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The increasing signal‐to‐noise ratio (SNR) is the main reason to use ultrahigh field MRI. Here, we investigate the dependence of the SNR on the magnetic field strength, especially for small animal applications, where small surface coils are used and coil noise cannot be ignored. Measurements were performed at five field strengths from 3 to 14.1 T, using 2.2‐cm surface coils with an identical coil design for transmit and receive on two water samples with and without salt. SNR was measured in a series of spoiled gradient echo images with varying flip angle and corrected for saturation based on a series of flip angle and T1 measurements. Furthermore, the noise figure of the receive chain was determined and eliminated to remove instrument dependence. Finally, the coil sensitivity was determined based on the principle of reciprocity to obtain a measure for ultimate SNR. Before coil sensitivity correction, the SNR increase in nonconductive samples is highly supralinear with B01.6–2.7, depending on distance to the coil, while in the conductive sample, the growth is smaller, being around linear close to the surface coil and increasing up to a B02.0 dependence when moving away from the coil. After sensitivity correction, the SNR increase is independent of loading with B02.1. This study confirms the supralinear increase of SNR with increasing field strengths. Compared with most human measurements with larger coil sizes, smaller surface coils, as mainly used in animal studies, have a higher contribution of coil noise and thus a different behavior of SNR at high fields. [ABSTRACT FROM AUTHOR]

This narrative review explores recent advancements and applications of modern low-field (≤ 1 Tesla) magnetic resonance imaging (MRI) in musculoskeletal radiology. Historically, high-field MRI systems (1.5 T and 3 T) have been the standard in clinical practice due to superior image resolution and signal-to-noise ratio. However, recent technological advancements in low-field MRI offer promising avenues for musculoskeletal imaging. General principles of low-field MRI systems are being introduced, highlighting their strengths and limitations compared to high-field counterparts. Emphasis is placed on advancements in hardware design, including novel magnet configurations, gradient systems, and radiofrequency coils, which have improved image quality and reduced susceptibility artifacts particularly in musculoskeletal imaging. Different clinical applications of modern low-field MRI in musculoskeletal radiology are being discussed. The diagnostic performance of low-field MRI in diagnosing various musculoskeletal pathologies, such as ligament and tendon injuries, osteoarthritis, and cartilage lesions, is being presented. Moreover, the discussion encompasses the cost-effectiveness and accessibility of low-field MRI systems, making them viable options for imaging centers with limited resources or specific patient populations. From a scientific standpoint, the amount of available data regarding musculoskeletal imaging at low-field strengths is limited and often several decades old. This review will give an insight to the existing literature and summarize our own experiences with a modern low-field MRI system over the last 3 years. In conclusion, the narrative review highlights the potential clinical utility, challenges, and future directions of modern low-field MRI, offering valuable insights for radiologists and healthcare professionals seeking to leverage these advancements in their practice. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to investigate the dependence of Intravoxel Incoherent Motion (IVIM) parameters measured in the human calf on B0. Methods: Diffusion-weighted image data of eight healthy volunteers were acquired using five b-values (0–600 s/mm2) at rest and after muscle activation at 0.55 and 7 T. The musculus gastrocnemius mediale (GM, activated) was assessed. The perfusion fraction f and diffusion coefficient D were determined using segmented fits. The dependence on field strength was assessed using Student’s t-test for paired samples and the Wilcoxon signed-rank test. A biophysical model built on the three non-exchanging compartments of muscle, venous blood, and arterial blood was used to interpret the data using literature relaxation times. Results: The measured perfusion fraction of the GM was significantly lower at 7 T, both for the baseline measurement and after muscle activation. For 0.55 and 7 T, the mean f values were 7.59% and 3.63% at rest, and 14.03% and 6.92% after activation, respectively. The biophysical model estimations for the mean proton-density-weighted perfusion fraction were 3.37% and 6.50% for the non-activated and activated states, respectively. Conclusions: B0 may have a significant effect on the measured IVIM parameters. The blood relaxation times suggest that 7 T IVIM may be arterial-weighted whereas 0.55 T IVIM may exhibit an approximately equal weighting of arterial and venous blood.

Aim Ohmic heating (OH) (i.e. heating by electric field) more effectively kills bacterial spores than traditional wet heating, yet its mechanism remains poorly understood. This study investigates the accelerated spore inactivation mechanism using genetically modified spores. Methods and results We investigated the effects of OH and conventional heating (CH) on various genetically modified strains of Bacillus subtilis : isogenic PS533 (wild type_1), PS578 [lacking spores' α/β-type small acid-soluble proteins (SASP)], PS2318 (lacking recA , encoding a DNA repair protein), isogenic PS4461 (wild type_2), and PS4462 (having the 2Duf protein in spores, which increases spore wet heat resistance and decreases spore inner membrane fluidity). Removal of SASP brought the inactivation profiles of OH and CH closer, suggesting the interaction of these proteins with the field. However, the reemergence of a difference between CH and OH killing for SASP-deficient spores at the highest tested field strength suggested there is also interaction of the field with another spore core component. Additionally, RecA-deficient spores yielded results like those with the wild-type spores for CH, while the OH resistance of this mutant increased at the lower tested temperatures, implying that RecA or DNA are a possible additional target for the electric field. Addition of the 2Duf protein markedly increased spore resistance both to CH and OH, although some acceleration of killing was observed with OH at 50 V/cm. Conclusions In summary, both membrane fluidity and interaction of the spore core proteins with electric field are key factors in enhanced spore killing with electric field-heat combinations. [ABSTRACT FROM AUTHOR]

Radiation shielding plays a crucial role in safeguarding human health, and ongoing research is exploring alternative materials for this vital purpose. Herein, physical and radiation-shielding features of the manufactured glasses via melt-quenching technique doped with ZrO2 within a glassy system, (100-x-y)[SrTiO3]-x[2B2O3·SiO2]-y(ZrO2), (39 ≤ x ≤ 40, and 0 ≤ y ≤ 4 mol % ZrO2) were studied. The density (ρ) and field-strength (Fs) values of the synthesized glasses were found to be in an increasing order of 2.6068–3.0720 g/cm3 and 5.2401–14.2399 Å−2 respectively. The study also encompassed an exploration of the radiation shielding properties such as mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half value length, tenth value length, mean free path, effective atomic number (Zeff), and effective electron-density (Neff) of the synthesized glasses, employing the freely available 'Phy-X/PSD' software within the energy range of 0.015–15 MeV. The highest values of MAC, LAC, and Neff at 0.02 MeV were found to be 25.275 cm2/g, 77.644 cm−1, and 8.42 × 1023 electrons/g for SrTZ4 (x = 39 and y = 4) glass respectively. Notably, among all the fabricated glasses, SrTZ4 emerged as the standout performer, demonstrating superior gamma-radiation protecting abilities along with effective physical properties. Thus, the fabricated SrTZ4 glass with its remarkable radiation shielding properties holds promising applications for the development of radiation protection equipment. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to investigate the dependence of Intravoxel Incoherent Motion (IVIM) parameters measured in the human calf on B0. Methods: Diffusion-weighted image data of eight healthy volunteers were acquired using five b-values (0–600 s/mm2) at rest and after muscle activation at 0.55 and 7 T. The musculus gastrocnemius mediale (GM, activated) was assessed. The perfusion fraction f and diffusion coefficient D were determined using segmented fits. The dependence on field strength was assessed using Student's t-test for paired samples and the Wilcoxon signed-rank test. A biophysical model built on the three non-exchanging compartments of muscle, venous blood, and arterial blood was used to interpret the data using literature relaxation times. Results: The measured perfusion fraction of the GM was significantly lower at 7 T, both for the baseline measurement and after muscle activation. For 0.55 and 7 T, the mean f values were 7.59% and 3.63% at rest, and 14.03% and 6.92% after activation, respectively. The biophysical model estimations for the mean proton-density-weighted perfusion fraction were 3.37% and 6.50% for the non-activated and activated states, respectively. Conclusions: B0 may have a significant effect on the measured IVIM parameters. The blood relaxation times suggest that 7 T IVIM may be arterial-weighted whereas 0.55 T IVIM may exhibit an approximately equal weighting of arterial and venous blood. [ABSTRACT FROM AUTHOR]

The field strength effect on fracture toughness was tested for three alkaline earth (AE) aluminoborosilicate (ABS) glasses. This work explores the impact of modifier field strength (FS) on macro‐mechanical properties in line with previous works which examined the FS effect on structure, hardness, crack resistance, and elastoplastic properties of alkali and AE‐ABS glasses. Fracture toughness (KIcVNB) was found to increase as modifier FS increased; and the elastoplastic ratio (HV/E) correlated well with plasticity, hardness, and fracture toughness. The purpose of this work is to examine the mechanical response of AE‐ABS glasses at a larger length scale in order to determine whether the field strength effect is active as was observed at lower length scales in previous works. The observed increase and decrease of the KIcVNB and HV/E, respectively, with increasing modifier FS, suggest a strong correlation between increasing fracture toughness and crack resistance with increasing plasticity for the AE‐ABS glasses studied. [ABSTRACT FROM AUTHOR]

Modern standards of digital terrestrial broadcasting allow for more efficient use of the frequency resource, they provide multimedia, scalability and flexibility of the network, support for wireless receivers, local channels, and different time modes of content delivery. Digitalization of the existing network reduces energy consumption by times by television transmitters, positively affecting the environment, which corresponds to the current trends of reducing the carbon footprint including the consequences of the introduction of modern radio broadcasting technologies. The purpose of the present work is to calculate the signals of the radio relay station of a digital terrestrial television broadcasting network for the modernization of the network in the Naryn region of the Kyrgyz Republic. The method of predicting the propagation of radio waves based on statistical analysis and experimental data, and methods of determining electromagnetic compatibility in the design of digital terrestrial television broadcasting networks are used for calculations. Calculations of the service area of digital television transmitters; calculation of energy indices of useful and interfering signals, minimum median field strength of radio relay station Ala-Myshyk, efficiency of radiated power, interpolation of field strength as a function of distance for the lower and upper frequencies are made. Recommendations on the application of the method of propagation prediction in determining the full-service area of digital television transmitters considering the terrain are given. The technical and economic indicators are calculated: the number of equipment for the stations of the modernized network is determined, the total cost of acquisition, transportation and installation of new equipment, and the annual consumption of electricity consumed by digital television transmitters is calculated. The result and methodology of calculations were applied to other stations of the network in Naryn oblast of Kyrgyzstan for its modernization and they can be used for cases of modernization of the broadcasting network in mountainous areas. [ABSTRACT FROM AUTHOR]

Introduction: Brain age, the estimation of a person's age from magnetic resonance imaging (MRI) parameters, has been used as a general indicator of health. The marker requires however further validation for application in clinical contexts. Here, we show how brain age predictions perform for the same individual at various time points and validate our findings with age‐matched healthy controls. Methods: We used densely sampled T1‐weighted MRI data from four individuals (from two densely sampled datasets) to observe how brain age corresponds to age and is influenced by acquisition and quality parameters. For validation, we used two cross‐sectional datasets. Brain age was predicted by a pretrained deep learning model. Results: We found small within‐subject correlations between age and brain age. We also found evidence for the influence of field strength on brain age which replicated in the cross‐sectional validation data and inconclusive effects of scan quality. Conclusion: The absence of maturation effects for the age range in the presented sample, brain age model bias (including training age distribution and field strength), and model error are potential reasons for small relationships between age and brain age in densely sampled longitudinal data. Clinical applications of brain age models should consider of the possibility of apparent biases caused by variation in the data acquisition process. [ABSTRACT FROM AUTHOR]

Some target refrigerants used in refrigeration systems have various flammability. Once the flammable refrigerants leak into a confined space, it is easy to pose safety hazards. Moreover, the leakage refrigerants undergo continuous expansion and compression processes in the near field of the confined space, and the field strength of the refrigerants changes dramatically, which has an impact on the diffusion and the concentration distribution of the refrigerant in the far field of the confined space. The differences in the field strength and the flammable area for different refrigerants are largely determined by the thermophysical parameters of the refrigerants. Therefore, to better assess the hazards of refrigerant leakage, R717, R290, R161, R32, R152a and R1234yf were selected as the targeted leakage refrigerants in this paper, R744 and R134a were selected as the referenced refrigerants, the temperature, velocity and concentration fields of the refrigerants leaking into a confined space were studied, the influence of thermophysical parameters on the field strength of the refrigerants in the near field was further analyzed, and the flammable area formed in the space was explored. The results found that the temperature field was mainly affected by the density and the specific heat of the refrigerant. The velocity field was mainly affected by the density and viscosity of the refrigerant. The concentration field was mainly influenced by the density, viscosity and diffusion coefficient of the refrigerant. When the density was close, Schmidt number could be used to assess the influence of the viscosity and the diffusion coefficient on the concentration field. Under the same leakage pressure, the range of the flammable area formed by the leakage of R290 was the largest, followed by R161 and R152a, the flammable areas of R1234yf and R717 were very close, and the flammable area formed by R32 was the smallest. [ABSTRACT FROM AUTHOR]

The field strength (FS) effect of six different network modifiers on the elastoplastic properties of aluminoborosilicate glasses was explored using a volumetric recovery study. This work, in conjunction with Part I, explored the intersection of hardness, crack resistance, and other physical properties with glass elasticity. Results showed that (1) the elastic volume fraction decreased with FS for both the alkali and alkaline earth (AE) glasses; (2) the Poisson's ratio did not trend with pile‐up or shear flow volume fraction; (3) the elastic‐to‐plastic deformation ratio increased with applied load and decreased with modifier FS for both the alkali and AE glasses; and (4) an increase in plasticity correlated with increased hardness, crack resistance, and elastic moduli. [ABSTRACT FROM AUTHOR]

The modifier field strength (FS) is believed to play an important role in determining the elastic–plastic responses of aluminoborosilicate (ABS) glasses, but its effect is not well understood. Three novel alkali and three alkaline earth (AE) ABS compositions were created for this study which is the first part of two studies that explored the elastoplastic responses of these glasses. Six compositions were designed using different network modifiers (NWMs) to cover a range of cation FS. The glasses were also designed such that the concentrations of NWM and Al2O3 were similar, which maximized the three‐coordinated boron fraction in the network. It is well known that modifier FS can affect the coordination number (CN) of Al and B in an ABS glass structure, for example, a higher FS modifier can promote B3 → B4 and higher [Al5,6], but the degree of this depends on network former (NWF) ratios. Previous work used solid‐state NMR spectroscopic analysis on the current glasses to find that there was variation between [B4] and [Al4] between the two glass series (alkali vs. AE) but that was attributed to synthesis factors and no trend with FS was associated with the varying NWF CN. Further, 29Si ssNMR showed no evidence of NBOs which made sense based on composition. The conclusion, therefore, was that there was a far greater correlation with modifier FS for the increased mechanical and physical properties rather than the CN of Al and B. Part I of the current work focused on the elastic moduli, Poisson's ratio, the indentation size effect (ISE), and the bow‐in parameter. This part laid out the foundation to investigate the intersection of these elastoplastic properties with hardness and crack resistance as a function of NWM FS. Results showed that: (i) the Young's, bulk, and shear moduli increased with modifier FS, whereas Poisson's ratio did not trend with FS; (ii) the alkali glasses had a significantly higher magnitudes of ISE compared to the AE glasses; and (iii) the bow‐in parameter was load dependent and decreased with modifier FS at the highest indentation load. [ABSTRACT FROM AUTHOR]

The article describes the development of cell engineering technologies that use various electroporation modes and require knowledge of the electrical characteristics of living cells. Usually, cells are taken from laboratory animals of the same species, and the question of specific features of electrical characteristics of living cells remains open. Using the method of pulsed conductometry in an electric field of increasing strength, the electrical characteristics (conductivity, strength) were measured during electroporation and electrical breakdown of oocytes membranes of the following mammalian species: Mus musculus (mouse), Oryctolagus cuniculus (rabbit), Sus scrofa (pig), Bos taurus (cow), and Homo sapiens (human). Mathematical analysis of the experimental dependences of the conductivity of mammalian oocytes based on polynomial approximation was performed. The electrical characteristics of oocytes were obtained based on the analysis of approximating polynomials for the presence of maximum curvature (membrane electrical breakdown) and inflection points and local extrema (the degree of reversible electroporation). Significant species differences in the measured electrical characteristics of the studied oocytes were established. The measurement results showed a significant species specificity of electrical characteristics, reflecting the different resistance of oocytes to electrical breakdown and the degree of reversible electroporation of membranes, which is probably associated with the peculiarities of the lipid composition of oocyte membranes, the integrity of the cytoskeleton structure, and the resistance of cells as a whole to the impact of a pulsed field. The results obtained can be used to implement various modes of electromanipulation with a living cell, i.e., electrotransfection of deoxyribonucleic acid (DNA), genes, electrofusion, as well as for point lysis of cells with a lost apoptosis mechanism. [ABSTRACT FROM AUTHOR]

Recently published studies have revealed a correlation between MRI-based vertebral bone quality (VBQ) score and bone mineral density (BMD) measured using dual X-ray absorptiometry (DXA) or quantitative computed tomography (QCT). However, no studies have determined if differences in field strength (1.5 vs 3.0 T) could affect the comparability of the VBQ score among different individuals. To compare the VBQ score obtained from 1.5 T and 3.0 T MRI (VBQ 1.5T vs VBQ 3.0T) in patients undergoing spine surgery and assess the predictive performance of VBQ for osteoporosis and osteoporotic vertebral fracture (VCF). A nested case‒control study based on an ongoing prospective cohort study of patients undergoing spine surgery. All older patients (men aged >60 years and postmenopausal women) with available DXA, QCT and MR images within 1 month were included. VBQ score, DXA T-score, and QCT derived vBMD. The osteoporotic classifications recommended by the World Health Organization and American College of Radiology were used to categorize the DXA T-score and QCT-derived BMD, respectively. For each patient, the VBQ score was calculated using T1-weighted MR images. Correlation analysis between VBQ and DXA/QCT was performed. Receiver operating characteristic (ROC) curve analysis, including determination of the area under the curve (AUC), was performed to assess the predictive performance of VBQ for osteoporosis. A total of 452 patients (98 men aged >60 years and 354 postmenopausal women) were included in the analysis. Across different BMD categories, the correlation coefficients between the VBQ score and BMD ranged from -0.211 to -0.511, and the VBQ 1.5T score and QCT BMD demonstrated the strongest correlation. The VBQ score was a significant classifier of osteoporosis detected by either DXA or QCT, with VBQ 1.5T showing the highest discriminative power for QCT-osteoporosis (AUC=0.744, 95% CI=0.685–0.803). In ROC analysis, the VBQ 1.5T threshold values ranged from 3.705 to 3.835 with a sensitivity between 48% and 55.6% and a specificity between 70.8% and 74.8%, while the VBQ 3.0T threshold values ranged from 2.59 to 2.605 with a sensitivity between 57.6% and 67.1% and a specificity between 67.8% and 69.7%. VBQ 1.5T exhibited better discriminability between patients with and without osteoporosis than VBQ 3.0T. Considering the non-negligible difference in osteoporosis diagnosis threshold values between the VBQ 1.5T and VBQ 3.0T scores, it is essential to clearly distinguish the magnetic field strength when assessing the VBQ score. [ABSTRACT FROM AUTHOR]

Abstract Introduction Brain age, the estimation of a person's age from magnetic resonance imaging (MRI) parameters, has been used as a general indicator of health. The marker requires however further validation for application in clinical contexts. Here, we show how brain age predictions perform for the same individual at various time points and validate our findings with age‐matched healthy controls. Methods We used densely sampled T1‐weighted MRI data from four individuals (from two densely sampled datasets) to observe how brain age corresponds to age and is influenced by acquisition and quality parameters. For validation, we used two cross‐sectional datasets. Brain age was predicted by a pretrained deep learning model. Results We found small within‐subject correlations between age and brain age. We also found evidence for the influence of field strength on brain age which replicated in the cross‐sectional validation data and inconclusive effects of scan quality. Conclusion The absence of maturation effects for the age range in the presented sample, brain age model bias (including training age distribution and field strength), and model error are potential reasons for small relationships between age and brain age in densely sampled longitudinal data. Clinical applications of brain age models should consider of the possibility of apparent biases caused by variation in the data acquisition process.

BACKGROUND: Diffusion-weighted imaging (DWI) is the random Brownian motion of water molecules within a tissue voxel. The apparent diffusion coefficient (ADC) is a quantitative parameter calculated from the DWI that directly reflects the mobility of water molecules in biological tissues. The objective of this study was to establish and compare the normal reference ADC values of fetal organs and the placenta using 1.5 T and 3.0 T MRI at various gestational ages. METHODS: This was a retrospective and prospective observational study. This study included one hundred and three (103) singleton pregnancies for each magnetic field strength. Diffusion-weighted imaging was performed using single-shot spin-echo-planar imaging (EPI) in the axial plane of the fetal head-trunk with a slice thickness of 4mm and diffusion gradient values of b = 0 and b = 700-800 s/mm². RESULTS: The mean ADC values of cerebral WM areas were significantly higher than the deep grey areas in the brain. The white-matter regions, lung, and placenta showed a positive and significant correlation with increasing gestational age in both field strengths. A statistically weak negative correlation was observed between increasing gestational age and ADC measurements obtained in the thalamus, cerebellum, pons, and kidney. CONCLUSION: This study gives the reference values for both 1.5T and 3T MRI of vital organs. The current study shows that diffusion-weighted MRI can offer a promising technique to evaluate the structural development of fetal organs and can potentially act as a biomarker for predicting the functionality of the fetal organs in abnormalities. [ABSTRACT FROM AUTHOR]

Object: Lower-field MR is reemerging as a viable, potentially cost-effective alternative to high-field MR, thanks to advances in hardware, sequence design, and reconstruction over the past decades. Evaluation of lower field strengths, however, is limited by the availability of lower-field systems on the market and their considerable procurement costs. In this work, we demonstrate a low-cost, temporary alternative to purchasing a dedicated lower-field MR system. Materials and Methods: By ramping down an existing clinical 3 T MRI system to 0.75 T, proton signals can be acquired using repurposed 13C transmit/receive hardware and the multi-nuclei spectrometer interface. We describe the ramp-down procedure and necessary software and hardware changes to the system. Results: Apart from presenting system characterization results, we show in vivo examples of cardiac cine imaging, abdominal two- and three-point Dixon-type water/fat separation, water/fat-separated MR Fingerprinting, and point-resolved spectroscopy. In addition, the ramp-down approach allows unique comparisons of, e.g., gradient fidelity of the same MR system operated at different field strengths using the same receive chain, gradient coils, and amplifiers. Discussion: Ramping down an existing MR system may be seen as a viable alternative for lower-field MR research in groups that already own multi-nuclei hardware and can also serve as a testing platform for custom-made multi-nuclei transmit/receive coils. [ABSTRACT FROM AUTHOR]

The electromagnetic reverberation chamber (reverberation chamber, RC) finds the corresponding reference value of the level value and the field strength under different working conditions, explores the field strength uniformity in the effective working area, and finally identifies the area where the field strength is relatively stable in the effective working areato provide a reference for the study of electromagnetic radiation biological effects and protection. At the three frequencies of 900 MHz, 1 800 MHz and 2 650 MHz, the electromagnetic radiation detector was used to monitor 324 field strength test points in the effective working area of RC, and the R language and related statistical software were used for analysis. The result shows that when the fixed frequency is 900 MHz and the level value is - 25 dBm, there is no statistical difference in the field strength and coefficient of variation of the three heights in the effective working area. When the fixed frequency is 1 800 MHz and the level value is - 21 dBm, the field strength is statistically significant between heights 1 and 3, height 2 and height 3, and the coefficient of variation has no statistical difference between the three heights. When the fixed frequency is 2 650 MHz and the level value is - 19 dBm, the field strength is statistically significant between height 1 and height 2, height 1 and height 3, and the coefficient of variation has no statistical difference between the three heights. It can be seen that the field strength corresponding to the corresponding level value at the three frequencies of 900 MHz, 1 800 MHz and 2 650 MHz is provided, which provides a reference for the development of related experiments; the field strength at a single point in the effective working area of the RC has good stability with time, while the field strength at different points has a certain spatial instability. The area where the field strength is relatively stable in the effective working area is the height-one area. [ABSTRACT FROM AUTHOR]

Background: Left ventricular (LV) strain measurements can be derived using cardiac MRI from routinely acquired balanced steady‐state free precession (bSSFP) cine images. Purpose: To compare the interfield strength agreement of global systolic strain, peak strain rates and artificial intelligence (AI) landmark‐based global longitudinal shortening at 1.5 T and 3 T. Study Type: Prospective. Subjects: A total of 22 healthy individuals (mean age 36 ± 12 years; 45% male) completed two cardiac MRI scans at 1.5 T and 3 T in a randomized order within 30 minutes. Field Strength/Sequence: bSSFP cine images at 1.5 T and 3 T. Assessment: Two software packages, Tissue Tracking (cvi42, Circle Cardiovascular Imaging) and QStrain (Medis Suite, Medis Medical Imaging Systems), were used to derive LV global systolic strain in the longitudinal, circumferential and radial directions and peak (systolic, early diastolic, and late diastolic) strain rates. Global longitudinal shortening and mitral annular plane systolic excursion (MAPSE) were measured using an AI deep neural network model. Statistical Tests: Comparisons between field strengths were performed using Wilcoxon signed‐rank test (P value < 0.05 considered statistically significant). Agreement was determined using intraclass correlation coefficients (ICCs) and Bland–Altman plots. Results: Minimal bias was seen in all strain and strain rate measurements between field strengths. Using Tissue Tracking, strain and strain rate values derived from long‐axis images showed poor to fair agreement (ICC range 0.39–0.71), whereas global longitudinal shortening and MAPSE showed good agreement (ICC = 0.81 and 0.80, respectively). Measures derived from short‐axis images showed good to excellent agreement (ICC range 0.78–0.91). Similar results for the agreement of strain and strain rate measurements were observed with QStrain. Conclusion: The interfield strength agreement of short‐axis derived LV strain and strain rate measurements at 1.5 T and 3 T was better than those derived from long‐axis images; however, the agreement of global longitudinal shortening and MAPSE was good. Evidence Level: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Although the interactions among glass formers and modifiers, for example, connectivity and charge distribution, have been studied extensively in oxide glasses, the impact of a particular modifier species on the mechanical performance of aluminoborosilicate (ABS) glasses is not well understood. This work compares the indentation properties of six ABS glasses, each of which contains a different network modifier (NWM) with varying field strength (FS). Three alkali and three alkaline earth ABS glasses were designed with low NWM content and [NWM] ≈ [Al2O3], to test the modifier FS effect at low concentrations and to maximize three‐coordinated boron. It has been found that both hardness and crack resistance increase with increasing FS in these ABS systems, which is surprising in the context of historical reports. Using 11B, 27Al, and 29Si solid‐state nuclear magnetic resonance, this work provides evidence of how charge distributions differ as a function of NWM species, and how this relates to the observed indentation behaviors. [ABSTRACT FROM AUTHOR]

This paper reports the alkali field strength effect on structural, optical, dielectric, and conducting properties of calcium borosilicate glasses. Glass compositions 60SiO 2 –5B 2 O 3 –15CaO-20R 2 O (where R = Li, Na, K) are synthesized by melt-quench technique. The density shows an increasing trend with the increasing atomic weight of substituted alkali metal oxides. On the other hand, the hardness and elastic modulus are found to decrease from Li 2 O to K 2 O. The tendency of oxide ions to donate electrons is found to increase with decreasing field strength of alkali ions in the glass. The optical band gap of glasses is found in the insulating range, i.e. 4.27 eV–4.38 eV. The diffusion coefficient and conductivity of Li 2 O-containing glass is the highest followed by Na 2 O and K 2 O. Present synthesized glasses are found to be suitable for use as a substrate in thin film solar cells. [ABSTRACT FROM AUTHOR]

Most current traffic safety evaluations using traffic conflict techniques are based on the principles of vehicle dynamics and kinematics. In these evaluations, a lack of consideration of the coupling mechanism among drivers, road users and the road environment leads to a large limitation in the practical application of such evaluations. In this paper, we firstly considered the driver characteristics in traffic conflicts and introduced the electric field model to establish the psychological field model of a driver in a conflict environment and to obtain the psychological field strength of the driver. Secondly, based on the classification criteria of traffic conflict severity, the psychological field strengths of drivers in different traffic conflict scenarios were categorized, and the range values of psychological field strengths of different severity levels were obtained. Finally, the analysis of the experimental results showed that the mean value and standard deviation of the drivers' mental field strengths were the largest in the opposite-direction conflict, indicating the largest dispersion of the field strengths; in the construction conflict, the mean value and standard deviation of the drivers' mental field strengths were the smallest, indicating the smallest dispersion of the field strengths. [ABSTRACT FROM AUTHOR]

At present, in typical architectures of feedforward neural networks, the values of the weights of the connections and thresholds of neurons are determined by adjusting the values of the weights, performed by means of typical learning algorithms. The architectures of feedforward neural networks implemented on the basis of metric recognition methods are also known, the values of the weights of neurons for which are precalculated analytically. The analytical calculation of the weight values is carried out on the basis of metric expressions and allows a workable neural network to be immediately obtained without training. In this case, the effectiveness of the obtained neural network depends on the selected set and the number of samples, as well as on the selected dimension of the table of weights. Such neural networks can also be trained with typical learning algorithms, which makes it possible to increase the efficiency of the neural network with the calculated weights through additional training of the neural network. Here, the process of calculating the weight values and the further training of the neural network is also faster than training the neural network in the traditional way; on the basis of these networks, the possibility of determining the weight values and thresholds of a neural network using the strength and potential of the electrostatic field is considered. That is, it is proposed to use the parameter values of the electrostatic field as weight values of a neural network. In other words, the possibility of creating a workable neural network without analytical calculations and without the use of learning algorithms is considered. This approach allows the process of determining the values of the neural network weights almost instantaneous. The technically possible implementations of this approach and the problematic aspects of using the parameters of the electrostatic field as weights of a neural network, as well as possible approaches to resolving these difficulties are considered. [ABSTRACT FROM AUTHOR]

The main element of the reference field-forming system of the State Primary Standard of the unit of electric field strength in the frequency range from 0 to 20 kHz under GET 158-2020 is a reference converter consisting of a shielded capacitor with flat round plates and additional electrodes connected to an AC or DC voltage source. Due to the approval of the standard in the specified composition and the change in the power supply scheme of the reference field-forming system from asymmetric to symmetric, the maximum value of the intensity reproduced by the standard has been increased from 2000 to 4000 V/m and the accuracy of its reproduction and transmission has been increased. For the case of a symmetric power supply, it was necessary to derive a measurement equation linking the reproducible value and the input parameters of the reference converter (voltage, geometric dimensions). The derivation of the measurement equation of a reference converter excited by a symmetric voltage is presented, obtained as a result of solving an electrostatic problem with symmetric boundary conditions for the potential of the electrodes. Optimal values of the voltages applied to the additional electrodes are found in order to obtain maximum uniformity of the electric field in the region of the center of the converter. It is shown that the nonuniformity of the field for a specific implementation of a shielded capacitor is no greater than 0.1%. The results obtained can be used in the field of the metrology of constant and variable electric fields in the development of reference sources of electric field and working standards. [ABSTRACT FROM AUTHOR]

Bioactive borosilicate glasses are the most preferred and well-known glasses for orthopedic applications due to their excellent properties. However, some negative aspects of borosilicate glasses like low optical, structural, and electrical features restricted their use. Thus, to enhance the mentioned drawbacks, Ag2O with different ratios of x = 0, 2, 4, 6, 8, and 10 wt.% are added to the borosilicate glasses. The obtained results show that the Polaron radius (rp), Inter-nuclear distance (ri), and Field Strength will increase up to 4.8181 Å, 11.9570 Å, and 2.0246 × 1016 cm− 2. The transmittance, absorbance, and absorbance coefficient (α) are highly improved from BS-Ag0 to BS-Ag10. Furthermore, the values of constraint number (NS) and cross-linking density (CD) show that the chosen samples' rigidity increase from 11.080 to 11.090 and 9.080 to 9.090. In addition, at the low energy region sudden peaks are recorded in Ceff curves for BS-Ag2, BS-Ag4, BS-Ag6, BS-Ag8, and BS-Ag10 at E = 25.51 KeV which is related to the K-edge absorption of the Ag element. From the obtained results it can be concluded that Ag2O is responsible for the enhancement of the radiation shielding, structural, optical, and electrical features of the bioactive borosilicate glasses. [ABSTRACT FROM AUTHOR]

Purpose: The SNR at the center of a spherical phantom of known electrical properties was measured in quasi‐identical experimental conditions as a function of magnetic field strength between 3 T and 11.7 T. Methods: The SNR was measured at the center of a spherical water saline phantom with a gradient‐recalled echo sequence. Measurements were performed at NeuroSpin at 3, 7, and 11.7 T. The phantom was then shipped to Maastricht University and then to the University of Minnesota for additional data points at 7, 9.4, and 10.5 T. Experiments were carried out with the exact same type of birdcage volume coil (except at 3 T, where a similar coil was used) to attempt at isolating the evolution of SNR with field strength alone. Phantom electrical properties were characterized over the corresponding frequency range. Results: Electrical properties were found to barely vary over the frequency range. Removing the influence of the flip‐angle excitation inhomogeneity was crucial, as expected. After such correction, measurements revealed a gain of SNR growing as B01.94 ± 0.16 compared with B02.13 according to ultimate intrinsic SNR theory. Conclusions: By using quasi‐identical experimental setups (RF volume coil, phantom, electrical properties, and protocol), this work reports experimental data between 3 T and 11.7 T, enabling the comparison with SNR theories in which conductivity and permittivity can be assumed to be constant with respect to field strength. According to ultimate SNR theory, these results can be reasonably extrapolated to the performance of receive arrays with greater than about 32 elements for central SNR in the same spherical phantom. [ABSTRACT FROM AUTHOR]

The study explored the effects of electric field strength, temperature, and frequency on the inactivation of Clostridium sporogenes PA3679 spores (a surrogate of Clostridium botulinum) within buffer. The experiments were conducted at three different field strengths (30, 40, and 50 V/cm), temperatures (110, 120, and 130 °C), and frequencies (60, 1000, and 5000 Hz). Ohmic heating resulted in significantly greater reduction of C. sporogenes compared to conventional heating. Electric field strength significantly influenced spore inactivation. It was found that lower frequencies led to quicker rates of inactivation. Given that high field strengths have dual benefits of increasing both heating and spore kill rate, the possibility exists to process foods to sterility without a hold. This is expected to result in improved product quality, reduced process times and increased efficiency. • Ohmic heating results in higher bacterial spore inactivation than conventional heating. • This study also confirms the existence of non-thermal effects of ohmic heating. • Higher field strength offered significantly higher inactivation of spores. • 60Hz and 5000 Hz offered highest and lowest inactivation of Clostridium sporogenes. [ABSTRACT FROM AUTHOR]

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Single photocatalysts usually exhibit unsatisfactory performance due to the serious recombination of photogenerated electron‒hole pairs. Combining two photocatalysts to construct S-scheme heterojunction could solve this problem. In S-scheme mechanism, the interfacial built-in electric field (IEF) provides a vital driving force for efficient charge separation. Modifying the IEF is a feasible strategy to further improve the photocatalytic activity. Herein, a novel idea of tuning the strength of IEF in 2D/2D graphitic carbon nitride (g-C3N4)/MS2 (M = Sn, Zr) S-scheme heterojunctions by nonmetal doping was developed by employing density functional theory calculation. Three nonmetal elements (O, P, and S) were severally introduced into g-C3N4/MS2 composites. Charge density difference suggested that O and S doping led to increased interfacial electron transfer, while P doping had minimal influence. As expected, the calculated field strength of O- and S-doped g-C3N4/MS2 composites was significantly larger than that of pristine and P-doped g-C3N4/MS2 composites. Therefore, O and S doping endowed g-C3N4/MS2 S-scheme heterojunctions with enhanced IEF and more thorough charge transfer. Correspondingly, the experimentally synthesized O-C3N4/SnS2 composite exhibited better photocatalytic H2-production activity than g-C3N4/SnS2 composite. This work proposed an original idea of employing proper nonmetal doping to magnify the advantage of S-scheme heterojunction in accelerating charge separation.

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Copyright of Der Radiologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Penelitian ini bertujuan untuk menganalisis pengaruh adanya tower seluler terhadap kualitas penerimaan siaran TV di daerah padat penduduk yang berada di Jalan Buring Dalam Kecamatan Klojen, Kota Malang. Dari hasil pengukuran nilai kuat medan secara Line of Sight dan With Obstacle akan diketahui nilai redaman yang terjadi akibat adanya obstacle dengan jenis seluler. Setelah dilakukan pengukuran, akan dibandingkan dengan hasil perhitungan. Hasil penelitian ini adalah analisa pengaruh dari obstacle dengan jenis tower seluler terhadap pensinyalan tv analog, dengan membandingkan hasil pengukuran dan perhitungan yang didapat dari perhitungan kuat medan yang diterima menggunakan perhitungan redaman berdasarkan Rekomendasi ITU-R P.1546-1 dengan metode Okumura Hata, dan teori difraksi knife edge. Kesimpulan, hasil pengukuran dengan adanya obstacle tower seluler diperoleh rata – rata selisih antara Line of Sight dan With Obstacle sebesar 2.6525 dB dengan jarak obstacle 15 m dari titik pengukuran, dan 4.548571 dB dengan jarak 40 m . Nilai estimasi redaman rata – rata yang dipengaruhi difraksi tower seluler dengan jarak obstacle 15 m dari titik pengukuran sebesar 41.1088 dB, dan dengan jarak 40 m sebesar 36.67143 dB.Nilai redaman tower seluler berdasarkan pengukuran untuk jarak 15 m dari obstacle didapatkan nilai sebesar 2.6525 dB dan untuk perhitungan sebesar 41.1088 dB Sedangkan nilai redaman tower seluler berdasarkan hasil pengukuran untuk jarak 40 m memiliki rata – rata sebesar 4.548571 dB dan untuk perhitungan sebesar 36.67143 dB.

The calculation apparatus acceptable for assumptions and simplifications and sufficient for errors of final results for modeling the propagation of electric, magnetic and electromagnetic fields spread over a certain area was proposed. It is shown that to model the propagation of ultra-low frequency electric and magnetic fields (monitors, uninterruptible power supplies, transformers, electric motors and generators) it is possible to consider these sources as dipole and dipole-quadrupole type sources. That is, the field of the local source can be considered as a combination of electric and magnetic dipoles. This makes it possible to delineate with sufficient accuracy the zones of exceeding the maximum allowable field strengths. The calculation apparatus used to determine the radiation intensities of civil aviation radar equipment was adapted to model the propagation of electromagnetic fields of very high and ultra-high frequencies. The calculations of coefficients that take into account the parameters of radiation patterns in the horizontal and vertical planes for the most common radiation sources are given. These ratios and corresponding coefficients can be used to determine the electromagnetic environment in the presence of many high-frequency sources (mobile communication base stations, navigation equipment, radio relay stations, etc.). The proposed approach allows to automate processes of designing the placement of electromagnetic, electronic and radio equipment in production areas and territories, as well as to assess the environmental impact at the stages of design work. This will make it possible to delineate the isolines of the limits of exceeding the maximum permissible levels of electric magnetic and electromagnetic fields for different frequency ranges and categories of equipment and to automatically determine the electromagnetic load at each point of the controlled space.

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: In-vivo diffusion tensor cardiovascular magnetic resonance (DT-CMR) is an emerging technique for microstructural tissue characterization in the myocardium. Most studies are performed at 3T, where higher signal-to-noise ratio (SNR) should benefit this signal-starved method. However, a few studies have suggested that DT-CMR is possible at 1.5T, where echo planar imaging artifacts may be less severe and 1.5T hardware is more widely available., Methods: We recruited 20 healthy volunteers and performed mid-ventricular short-axis DT-CMR at 1.5T and 3T. Acquisitions were performed at peak systole and end-diastole using both stimulated echo acquisition mode (STEAM) and motion-compensated spin-echo (MCSE) sequences at matched spatial resolutions. DT-CMR parameters were averaged over the left ventricle and compared between 1.5T and 3T sequences using both datasets with and without the b low reference data included., Results: Eleven (1.5T) and 12 (3T) diastolic MCSE acquisitions were rejected as the helix angle (HA) demonstrated <50% normal appearance circumferentially or the acquisition was abandoned due to poor image quality; a maximum of one acquisition was rejected for other datasets. Subjective HA map quality was significantly better at 3T than 1.5T for STEAM (p < 0.05), but not for MCSE and other DT-CMR quality measures were consistent with improvements in STEAM at 3T over 1.5T. When b low data were excluded, no significant differences in mean diffusivity were observed between field strengths, but fractional anisotropy was significantly higher at 1.5T than 3T for STEAM systole (p < 0.05). Absolute second eigenvector orientation (E2A, sheetlet angle) was significantly higher at 1.5T than 3T for MCSE systole and STEAM diastole, but significantly lower for STEAM systole (all p < 0.05). Transmural HA distribution was less steep at 1.5T than 3T for STEAM diastole data (p < 0.05). SNR was higher at 3T than 1.5T for all acquisitions (p < 0.05)., Conclusion: While 3T provides benefits in terms of SNR, both STEAM and MCSE can be performed at 1.5T. However, MCSE is unreliable in diastole at both field strengths and STEAM benefits from the improved SNR at 3T over 1.5T. Future clinical research studies may be able to leverage the wider availability of 1.5T CMR hardware where MCSE acquisitions are desirable., Competing Interests: Declaration of competing interests The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The Cardiovascular Magnetic Resonance Unit at the Royal Brompton Hospital receives research support from Siemens. Ke Wen and Yaqing Luo are partly funded by Siemens., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to investigate the dependence of Intravoxel Incoherent Motion (IVIM) parameters measured in the human calf on B 0 . Methods: Diffusion-weighted image data of eight healthy volunteers were acquired using five b -values (0-600 s/mm 2 ) at rest and after muscle activation at 0.55 and 7 T. The musculus gastrocnemius mediale (GM, activated) was assessed. The perfusion fraction f and diffusion coefficient D were determined using segmented fits. The dependence on field strength was assessed using Student's t -test for paired samples and the Wilcoxon signed-rank test. A biophysical model built on the three non-exchanging compartments of muscle, venous blood, and arterial blood was used to interpret the data using literature relaxation times. Results: The measured perfusion fraction of the GM was significantly lower at 7 T, both for the baseline measurement and after muscle activation. For 0.55 and 7 T, the mean f values were 7.59% and 3.63% at rest, and 14.03% and 6.92% after activation, respectively. The biophysical model estimations for the mean proton-density-weighted perfusion fraction were 3.37% and 6.50% for the non-activated and activated states, respectively. Conclusions: B 0 may have a significant effect on the measured IVIM parameters. The blood relaxation times suggest that 7 T IVIM may be arterial-weighted whereas 0.55 T IVIM may exhibit an approximately equal weighting of arterial and venous blood.

Radiomic features extracted from breast lesion images have shown potential in diagnosis and prognosis of breast cancer. As medical centers transition from 1.5 T to 3.0 T magnetic resonance (MR) imaging, it is beneficial to identify potentially robust radiomic features across field strengths because images acquired at different field strengths could be used in machine learning models. Dynamic contrast-enhanced MR images of benign breast lesions and hormone receptor positive/HER2-negative (HR+/HER2-) breast cancers were acquired retrospectively, yielding 612 unique cases: 150 and 99 benign lesions imaged at 1.5 T and 3.0 T, and 223 and 140 HR+/HER2- cancerous lesions imaged at 1.5 T and 3.0 T, respectively. In addition, an independent set of seven lesions imaged at both field strengths, three benign lesions and four HR+/HER2- cancers, was analyzed separately. Lesions were automatically segmented using a 4D fuzzy c-means method; thirty-eight radiomic features were extracted. Feature value distributions were compared by cancer status and imaging field strength using the Kolmogorov-Smirnov test. Features that did not demonstrate a statistically significant difference were considered to be potentially robust. The area under the receiver operating characteristic curve (AUC), for the task of classifying lesions as benign or HR+/HER2- cancer, was determined for each feature at each field strength. Three features were found to be both potentially robust across field strength and of high classification performance, i.e., AUCs statistically greater than 0.5 in the classification task: one shape feature (irregularity), one texture feature (sum average) and one enhancement variance kinetics features (enhancement variance increasing rate). In the demonstration set of lesions imaged at both field strengths, two of the three potentially robust features showed qualitative agreement across field strength. These findings may contribute to the development of computer-aided diagnosis models that are robust across field strength for this classification task. [ABSTRACT FROM AUTHOR]

This study considers the potential distribution in the ground when a railroad overhead wire falls onto the ground. It is shown that, in the case of direct current, the distribution of the potential and voltage at a growing distance from the source is sharply uneven and the nature of the unevenness changes over time. The high temperature at the point at which the wire falls, leads to the ground near this zone exhibiting minimal specific resistance; this causes further preferential heating of the near-contact area. In the case of direct current at a high temperature coefficient of resistance and a positive ambient temperature, the latter has almost no influence on the values of the potential and the current density. Negative ambient temperatures result in high electrical-potential values. In the near-contact region, however, the potential changes in a smoother manner, which leads to lower field strengths and current densities in this region. With growing distance from the contact point, the most dangerous temperature range is from −2 to 0°C, a range that leads to high electric-field strength and potential values. At an alternating voltage, the temperature distribution deep into the ground from the point where the wire has fallen is extremely uneven, and this unevenness increases even more over time. An increase in the moisture content in the ground causes a sharp increase in the field strength and current density in the near-contact region. However, in areas far from the wire-fall point, these values are slightly higher in a dry environment than in a wet one. [ABSTRACT FROM AUTHOR]

Abstract. The paper presents the data on the energy intensity of the heat treatment of grain during post-harvest processing caused by both the cost of energy and the grain moisture content. The development of processing modes using electrical technologies, in general, and electromagnetic fields, in particular, can make it possible to reduce the cost of these processes. Heat treatment is applied to the grain of various crops at the stages of drying, disinfection, preparation for feeding, etc. When developing them, it is necessary to take into account the types of applied electrical technologies, such as, for example, infrared fields, microwave fields, etc. (Research purpose) To determine the dielectric properties (dielectric loss coefficient) of a wheat grain-air mixture with a moisture content of 11-30 percents with a layer density of 220-660 kilogram per cubic meter. (Materials and methods) The authors present a diagram of a laboratory installation, carried out experimental studies to determine the dielectric loss coefficient of a fluidized bed of wheat grain. (Results and discussion) The authors conducted a two-factor experiment to determine the effect of moisture and density of a grain bulk on the dielectric loss factor, which determines the power absorbed from the microwave source. As a result, they obtained the studied relationships. (Conclusions) It was found that the dielectric loss coefficient at a grain moisture content of 11-30 percents is in the range of 0.18-0.42 for a dense grain bed of 660 kilogram per cubic meter, 0.06-0.15 for a fluidized bed (440 kilogram per cubic meter); and for a weighted bed (220 kilogram per cubic meter) 0.1-0.3. The authors calculated a dependence of the dielectric loss coefficient of a wheat grain-and-air layer on the grain moisture content and the layer density, which can be described by a polynomial model of a second power. The study showed that fluidization of the grain bed increases the efficiency of the microwave field, as due to a decrease in the dielectric loss coefficient, the depth of field penetration into the layer increases. It is recommended to use the microwave field in a dense bed of grain when drying wheat, thus reducing moisture from 16 to 14 percent.

A streaming television usually broadcasted through internet and can be watched on computer or mobile phone. However it can also be seen through television using video sender as the transmitter. To transmit it, of course, a suitable antenna is needed, in this case a bowtie antenna is selected. This research describe the design of a bowtie antenna that will be used as a transmitter antenna on a video sender. This bowtie antenna is designed by using an aluminum plate works on frequency of 655 MHz and has a return loss value of -21.127 dB, VSWR 1.192, 5.11 dB gain and bi-directional radiation pattern. The analysis process is carried out by analyzing the data taken from the audio and video results received in television as well as data from the measurement of signal strength captured by Register Transfer Level Software Define Radio (RTL SDR) and dipole antennas. Measurement results will be displayed in the sdrSharp software. The results of this measurement will be associated with field strength which is related to television signals. This bowtie antenna can transmit audio and video up to 30 m and has an average field strength value in Line of Sight (LOS) conditions of 120.3208 dBμV / m and at Non Line of Sight (NLOS) conditions of 123.5014 dBμV / m which is in accordance with the field strength standard in Indonesia that regulated in Perkominfo No. 31 Tahun 2014 which is above 70 dBμV / m in band V.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective surgical treatment for Parkinson’s disease (PD). Side-effects may, however, be induced when the DBS lead is placed suboptimally. Currently, lower field magnetic resonance imaging (MRI) at 1.5 or 3 Tesla (T) is used for targeting. Ultra-high-field MRI (7 T and above) can obtain superior anatomical information and might therefore be better suited for targeting. This study aims to test whether optimized 7 T imaging protocols result in less variable targeting of the STN for DBS compared to clinically utilized 3 T images. Three DBS-experienced neurosurgeons determined the optimal STN DBS target site on three repetitions of 3 T-T2, 7 T-T2*, 7 T-R2* and 7 T-QSM images for five PD patients. The distance in millimetres between the three repetitive coordinates was used as an index of targeting variability and was compared between field strength, MRI contrast and repetition with a Bayesian ANOVA. Further, the target coordinates were registered to MNI space, and anatomical coordinates were compared between field strength, MRI contrast and repetition using a Bayesian ANOVA. The results indicate that the neurosurgeons are stable in selecting the DBS target site across MRI field strength, MRI contrast and repetitions. The analysis of the coordinates in MNI space however revealed that the actual selected location of the electrode is seemingly more ventral when using the 3 T scan compared to the 7 T scans.