Applied Magnetic Resonance最新文献_第2页

Enhancing Generalization and Mitigating Overfitting in Deep Learning for Brain Cancer Diagnosis from MRI 在MRI脑癌诊断的深度学习中增强泛化和减轻过拟合

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2025-01-03 DOI: 10.1007/s00723-024-01743-y

Mohamad Abou Ali, Jinan Charafeddine, Fadi Dornaika, Ignacio Arganda-Carreras

{"title":"Enhancing Generalization and Mitigating Overfitting in Deep Learning for Brain Cancer Diagnosis from MRI","authors":"Mohamad Abou Ali, Jinan Charafeddine, Fadi Dornaika, Ignacio Arganda-Carreras","doi":"10.1007/s00723-024-01743-y","DOIUrl":"10.1007/s00723-024-01743-y","url":null,"abstract":"<div><p>Brain cancer represents a significant global health challenge with increasing incidence and mortality rates. Magnetic Resonance Imaging (MRI) plays a pivotal role in early detection and treatment planning. This study adopts a systematic approach across four phases: (1) Optimal Model Selection using the Adam optimizer, emphasizing accuracy metrics, weight computation, early stopping, and ReduceLROnPlateau techniques. (2) Real-world Scenario Simulation through synthetic perturbed datasets created by applying noise, blur (to simulate various magnetic field strengths: 1T, 1.5T, 3T), and patient motion artifacts (mimicking MRI scanning motion effects) to the testing data from the BT-MRI dataset, an online published brain tumor MRI dataset. (3) Optimization involving a range of optimizers (Adam, Adagrad, Nadam, RMSprop, SGD) and online augmentation techniques (AutoMix, CutMix, LGCOAMix, PatchUp). (4) Solution Exploration integrating Gaussian Noise and Blur as augmentation strategies during training to enhance model generalization under diverse conditions. Initial evaluations achieved strong performance, consistently reaching 99.45% accuracy on the BT-MRI dataset. However, testing against synthetic perturbed datasets mimicking real-world conditions revealed challenges in maintaining robust model performance. Despite employing diverse optimization methods and advanced augmentation techniques, this study identifies persistent challenges in ensuring model robustness with synthetic perturbed datasets. Notably, the integration of Gaussian Noise and Blur during training significantly improved model resilience. This research underscores the critical role of methodological rigor and innovative augmentation strategies in advancing deep learning applications for precise brain cancer diagnosis using MRI.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 3","pages":"359 - 394"},"PeriodicalIF":1.1,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Robustness and Sensitivity of Gd(III)–Gd(III) Double Electron–Electron Resonance (DEER) Measurements: Comparative Study of High-Frequency EPR Spectrometer Designs and Spin Label Variants Gd(III) -Gd （III）双电子-电子共振（DEER）测量的鲁棒性和灵敏度：高频EPR光谱仪设计和自旋标签变体的比较研究

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2025-01-03 DOI: 10.1007/s00723-024-01741-0

Elena M. Mocanu, Yasmin Ben-Ishay, Lydia Topping, S. Ronan Fisher, Robert I. Hunter, Xun-Cheng Su, Stephen J. Butler, Graham M. Smith, Daniella Goldfarb, Janet E. Lovett

{"title":"Robustness and Sensitivity of Gd(III)–Gd(III) Double Electron–Electron Resonance (DEER) Measurements: Comparative Study of High-Frequency EPR Spectrometer Designs and Spin Label Variants","authors":"Elena M. Mocanu, Yasmin Ben-Ishay, Lydia Topping, S. Ronan Fisher, Robert I. Hunter, Xun-Cheng Su, Stephen J. Butler, Graham M. Smith, Daniella Goldfarb, Janet E. Lovett","doi":"10.1007/s00723-024-01741-0","DOIUrl":"10.1007/s00723-024-01741-0","url":null,"abstract":"<div><p>In this paper, we explore the robustness and sensitivity of Gd(III)-Gd(III) double electron–electron resonance (DEER) distance measurements in proteins for different spectrometer designs and three spin labels. To do this a protein was labeled at the same two positions with Gd(III) spin labels and measurements were performed on two home-built high-frequency (W-band, ~ 95 GHz) EPR spectrometers with different design approaches, and a commercial 150 W Q-band (34 GHz) spectrometer. The first W-band measurement approach uses a conventional, narrow band single mode cavity, while the second uses a broadband non-resonant induction mode sample holder. Both systems incorporate advanced arbitrary waveform generators (AWGs) that give flexibility over excitation bandwidth. We use three DOTA-like Gd(III) spin labels, Gd.C12, Gd.DO3A and Gd.L<sup>1</sup>, conjugated to the calmodulin protein. We compare measurements taken by including or excluding the Gd(III) central transition excitation. The advantages and disadvantages of the EPR spectrometers for the measurement of Gd(III)–Gd(III) DEER are discussed in terms of the robustness of the resulting distance distribution width, absolute and concentration sensitivity, sample handling, ease of use, and flexibility of measurement.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 5","pages":"591 - 611"},"PeriodicalIF":1.1,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-024-01741-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Cylindrical Surface Dielectric Resonator with Substantially High Sensitivity for Deep-Tissue EPR Oximetry 具有高灵敏度的圆柱形表面介电谐振器用于深层组织EPR氧饱和度测定

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-12-31 DOI: 10.1007/s00723-024-01747-8

Sergey V. Petryakov, Maciej M. Kmiec, Ryan C. O’Connell, Conner S. Ubert, Victor B. Kassey, Philip E. Schaner, Periannan Kuppusamy

{"title":"A Cylindrical Surface Dielectric Resonator with Substantially High Sensitivity for Deep-Tissue EPR Oximetry","authors":"Sergey V. Petryakov, Maciej M. Kmiec, Ryan C. O’Connell, Conner S. Ubert, Victor B. Kassey, Philip E. Schaner, Periannan Kuppusamy","doi":"10.1007/s00723-024-01747-8","DOIUrl":"10.1007/s00723-024-01747-8","url":null,"abstract":"<div><p>Electron paramagnetic resonance (EPR) has been established as a unique and reliable method for quantitative in vivo oximetry applicable to a variety of preclinical and clinical studies. A recent clinical study using EPR oximetry with OxyChip from our laboratory demonstrated the feasibility of tumor oxygen measurements in cancer patients (Schaner, et al. Front. Oncol. 2021). During this study, the need to improve oxygen measurement capability in tumors at depths greater than 10 mm became apparent. This prompted us to develop new designs of resonators (RF coils) with enhanced sensitivity for measuring deep-tissue oxygen levels. In this manuscript, we report the development of a new cylindrical surface dielectric resonator (c-SDR) designed with a ceramic dielectric material for substantially enhanced sensitivity and capability for deep-tissue oximetry. The c-SDR was constructed with a cylindrical dielectric material (<i>ϕ</i> 27.2 × 22.2 mm; <i>ε</i> = 160), 6-segmented coupling loop and copper shield to provide an active surface (aperture) of 25 mm with an operating frequency of 1.16 GHz (L-band) and an unloaded <i>Q</i> 600. The resonator could detect OxyChip (<i>ϕ</i> 0.6 × 5 mm) at a surface-to-sample depth of 50 mm in water or 30 mm in a tissue-emulating phantom with a signal-to-noise ratio of 5. Further evaluations of the c-SDR using OxyChip demonstrated its capability for oxygen measurements at depths of 27 mm for 1% oxygen and 15 mm for 5% oxygen in a tissue phantom. In conclusion, the new c-SDR is a significant upgrade to the currently used resonators for in vivo EPR oximetry including clinical oximetry.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 5","pages":"613 - 629"},"PeriodicalIF":1.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Derivation of Multi-Exponential Magnetic Resonance Relaxation Equations in Simple Pore Geometries 简单孔隙几何中多指数磁共振弛豫方程的推导

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-12-24 DOI: 10.1007/s00723-024-01729-w

Armin Afrough

{"title":"Derivation of Multi-Exponential Magnetic Resonance Relaxation Equations in Simple Pore Geometries","authors":"Armin Afrough","doi":"10.1007/s00723-024-01729-w","DOIUrl":"10.1007/s00723-024-01729-w","url":null,"abstract":"<div><p>The common interpretation of magnetic resonance relaxation time distribution of liquids in porous media assumes a one-to-one relationship between the pore size and the relaxation time constants. This common conviction may not be correct in many microporous materials. Each pore size may be associated with more than one peak in the NMR relaxation time distributions: a single dominant peak and also possibly one or a few minor peaks. The appearance of minor peaks is due to the non-vanishing nonground eigenvalues of the diffusion–relaxation equation. Brownstein and Tarr (Phys Rev A 19:2446, 1979) described these features, but their solutions at conditions beyond the fast-diffusion regime are not widely adopted. We provide the derivation of Brownstein–Tarr equations for multi-exponential magnetic resonance relaxation decay for liquids in simple pore geometries. General solutions are presented for planar, cylindrical, and spherical pores—as well as two limiting cases of fast and slow diffusion for each geometry. Similar solutions are also relevant to first-order dilute reactions in porous media in heterogeneous reaction–diffusion systems. We hope that the availability of these derivations helps wider adoption of more realistic interpretation of magnetic resonance relaxation in porous media in the light of the multi-exponential Brownstein–Tarr model.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 3","pages":"313 - 358"},"PeriodicalIF":1.1,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-024-01729-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Preparation of Water-Soluble Tocopherol Compositions Based on N-Vinylpyrrolidone Polymers and Exploration of the Molecular Exchange Process in Aqueous Solutions Using High-Resolution and Pulsed Field Gradient NMR Techniques 基于n -乙烯基吡咯烷酮聚合物的水溶性生育酚组合物的制备及高分辨率和脉冲场梯度核磁共振技术在水溶液中的分子交换过程的探索

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-12-21 DOI: 10.1007/s00723-024-01744-x

Svetlana V. Kurmaz, Ksenia V. Panicheva, Irina A. Avilova, Sergey G. Vasil’ev

{"title":"Preparation of Water-Soluble Tocopherol Compositions Based on N-Vinylpyrrolidone Polymers and Exploration of the Molecular Exchange Process in Aqueous Solutions Using High-Resolution and Pulsed Field Gradient NMR Techniques","authors":"Svetlana V. Kurmaz, Ksenia V. Panicheva, Irina A. Avilova, Sergey G. Vasil’ev","doi":"10.1007/s00723-024-01744-x","DOIUrl":"10.1007/s00723-024-01744-x","url":null,"abstract":"<div><p>Water-soluble compositions of D-<i>α</i>-tocopherol (TP) as an effective antioxidant obtained by its encapsulation into amphiphilic copolymer of <i>N</i>-vinylpyrrolidone with hexyl methacrylate and triethylene glycol dimethacrylate (VP–HMA–TEGDM) and linear polyvinylpyrrolidone (PVP) were studied by electron absorption spectroscopy, dynamic light scattering and by <sup>1</sup>H high-resolution and pulsed field gradient (PFG) NMR. TP absorption band was at 292 nm in the absorption spectra of TP–VP–HMA–TEGDM and TP–PVP solutions, and the TP-loaded nanoparticles in water solution had average hydrodynamic radii, <i>R</i><sub>h</sub>, values about 65 and 57 nm, and diffusion coefficient, <i>D</i><sub>t</sub>, values were 3.7 × 10<sup>–8</sup> and 4.3 × 10<sup>–8</sup> cm<sup>2</sup>/s, respectively. The investigation of the self-diffusion by PFG NMR technique in addition reveals the presence of the phases of small sizes containing TP, which are invisible in DLS measurements. The investigation of the exchange between these phases shows that the retention time of TP in large associates is longer for TP–VP–HMA–TEGDM water solution compared to TP–PVP.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 4","pages":"499 - 519"},"PeriodicalIF":1.1,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-024-01744-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

50 Years of EPR Oximetry: from Capillary to Clinic EPR血氧测定50年：从毛细管到临床

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-12-21 DOI: 10.1007/s00723-024-01745-w

Ryan C. O’Connell, Conner S. Ubert, Maciej M. Kmiec, Sergey V. Petryakov, Victor B. Kassey, Philip E. Schaner, Periannan Kuppusamy

引用次数: 0

Principal Role of EPR Method in Discovery, Identification and Study of Dinitrosyl Iron Complexes in Living Organisms (Review) EPR法在生物体内二硝基铁配合物的发现、鉴定和研究中的主要作用（综述）

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-12-13 DOI: 10.1007/s00723-024-01742-z

Anatoly F. Vanin

引用次数: 0

Two-Pulse Electron Spin Echo of Biradicals: Dependence on Pulse Turning Angles 双基化合物的双脉冲电子自旋回波：与脉冲转角的关系

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-12-12 DOI: 10.1007/s00723-024-01740-1

Victoria N. Syryamina, Olga Yu. Rogozhnikova, Victor M. Tormyshev, Sergei A. Dzuba

引用次数: 0

Using the Time-Domain Nuclear Magnetic Resonance (TD-NMR) for Quantification of the Diesel Adulteration with Ethanol 应用时域核磁共振（TD-NMR）定量分析柴油中乙醇的掺假

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-12-05 DOI: 10.1007/s00723-024-01736-x

Bruno H. Basso, Rodrigo H. S. Garcia, Milton A. Cardoso, Fábio R. Simões, Debora J. Moras, Esther R. D. Lima, Luiz A. Colnago, Lúcio L. Barbosa

{"title":"Using the Time-Domain Nuclear Magnetic Resonance (TD-NMR) for Quantification of the Diesel Adulteration with Ethanol","authors":"Bruno H. Basso, Rodrigo H. S. Garcia, Milton A. Cardoso, Fábio R. Simões, Debora J. Moras, Esther R. D. Lima, Luiz A. Colnago, Lúcio L. Barbosa","doi":"10.1007/s00723-024-01736-x","DOIUrl":"10.1007/s00723-024-01736-x","url":null,"abstract":"<div><p>Diesel is the most important liquid fuel in Brazil, representing 49.6% of the total liquid fuels commercialized in the country and, therefore, is important to have simple and rapid method for diesel quality control. The Brazilian National Agency of Petroleum, Gas and Biofuels verified that 4.0% of the diesel samples did not meet the required specification in 2022. Adulterated fuel increased fuel consumption, cause engine problems, increased emission of polluting gases among others problems. This study presents the use of bench top, time domain nuclear magnetic resonance (TD-NMR) relaxometer as a simple, rapid and non-destructive analytical method to quantify the adulteration of diesel with ethanol, which is the cheapest liquid fuel available in Brazil. The results show that commercial diesel and ethanol have transverse relaxation time (<i>T</i><sub>2</sub>) equal to 0.67 s and 1.75 s, respectively. The addition of 10–90% v/v) ethanol in diesel increased the <i>T</i><sub>2</sub> linearly. The correlation of <i>T</i><sub>2</sub> values with the middle infrared band at 1747 cm<sup>−1</sup> shows determination coefficient (<i>R</i><sup>2</sup> = 0.94). Therefore, TD-NMR relaxometry is a rapid, simple and alternative method to determine the adulteration of the commercial diesel with ethanol.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 4","pages":"441 - 452"},"PeriodicalIF":1.1,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cryogenic W-band Electron Spin Resonance Probehead with an Integral Cryogenic Low Noise Amplifier 带集成低温低噪声放大器的低温w波段电子自旋共振探头

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-12-05 DOI: 10.1007/s00723-024-01732-1

Moamen Jbara, Oleg Zgadzai, Wolfgang Harneit, Aharon Blank

{"title":"Cryogenic W-band Electron Spin Resonance Probehead with an Integral Cryogenic Low Noise Amplifier","authors":"Moamen Jbara, Oleg Zgadzai, Wolfgang Harneit, Aharon Blank","doi":"10.1007/s00723-024-01732-1","DOIUrl":"10.1007/s00723-024-01732-1","url":null,"abstract":"<div><p>The quest to enhance the sensitivity of electron spin resonance (ESR) is an ongoing challenge. One potential strategy involves increasing the frequency, for instance, moving from Q-band (approximately 35 GHz) to W-band (approximately 94 GHz). However, this shift typically results in higher transmission and switching losses, as well as increased noise in signal amplifiers. In this work, we address these shortcomings by employing a W-band probehead integrated with a cryogenic low-noise amplifier (LNA) and a microresonator. This configuration allows us to position the LNA close to the resonator, thereby amplifying the acquired ESR signal with minimal losses. Furthermore, when operated at cryogenic temperatures, the LNA exhibits unparalleled noise levels that are significantly lower than those of conventional room temperature LNAs. We detail the novel probehead design and provide some experimental results at room temperature as well as cryogenic temperatures for representative paramagnetic samples. We find, for example, that spin sensitivity of ~ 3 × 10<sup>5</sup> spins/√Hz is achieved for a sample of phosphorus doped <sup>28</sup>Si, even for sub-optimal sample geometry with potential improvement to < 10<sup>3</sup> spins/√Hz in more optimal scenarios.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 1-2","pages":"265 - 284"},"PeriodicalIF":1.1,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-024-01732-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0