{"title":"Radiomics analysis of cerebral blood flow suggests a possible link between perfusion homogeneity and poor glioblastoma multiforme prognosis.","authors":"Behzad Ebrahimi","doi":"10.1088/2057-1976/ad7593","DOIUrl":"10.1088/2057-1976/ad7593","url":null,"abstract":"<p><p><i>Objectives</i>. This study investigates the association between cerebral blood flow (CBF) and overall survival (OS) in glioblastoma multiforme (GBM) patients receiving chemoradiation. Identifying CBF biomarkers could help predict patient response to this treatment, facilitating the development of personalized therapeutic strategies.<i>Materials and Methods</i>. This retrospective study analyzed CBF data from dynamic susceptibility contrast (DSC) MRI in 30 newly diagnosed GBM patients (WHO grade IV). Radiomics features were extracted from CBF maps, tested for robustness, and correlated with OS. Kaplan-Meier analysis was used to assess the predictive value of radiomic features significantly associated with OS, aiming to stratify patients into groups with distinct post-treatment survival outcomes.<i>Results</i>. While mean relative CBF and CBV failed to serve as independent prognostic markers for OS, the prognostic potential of radiomic features extracted from CBF maps was explored. Ten out of forty-three radiomic features with highest intraclass correlation coefficients (ICC > 0.9), were selected for characterization. While Correlation and Zone Size Variance (ZSV) features showed significant OS correlations, indicating prognostic potential, Kaplan-Meier analysis did not significantly stratify patients based on these features. Visual analysis of the graphs revealed a predominant association between the identified radiomic features and OS under two years. Focusing on this subgroup, Correlation, ZSV, and Gray-Level Nonuniformity (GLN) emerged as significant, suggesting that a lack of heterogeneity in perfusion patterns may be indicative of a poorer outcome. Kaplan-Meier analysis effectively stratified this cohort based on the features mentioned above. Receiver operating characteristic (ROC) analysis further validated their prognostic value, with ZSV demonstrating the highest sensitivity and specificity (0.75 and 0.85, respectively).<i>Conclusion</i>. Our findings underscored radiomics features sensitive to CBF heterogeneity as pivotal predictors for patient stratification. Our results suggest that these markers may have the potential to identify patients who are unlikely to benefit from standard chemoradiation therapy.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142103983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1088/2057-1976/ad785e
Subitcha Jayasankar,N Sujatha
The heterogeneity, non-uniform nature, and ethical concerns in sourcing biological tissues pose several challenges to designing, calibrating, standardizing, and evaluating the performance of spectroscopy-based diagnostic methods. A synthetic phantom module that can resemble a multi-layered tissue structure while including multiple tissue biomarkers with long-shelf life and stability is vital to overcome these challenges. This work uses a multi-layered silicone phantom to incorporate multiple biomarkers suitable for multi-modal spectroscopy testing and calibration. The phantom mimics the microcalcification distribution in the breast tissues using hydroxyapatite and the endogenous fluorescence seen in the tissues using Flavin Adenine Dinucleotide (FAD) and Nicotinamide Adenine Dinucleotide (NADH). The utility of this phantom for tumor margin analysis is analyzed using Diffuse reflectance, fluorescence, and Raman spectroscopy. The observed relative differences in intensity with changes in the silicone tumor layer depth and thickness are suitable for instrument calibration and fiber-optic probe design for tumor margin analysis.
.
{"title":"Multi-layered silicone-based breast tissue phantom for multi-modal optical spectroscopy.","authors":"Subitcha Jayasankar,N Sujatha","doi":"10.1088/2057-1976/ad785e","DOIUrl":"https://doi.org/10.1088/2057-1976/ad785e","url":null,"abstract":"The heterogeneity, non-uniform nature, and ethical concerns in sourcing biological tissues pose several challenges to designing, calibrating, standardizing, and evaluating the performance of spectroscopy-based diagnostic methods. A synthetic phantom module that can resemble a multi-layered tissue structure while including multiple tissue biomarkers with long-shelf life and stability is vital to overcome these challenges. This work uses a multi-layered silicone phantom to incorporate multiple biomarkers suitable for multi-modal spectroscopy testing and calibration. The phantom mimics the microcalcification distribution in the breast tissues using hydroxyapatite and the endogenous fluorescence seen in the tissues using Flavin Adenine Dinucleotide (FAD) and Nicotinamide Adenine Dinucleotide (NADH). The utility of this phantom for tumor margin analysis is analyzed using Diffuse reflectance, fluorescence, and Raman spectroscopy. The observed relative differences in intensity with changes in the silicone tumor layer depth and thickness are suitable for instrument calibration and fiber-optic probe design for tumor margin analysis.
.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1088/2057-1976/ad7598
Mojtaba Mokari, Hossein Moeini and Mina Eslamifar
Living tissues could suffer different types of DNA damage as a result of being exposed to ionizing radiations. Monte Carlo simulations of the underlying interactions have been instrumental in predicting the damage types and the processes involved. In this work, we employed Geant4-DNA and MCDS for extracting the initial DNA damage and investigating the dependence of damage efficiency on the cell’s oxygen content. The frequency-mean lineal ( ) and specific ( ) energies were derived for a spherical volume of water of various diameters between 2 and 11.1 μm. This sphere would serve as the nucleus of a cell of 100 μm diameter, engulfed by a homogeneous beam of protons. These microdosimetric quantities were calculated assuming spherical samples of 1 μm diameter in MCDS. The simulation results showed that for 230 MeV protons, an increase in the oxygen content from 0 by 10% raised the frequency of single- and double-strand breaks and lowered the base damage frequency. The resulting damage frequencies appeared to be independent of nucleus diameter. For proton energies between 2 and 230 MeV, showed no dependence on the cell diameter and an increase of the cell size resulted in a decrease in An increase in the proton energy slowed down the decreasing rate of as a function of nucleus diameter. However, the ratio of values corresponding to two proton energies of choice showed no dependence on the nucleus size and were equal to the ratio of the corresponding values. Furthermore, the oxygen content of the cell did not affect these microdosimetric quantities. Contrary to damage frequencies, these quantities appeared to depend only on direct interactions due to deposited energies. Our calculations showed the near independence of DNA damages on the nucleus size of the human cells. The probabilities of different types of single and double-strand breaks increase with the oxygen content.
{"title":"Monte Carlo investigation of the nucleus size effect and cell’s oxygen content on the damage efficiency of protons","authors":"Mojtaba Mokari, Hossein Moeini and Mina Eslamifar","doi":"10.1088/2057-1976/ad7598","DOIUrl":"https://doi.org/10.1088/2057-1976/ad7598","url":null,"abstract":"Living tissues could suffer different types of DNA damage as a result of being exposed to ionizing radiations. Monte Carlo simulations of the underlying interactions have been instrumental in predicting the damage types and the processes involved. In this work, we employed Geant4-DNA and MCDS for extracting the initial DNA damage and investigating the dependence of damage efficiency on the cell’s oxygen content. The frequency-mean lineal ( ) and specific ( ) energies were derived for a spherical volume of water of various diameters between 2 and 11.1 μm. This sphere would serve as the nucleus of a cell of 100 μm diameter, engulfed by a homogeneous beam of protons. These microdosimetric quantities were calculated assuming spherical samples of 1 μm diameter in MCDS. The simulation results showed that for 230 MeV protons, an increase in the oxygen content from 0 by 10% raised the frequency of single- and double-strand breaks and lowered the base damage frequency. The resulting damage frequencies appeared to be independent of nucleus diameter. For proton energies between 2 and 230 MeV, showed no dependence on the cell diameter and an increase of the cell size resulted in a decrease in An increase in the proton energy slowed down the decreasing rate of as a function of nucleus diameter. However, the ratio of values corresponding to two proton energies of choice showed no dependence on the nucleus size and were equal to the ratio of the corresponding values. Furthermore, the oxygen content of the cell did not affect these microdosimetric quantities. Contrary to damage frequencies, these quantities appeared to depend only on direct interactions due to deposited energies. Our calculations showed the near independence of DNA damages on the nucleus size of the human cells. The probabilities of different types of single and double-strand breaks increase with the oxygen content.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1088/2057-1976/ad7268
Henrik Finsberg, Verena Charwat, Kevin E Healy, Samuel T Wall
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are an effective tool for studying cardiac function and disease, and hold promise for screening drug effects on human tissue. Understanding alterations in motion patterns within these cells is crucial for comprehending how the administration of a drug or the onset of a disease can impact the rhythm of the human heart. However, quantifying motion accurately and efficiently from optical measurements using microscopy is currently time consuming. In this work, we present a unified framework for performing motion analysis on a sequence of microscopically obtained images of tissues consisting of hiPSC-CMs. We provide validation of our developed software using a synthetic test case and show how it can be used to extract displacements and velocities in hiPSC-CM microtissues. Finally, we show how to apply the framework to quantify the effect of an inotropic compound. The described software system is distributed as a python package that is easy to install, well tested and can be integrated into any python workflow.
{"title":"Automatic motion estimation with applications to hiPSC-CMs.","authors":"Henrik Finsberg, Verena Charwat, Kevin E Healy, Samuel T Wall","doi":"10.1088/2057-1976/ad7268","DOIUrl":"10.1088/2057-1976/ad7268","url":null,"abstract":"<p><p>Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are an effective tool for studying cardiac function and disease, and hold promise for screening drug effects on human tissue. Understanding alterations in motion patterns within these cells is crucial for comprehending how the administration of a drug or the onset of a disease can impact the rhythm of the human heart. However, quantifying motion accurately and efficiently from optical measurements using microscopy is currently time consuming. In this work, we present a unified framework for performing motion analysis on a sequence of microscopically obtained images of tissues consisting of hiPSC-CMs. We provide validation of our developed software using a synthetic test case and show how it can be used to extract displacements and velocities in hiPSC-CM microtissues. Finally, we show how to apply the framework to quantify the effect of an inotropic compound. The described software system is distributed as a python package that is easy to install, well tested and can be integrated into any python workflow.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1088/2057-1976/ad7267
Chayarat Wangweera, Plinio Zanini
Diabetic retinopathy (DR) is one of the leading causes of vision loss in adults and is one of the detrimental side effects of the mass prevalence of Diabetes Mellitus (DM). It is crucial to have an efficient screening method for early diagnosis of DR to prevent vision loss. This paper compares and analyzes the various Machine Learning (ML) techniques, from traditional ML to advanced Deep Learning models. We compared and analyzed the efficacy of Convolutional Neural Networks (CNNs), Capsule Networks (CapsNet), K-Nearest Neighbor (KNN), Support Vector Machine (SVM), decision trees, and Random Forests. This paper also considers determining factors in the evaluation, including contrast enhancements, noise reduction, grayscaling, etc We analyze recent research studies and compare methodologies and metrics, including accuracy, precision, sensitivity, and specificity. The findings highlight the advanced performance of Deep Learning (DL) models, with CapsNet achieving a remarkable accuracy of up to 97.98% and a high precision rate, outperforming other traditional ML methods. The Contrast Limited Adaptive Histogram Equalization (CLAHE) preprocessing technique substantially enhanced the model's efficiency. Each ML method's computational requirements are also considered. While most advanced deep learning methods performed better according to the metrics, they are more computationally complex, requiring more resources and data input. We also discussed how datasets like MESSIDOR could be more straightforward and contribute to highly evaluated performance and that there is a lack of consistency regarding benchmark datasets across papers in the field. Using the DL models facilitates accurate early detection for DR screening, can potentially reduce vision loss risks, and improves accessibility and cost-efficiency of eye screening. Further research is recommended to extend our findings by building models with public datasets, experimenting with ensembles of DL and traditional ML models, and considering testing high-performing models like CapsNet.
糖尿病视网膜病变(DR)是导致成人视力丧失的主要原因之一,也是糖尿病(DM)大规模流行的有害副作用之一。有效的筛查方法对早期诊断 DR 以防止视力丧失至关重要。本文比较并分析了从传统机器学习(ML)到高级深度学习模型的各种机器学习(ML)技术。我们比较并分析了卷积神经网络(CNN)、胶囊网络(CapsNet)、K-近邻(KNN)、支持向量机(SVM)、决策树和随机森林的功效。本文还考虑了评估中的决定性因素,包括对比度增强、降噪、灰度缩放等。我们分析了近期的研究,并比较了各种方法和指标,包括准确度、精确度、灵敏度和特异性。研究结果凸显了深度学习(DL)模型的先进性能,CapsNet 实现了高达 97.98% 的显著准确率和高精确率,优于其他传统 ML 方法。对比度受限自适应直方图均衡化(CLAHE)预处理技术大大提高了模型的效率。此外,还考虑了每种 ML 方法的计算要求。虽然大多数先进的深度学习方法在指标上表现更好,但它们在计算上更加复杂,需要更多的资源和数据输入。我们还讨论了像 MESSIDOR 这样的数据集如何能更简单明了地提高性能评估,以及该领域的论文在基准数据集方面缺乏一致性的问题。使用 DL 模型有助于对 DR 筛查进行准确的早期检测,有可能降低视力损失风险,并提高眼科筛查的可及性和成本效益。我们建议开展进一步的研究,通过使用公共数据集建立模型、尝试使用 DL 模型和传统 ML 模型的组合以及考虑测试 CapsNet 等高性能模型来扩展我们的研究结果。
{"title":"Comparison review of image classification techniques for early diagnosis of diabetic retinopathy.","authors":"Chayarat Wangweera, Plinio Zanini","doi":"10.1088/2057-1976/ad7267","DOIUrl":"10.1088/2057-1976/ad7267","url":null,"abstract":"<p><p>Diabetic retinopathy (DR) is one of the leading causes of vision loss in adults and is one of the detrimental side effects of the mass prevalence of Diabetes Mellitus (DM). It is crucial to have an efficient screening method for early diagnosis of DR to prevent vision loss. This paper compares and analyzes the various Machine Learning (ML) techniques, from traditional ML to advanced Deep Learning models. We compared and analyzed the efficacy of Convolutional Neural Networks (CNNs), Capsule Networks (CapsNet), K-Nearest Neighbor (KNN), Support Vector Machine (SVM), decision trees, and Random Forests. This paper also considers determining factors in the evaluation, including contrast enhancements, noise reduction, grayscaling, etc We analyze recent research studies and compare methodologies and metrics, including accuracy, precision, sensitivity, and specificity. The findings highlight the advanced performance of Deep Learning (DL) models, with CapsNet achieving a remarkable accuracy of up to 97.98% and a high precision rate, outperforming other traditional ML methods. The Contrast Limited Adaptive Histogram Equalization (CLAHE) preprocessing technique substantially enhanced the model's efficiency. Each ML method's computational requirements are also considered. While most advanced deep learning methods performed better according to the metrics, they are more computationally complex, requiring more resources and data input. We also discussed how datasets like MESSIDOR could be more straightforward and contribute to highly evaluated performance and that there is a lack of consistency regarding benchmark datasets across papers in the field. Using the DL models facilitates accurate early detection for DR screening, can potentially reduce vision loss risks, and improves accessibility and cost-efficiency of eye screening. Further research is recommended to extend our findings by building models with public datasets, experimenting with ensembles of DL and traditional ML models, and considering testing high-performing models like CapsNet.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1088/2057-1976/ad6f95
Mariana Bento, Hannah Cook, Virginia Marin Anaya, Esther Bär, Andrew Nisbet, Ana Lourenço, Mohammad Hussein, Catarina Veiga
Objective.To investigate the potential of 3D-printable thermoplastics as tissue-equivalent materials to be used in multimodal radiotherapy end-to-end quality assurance (QA) devices.Approach.Six thermoplastics were investigated: Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate Glycol (PETG), Polymethyl Methacrylate (PMMA), High Impact Polystyrene (HIPS) and StoneFil. Measurements of mass density (ρ), Relative Electron Density (RED), in a nominal 6 MV photon beam, and Relative Stopping Power (RSP), in a 210 MeV proton pencil-beam, were performed. Average Hounsfield Units (HU) were derived from CTs acquired with two independent scanners. The calibration curves of both scanners were used to predict averageρ,RED and RSP values and compared against the experimental data. Finally, measured data ofρ,RED and RSP was compared against theoretical values estimated for the thermoplastic materials and biological tissues.Main results.Overall, goodρand RSP CT predictions were made; only PMMA and PETG showed differences >5%. The differences between experimental and CT predicted RED values were also <5% for PLA, ABS, PETG and PMMA; for HIPS and StoneFil higher differences were found (6.94% and 9.42/15.34%, respectively). Small HU variations were obtained in the CTs for all materials indicating good uniform density distribution in the samples production. ABS, PLA, PETG and PMMA showed potential equivalency for a variety of soft tissues (adipose tissue, skeletal muscle, brain and lung tissues, differences within 0.19%-8.35% for all properties). StoneFil was the closest substitute to bone, but differences were >10%. Theoretical calculations of all properties agreed with experimental values within 5% difference for most thermoplastics.Significance.Several 3D-printed thermoplastics were promising tissue-equivalent materials to be used in devices for end-to-end multimodal radiotherapy QA and may not require corrections in treatment planning systems' dose calculations. Theoretical calculations showed promise in identifying thermoplastics matching target biological tissues before experiments are performed.
{"title":"Characterisation of 3D-printable thermoplastics to be used as tissue-equivalent materials in photon and proton beam radiotherapy end-to-end quality assurance devices.","authors":"Mariana Bento, Hannah Cook, Virginia Marin Anaya, Esther Bär, Andrew Nisbet, Ana Lourenço, Mohammad Hussein, Catarina Veiga","doi":"10.1088/2057-1976/ad6f95","DOIUrl":"10.1088/2057-1976/ad6f95","url":null,"abstract":"<p><p><i>Objective.</i>To investigate the potential of 3D-printable thermoplastics as tissue-equivalent materials to be used in multimodal radiotherapy end-to-end quality assurance (QA) devices.<i>Approach.</i>Six thermoplastics were investigated: Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate Glycol (PETG), Polymethyl Methacrylate (PMMA), High Impact Polystyrene (HIPS) and StoneFil. Measurements of mass density (ρ), Relative Electron Density (RED), in a nominal 6 MV photon beam, and Relative Stopping Power (RSP), in a 210 MeV proton pencil-beam, were performed. Average Hounsfield Units (HU) were derived from CTs acquired with two independent scanners. The calibration curves of both scanners were used to predict averageρ,RED and RSP values and compared against the experimental data. Finally, measured data ofρ,RED and RSP was compared against theoretical values estimated for the thermoplastic materials and biological tissues.<i>Main results.</i>Overall, goodρand RSP CT predictions were made; only PMMA and PETG showed differences >5%. The differences between experimental and CT predicted RED values were also <5% for PLA, ABS, PETG and PMMA; for HIPS and StoneFil higher differences were found (6.94% and 9.42/15.34%, respectively). Small HU variations were obtained in the CTs for all materials indicating good uniform density distribution in the samples production. ABS, PLA, PETG and PMMA showed potential equivalency for a variety of soft tissues (adipose tissue, skeletal muscle, brain and lung tissues, differences within 0.19%-8.35% for all properties). StoneFil was the closest substitute to bone, but differences were >10%. Theoretical calculations of all properties agreed with experimental values within 5% difference for most thermoplastics.<i>Significance.</i>Several 3D-printed thermoplastics were promising tissue-equivalent materials to be used in devices for end-to-end multimodal radiotherapy QA and may not require corrections in treatment planning systems' dose calculations. Theoretical calculations showed promise in identifying thermoplastics matching target biological tissues before experiments are performed.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-04DOI: 10.1088/2057-1976/ad773a
Pratap Kumar Koppolu, Krishnan Chemmangat
Hand Movement Recognition (HMR) with sEMG is crucial for artificial
hand prostheses. HMR performance mostly depends on the feature information
that is fed to the classifiers. However, sEMG often captures noise like power line
interference (PLI) and motion artifacts. This may extract redundant and insignificant
feature information, which can degrade HMR performance and increase computational
complexity. This study aims to address these issues by proposing a novel procedure
for automatically removing PLI and motion artifacts from experimental sEMG signals.
This will make it possible to extract better features from the signal and improve
the categorization of various hand movements. Empirical mode decomposition and
energy entropy thresholding are utilized to select relevant mode components for artifact
removal. Time domain features are then used to train classifiers (kNN, LDA, SVM)
for hand movement categorization, achieving average accuracies of 92.36%, 93.63%,
and 98.12%, respectively, across subjects. Additionally, muscle contraction efforts are
classified into low, medium, and high categories using this technique. Validation is
performed on data from ten subjects performing eight hand movement classes and
three muscle contraction efforts with three surface electrode channels. Results indicate
that the proposed preprocessing improves average accuracy by 9.55% with the SVM
classifier, significantly reducing computational time.
{"title":"A novel procedure to automate the removal of PLI and motion artifacts using mode decomposition to enhance pattern recognition of sEMG signals for myoelectric control of prosthesis.","authors":"Pratap Kumar Koppolu, Krishnan Chemmangat","doi":"10.1088/2057-1976/ad773a","DOIUrl":"https://doi.org/10.1088/2057-1976/ad773a","url":null,"abstract":"<p><p>Hand Movement Recognition (HMR) with sEMG is crucial for artificial
hand prostheses. HMR performance mostly depends on the feature information
that is fed to the classifiers. However, sEMG often captures noise like power line
interference (PLI) and motion artifacts. This may extract redundant and insignificant
feature information, which can degrade HMR performance and increase computational
complexity. This study aims to address these issues by proposing a novel procedure
for automatically removing PLI and motion artifacts from experimental sEMG signals.
This will make it possible to extract better features from the signal and improve
the categorization of various hand movements. Empirical mode decomposition and
energy entropy thresholding are utilized to select relevant mode components for artifact
removal. Time domain features are then used to train classifiers (kNN, LDA, SVM)
for hand movement categorization, achieving average accuracies of 92.36%, 93.63%,
and 98.12%, respectively, across subjects. Additionally, muscle contraction efforts are
classified into low, medium, and high categories using this technique. Validation is
performed on data from ten subjects performing eight hand movement classes and
three muscle contraction efforts with three surface electrode channels. Results indicate
that the proposed preprocessing improves average accuracy by 9.55% with the SVM
classifier, significantly reducing computational time.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-04DOI: 10.1088/2057-1976/ad72fa
Yanhua Wu, Hao Wang, Changbo Qu, Xuesong Deng, Na Li, Sile Yue, Wenjing Xu, Yinghua Chen, Ming Zhou
The absence of effective extracellular matrix to mimic the natural tumor microenvironment remains a significant obstacle in cancer research. Matrigel, abundant in various biological matrix components, is limited in its application due to its high cost. This has prompted researchers to explore alternative matrix substitutes. Here, we have investigated the effects of the extracellular matrix derived from pig small intestinal submucosa (ECM-SIS) in xenograft tumor modeling. Our results showed that the pig-derived ECM-SIS effectively promotes the establishment of xenograft tumor models, with a tumor formation rate comparable to that of Matrigel. Furthermore, we showed that the pig-derived ECM-SIS exhibited lower immune rejection and fewer infiltrating macrophages than Matrigel. Gene sequencing analysis demonstrated only a 0.5% difference in genes between pig-derived ECM-SIS and Matrigel during the process of tumor tissue formation. These differentially expressed genes primarily participate in cellular processes, biological regulation, and metabolic processes. These findings emphasize the potential of pig-derived ECM-SIS as a cost-effective option for tumor modeling in cancer research.
{"title":"Pig-derived ECM-SIS provides a novel matrix gel for tumor modeling.","authors":"Yanhua Wu, Hao Wang, Changbo Qu, Xuesong Deng, Na Li, Sile Yue, Wenjing Xu, Yinghua Chen, Ming Zhou","doi":"10.1088/2057-1976/ad72fa","DOIUrl":"10.1088/2057-1976/ad72fa","url":null,"abstract":"<p><p>The absence of effective extracellular matrix to mimic the natural tumor microenvironment remains a significant obstacle in cancer research. Matrigel, abundant in various biological matrix components, is limited in its application due to its high cost. This has prompted researchers to explore alternative matrix substitutes. Here, we have investigated the effects of the extracellular matrix derived from pig small intestinal submucosa (ECM-SIS) in xenograft tumor modeling. Our results showed that the pig-derived ECM-SIS effectively promotes the establishment of xenograft tumor models, with a tumor formation rate comparable to that of Matrigel. Furthermore, we showed that the pig-derived ECM-SIS exhibited lower immune rejection and fewer infiltrating macrophages than Matrigel. Gene sequencing analysis demonstrated only a 0.5% difference in genes between pig-derived ECM-SIS and Matrigel during the process of tumor tissue formation. These differentially expressed genes primarily participate in cellular processes, biological regulation, and metabolic processes. These findings emphasize the potential of pig-derived ECM-SIS as a cost-effective option for tumor modeling in cancer research.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1088/2057-1976/ad6a68
Christiana Subaar, Emmanuel Gyan, Kwadwo A Dompreh, Joseph K Amoako, George Edusei, Alfred Owusu
Magnetic Resonance Imaging (MRI) employs a radiofrequency electromagnetic field to create pictures on a computer. The prospective biological consequences of exposure to radiofrequency electromagnetic fields (RF EMFs) have not yet been demonstrated, and there is not enough evidence on biological hazards to offer a definite response concerning possible RF health dangers. Therefore, it is crucial to research the health concerns in reaction to RF EMFs, considering the entire exposure in terms of patients receiving MRI. Monitoring increases in temperaturein-vivothroughout MRI scan is extremely invasive and has resulted in a rise in the utilization of computational methods to estimate distributions of temperatures. The purpose of this study is to estimate the absorbed power of the brain exposed to RF in patients undergoing brain MRI scan. A three-dimensional Penne's bio-heat equation was modified to computationally analyze the temperature distributions and potential thermal effects within the brain during MRI scans in the 0.3 T to 1.5 T range (12.77 MHz to 63.87 MHz). The instantaneous temperature distributions of thein-vivotissue in the brain temperatures measured at a time, t = 20.62 s is 0.2 °C and t = 30.92 s is 0.4 °C, while the highest temperatures recorded at 1.03 min and 2.06 min were 0.4 °C and 0.6 °C accordingly. From the temperature distributions of thein-vivotissue in the brain temperatures measured, there is heat build-up in patients who are exposed to electromagnetic frequency ranges, and, consequently, temperature increases within patients are difficult to prevent. The study has, however, indicated that lengthier imaging duration appears to be related to increasing body temperature.
{"title":"Numerical simulation in magnetic resonance imaging radiofrequency dosimetry.","authors":"Christiana Subaar, Emmanuel Gyan, Kwadwo A Dompreh, Joseph K Amoako, George Edusei, Alfred Owusu","doi":"10.1088/2057-1976/ad6a68","DOIUrl":"10.1088/2057-1976/ad6a68","url":null,"abstract":"<p><p>Magnetic Resonance Imaging (MRI) employs a radiofrequency electromagnetic field to create pictures on a computer. The prospective biological consequences of exposure to radiofrequency electromagnetic fields (RF EMFs) have not yet been demonstrated, and there is not enough evidence on biological hazards to offer a definite response concerning possible RF health dangers. Therefore, it is crucial to research the health concerns in reaction to RF EMFs, considering the entire exposure in terms of patients receiving MRI. Monitoring increases in temperature<i>in-vivo</i>throughout MRI scan is extremely invasive and has resulted in a rise in the utilization of computational methods to estimate distributions of temperatures. The purpose of this study is to estimate the absorbed power of the brain exposed to RF in patients undergoing brain MRI scan. A three-dimensional Penne's bio-heat equation was modified to computationally analyze the temperature distributions and potential thermal effects within the brain during MRI scans in the 0.3 T to 1.5 T range (12.77 MHz to 63.87 MHz). The instantaneous temperature distributions of the<i>in-vivo</i>tissue in the brain temperatures measured at a time, t = 20.62 s is 0.2 °C and t = 30.92 s is 0.4 °C, while the highest temperatures recorded at 1.03 min and 2.06 min were 0.4 °C and 0.6 °C accordingly. From the temperature distributions of the<i>in-vivo</i>tissue in the brain temperatures measured, there is heat build-up in patients who are exposed to electromagnetic frequency ranges, and, consequently, temperature increases within patients are difficult to prevent. The study has, however, indicated that lengthier imaging duration appears to be related to increasing body temperature.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141878273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1088/2057-1976/ad7265
F Vazquez, A Villareal, J Lazovic, R Martin, S E Solis-Najera, A O Rodriguez
This study introduces a novel volume coil design that features two slotted end-plates connected by six rungs, resembling the traditional birdcage coil. The end rings are equipped with six evenly distributed circular slots, inspired by Mansfield's cavity resonator theory, which suggests that circular slots can generate a baseline resonant frequency. One notable advantage of this proposed coil design is its reduced reliance on electronic components compared to other volume coils, making it more efficient. Additionally, the dimensions of the coil can be theoretically computed in advance, enhancing its practicality. To evaluate the performance and safety of the coil, electromagnetic field and specific absorption rate simulations were simulated using a cylindrical saline phantom and the finite element method. Furthermore, a transceiver coil prototype optimized for 7 Tesla and driven in quadrature was constructed, enabling whole-body imaging of rats. The resonant frequency of the coil prototype obtained through experimental measurements closely matched the theoretical frequency derived from Mansfield's theory. To validate the coil design, phantom images were acquired to demonstrate its viability and assess its performance. These images also served to validate the magnetic field simulations. The experimental results aligned well with the simulation findings, confirming the reliability of the proposed coil design. Importantly, the prototype coil showcased significant improvements over a similarly-sized birdcage coil, indicating its potential for enhanced performance. The noise figure was lower in the prototype versus the birdcage coil (NFbirdcage-NFslotcage= 0.7). Phantom image data were also used to compute the image SNR, giving SNRslotcage/SNRbirdcage= 34.36/24.34. By proving the feasibility of the coil design through successful rat whole-body imaging, the study provides evidence supporting its potential as a viable option for high-field MRI applications on rodents.
{"title":"RF coil that minimizes electronic components while enhancing performance for rodent MRI at 7 Tesla.","authors":"F Vazquez, A Villareal, J Lazovic, R Martin, S E Solis-Najera, A O Rodriguez","doi":"10.1088/2057-1976/ad7265","DOIUrl":"10.1088/2057-1976/ad7265","url":null,"abstract":"<p><p>This study introduces a novel volume coil design that features two slotted end-plates connected by six rungs, resembling the traditional birdcage coil. The end rings are equipped with six evenly distributed circular slots, inspired by Mansfield's cavity resonator theory, which suggests that circular slots can generate a baseline resonant frequency. One notable advantage of this proposed coil design is its reduced reliance on electronic components compared to other volume coils, making it more efficient. Additionally, the dimensions of the coil can be theoretically computed in advance, enhancing its practicality. To evaluate the performance and safety of the coil, electromagnetic field and specific absorption rate simulations were simulated using a cylindrical saline phantom and the finite element method. Furthermore, a transceiver coil prototype optimized for 7 Tesla and driven in quadrature was constructed, enabling whole-body imaging of rats. The resonant frequency of the coil prototype obtained through experimental measurements closely matched the theoretical frequency derived from Mansfield's theory. To validate the coil design, phantom images were acquired to demonstrate its viability and assess its performance. These images also served to validate the magnetic field simulations. The experimental results aligned well with the simulation findings, confirming the reliability of the proposed coil design. Importantly, the prototype coil showcased significant improvements over a similarly-sized birdcage coil, indicating its potential for enhanced performance. The noise figure was lower in the prototype versus the birdcage coil (<i>NF</i><sub>birdcage</sub>-<i>NF</i><sub>slotcage</sub>= 0.7). Phantom image data were also used to compute the image SNR, giving SNR<sub>slotcage</sub>/SNR<sub>birdcage</sub>= 34.36/24.34. By proving the feasibility of the coil design through successful rat whole-body imaging, the study provides evidence supporting its potential as a viable option for high-field MRI applications on rodents.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}