Article
Chemistry, Multidisciplinary
Ke Wu, Xiaoguang Zhao, Thomas G. Bifano, Stephan W. Anderson, Xin Zhang
Summary: Auxetics, with a negative Poisson's ratio, are utilized to design tunable metamaterials for MRI applications, enabling frequency tunability through electromagnetic interaction modification. The metamaterials fabricated using 3D printing technology show an approximate 20 MHz frequency shift during deformation, resulting in a significant boost in MRI signal-to-noise ratio.
ADVANCED MATERIALS
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Sebastian Gassenmaier, Saif Afat, Dominik Nickel, Stephan Kannengiesser, Judith Herrmann, Ruediger Hoffmann, Ahmed E. Othman
Summary: The study showed that applying a novel iterative denoising and image enhancement technique in T1-weighted VIBE imaging of the abdomen can significantly improve image quality, reduce noise levels, and enhance diagnostic confidence without changing the acquisition parameters.
INVESTIGATIVE RADIOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Xia Zhu, Ke Wu, Stephan W. Anderson, Xin Zhang
Summary: Signal-to-noise ratio (SNR) is an important metric for assessing MRI image quality. This study proposes a Helmholtz coil-inspired volumetric wireless resonator that can significantly enhance SNR. Experimental results show that the SNR can be boosted by 5 times or more in the region covering the human knee. This research offers an efficient and practical wireless solution for improving MRI image quality, with potential applications in various imaging fields.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Multidisciplinary
Zhonghai Chi, Yi Yi, Yakui Wang, Maopeng Wu, Lixue Wang, Xihai Zhao, Yonggang Meng, Zhuozhao Zheng, Qian Zhao, Ji Zhou
Summary: An adaptive cylindrical wireless metasurface (ACWM) with homogeneous field enhancement and adaptive resonant modes is reported in this study, which significantly improves the SNR in MRI. The ACWM not only eliminates interference in RF transmitting field, but is also applicable to all common clinical sequences without modifications in scan parameters, offering a practical tool for diagnosing and evaluating human diseases.
ADVANCED MATERIALS
(2021)
Article
Physics, Multidisciplinary
S. T. Chui, Zhifang Lin, Zian Ji
Summary: We demonstrate the concept of resonance in noise through the example of current induced by an external electromagnetic field and noise current in split ring resonators. Both the signal and noise show resonances at the same frequencies, but their ratio varies with frequency and external driving field. This unexpected result suggests that the signal to noise ratio is not solely determined by the resonance frequency, highlighting the need for further research to improve device design.
Article
Radiology, Nuclear Medicine & Medical Imaging
Sebastian Gassenmaier, Judith Herrmann, Dominik Nickel, Stephan Kannengiesser, Saif Afat, Ferdinand Seith, Ruediger Hoffmann, Ahmed E. Othman
Summary: Comparing standard reconstruction with edge enhancement and iterative denoising in DCE imaging of the abdomen, the former showed superior arterial contrast, noise levels, overall image quality, lesion detectability, and diagnostic confidence compared to the latter.
INVESTIGATIVE RADIOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Manuel J. Freire, Jesus Tornero, Ricardo Marques
Summary: This work demonstrates the use of metamaterial lenses to improve the signal-to-noise ratio of magnetic resonance imaging coils in low-field magnetic resonance imaging systems. The dominant source of noise in the signal-to-noise ratio in low-field magnetic resonance imaging systems is the metallization of the coil, while the contribution of noise sample or tissue can be neglected, unlike in high-field magnetic resonance imaging systems. A metamaterial lens composed of a three-dimensional array of capacitively loaded split rings was fabricated and tested on a 0.3 T MRI system. The experiment showed that the metamaterial lens was far enough from the coil to introduce negligible additional losses and tissue losses.
RESULTS IN PHYSICS
(2023)
Article
Neurosciences
Merve Kaptan, S. Johanna Vannesjo, Toralf Mildner, Ulrike Horn, Ronald Hartley-Davies, Valeria Oliva, Jonathan C. W. Brooks, Nikolaus Weiskopf, Juergen Finsterbusch, Falk Eippert
Summary: Functional magnetic resonance imaging (fMRI) of the human spinal cord faces challenges due to signal loss caused by local magnetic field inhomogeneities. This study proposes a slice-specific z-shimming technique to address this issue. The effects of z-shimming on various aspects of spinal fMRI are evaluated, and two automated procedures are developed to improve upon the time-consuming and subjective manual selection of z-shims. The results demonstrate the beneficial effects of z-shimming across different echo times and for both the dorsal and ventral horn. The automated approaches are faster than the manual one, leading to significant improvements in gray matter tSNR compared to no z-shimming. While the field-map-based approach performed slightly worse than the manual one, the EPI-based approach performed as well as the manual one and was validated on an external dataset. Overall, automated z-shimming may enhance data quality and reproducibility in future spinal fMRI studies.
HUMAN BRAIN MAPPING
(2022)
Review
Geochemistry & Geophysics
Thomas Kremer, Trevor Irons, Mike Mueller-Petke, Jakob Juul Larsen
Summary: This paper discusses the application of surface nuclear magnetic resonance (sNMR) method in groundwater monitoring and highlights its limitations. The researchers also propose a series of research methods and future directions to improve the signal-to-noise ratio of this method and expand its application scope.
SURVEYS IN GEOPHYSICS
(2022)
Article
Orthopedics
Jungtae Ahn, Jung Gyu Choi, Bi O. Jeong
Summary: This study found a strong correlation between MRI signal intensities and intraoperative measures of the ATFL, indicating that SNR can predict the arthroscopic reparability of the ATFL.
KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY
(2021)
Article
Acoustics
Emelina P. Vienneau, Kathryn A. Ozgun, Brett C. Byram
Summary: Thermal noise and acoustic clutter degrade ultrasonic image quality and cannot be separately measured in vivo. We derived and validated a method to quantify the individual contributions of thermal noise and acoustic clutter to image degradation by leveraging coherence characteristics.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Kosuke Morita, Hiroyuki Uetani, Takeshi Nakaura, Masami Yoneyama, Yasunori Nagayama, Masafumi Kidoh, Naoki Shinojima, Tadashi Hamasaki, Akitake Mukasa, Toshinori Hirai
Summary: This study aims to evaluate the image quality of the combined technique of compressed sensitivity encoding (CS) and spiral imaging in time-of-flight magnetic resonance angiography (TOF-MRA), which is faster than conventional methods. The results showed that the combined use of CS and spiral imaging improved image quality compared to the individual techniques.
MAGNETIC RESONANCE IMAGING
(2023)
Article
Materials Science, Multidisciplinary
Jegyasu Gupta, Priyanka Das, Ratnajit Bhattacharjee, Debabrata Sikdar
Summary: Magnetic resonance imaging (MRI) is a popular non-invasive diagnostic imaging tool. This study designs a thin and compact metamaterial-based pad that enhances the magnetic field in 1.5T MRI systems, resulting in improved signal-to-noise ratio (SNR) for head MRI scans.
RESULTS IN PHYSICS
(2023)
Article
Engineering, Environmental
Yunlong Luo, Christopher T. Gibson, Clarence Chuah, Youhong Tang, Ravi Naidu, Cheng Fang
Summary: This study successfully visualizes microplastics and nanoplastics released from trimmer lines using Raman imaging, and provides a method for capturing and identifying these plastics with increased signal-noise ratio.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Kritisha Rajlawot, Ting Jiang, Jing Zhou, ChuRong Lin, Sichi Kuang, Jingbiao Chen, Yao Zhang, Hao Yang, Ying Deng, Bingjun He, Diego Hernando, Scott B. Reeder, Jin Wang
Summary: The study compared the diagnostic accuracy of intratumoral fat in HCC using CSE-MRI and IOP imaging sequences, showing that IOP had higher sensitivity while CSE-MRI had higher specificity. The combined use of IOP and CSE-MRI at FA 8 degrees demonstrated the highest AUC and accuracy.
JOURNAL OF MAGNETIC RESONANCE IMAGING
(2021)
Article
Chemistry, Multidisciplinary
Ke Wu, Xiaoguang Zhao, Thomas G. Bifano, Stephan W. Anderson, Xin Zhang
Summary: Auxetics, with a negative Poisson's ratio, are utilized to design tunable metamaterials for MRI applications, enabling frequency tunability through electromagnetic interaction modification. The metamaterials fabricated using 3D printing technology show an approximate 20 MHz frequency shift during deformation, resulting in a significant boost in MRI signal-to-noise ratio.
ADVANCED MATERIALS
(2022)
Article
Optics
Chunxu Chen, Kelson Kaj, Xiaoguang Zhao, Yuwei Huang, Richard Averitt, Xin Zhang
Summary: Metasurfaces have shown great potential in controlling electromagnetic waves using arrays of subwavelength resonators. In this study, a mechanically reconfigurable metasurface based on a microelectromechanical system (MEMS) is presented for dynamic surface wave switching at terahertz frequencies. The metasurface allows for efficient conversion between plane waves and surface waves with a wide working bandwidth. This technology has applications in spatial light modulation, beam steering, focusing, and beam combining for future communication systems.
Article
Engineering, Electrical & Electronic
Ryan McNaughton, Yuda Huo, Guicai Li, Anais Di Via Ioschpe, Lei Yan, Heng-Ye Man, Xin Zhang
Summary: This study demonstrates the use of microfabrication techniques to monitor the morphological and synaptic connectivity changes of neurons in response to physical stimuli. The results show that microtopography can enhance neuron adhesion and axon growth, while inhibiting dendritic arborization and presynaptic puncta architecture.
JOURNAL OF MICROMECHANICS AND MICROENGINEERING
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Ryan McNaughton, Chris Pieper, Osamu Sakai, Julie Rollins, Xin Zhang, David N. Kennedy, Jean A. Frazier, Laurie Douglass, Timothy Heeren, Rebecca C. Fry, T. Michael O'Shea, Karl K. Kuban, Hernan Jara
Summary: This study compared the differences in brain structural parameters between adolescents born extremely preterm with autism spectrum disorder, cerebral palsy, epilepsy, or cognitive impairment and typically developing adolescents. The study found that sex played an important role in brain development, with lower white matter proton density in girls with atypical development and longer white matter T1 in boys with atypical development, which were associated with microstructural organization in white matter.
Article
Nanoscience & Nanotechnology
Yuwei Huang, Kelson Kaj, Chunxu Chen, Zhiwei Yang, Sheikh Rubaiat Ul Haque, Yuan Zhang, Xiaoguang Zhao, Richard D. Averitt, Xin Zhang
Summary: This article introduces a thin membrane silicon metasurface absorber that achieves very high absorption over a bandwidth of approximately 500 GHz. The absorber can be used in terahertz devices such as detectors, modulators, and switches.
Article
Nanoscience & Nanotechnology
Ke Wu, Guangwu Duan, Xiaoguang Zhao, Chunxu Chen, Stephan William Anderson, Xin Zhang
Summary: RFID technology is widely used in industrial applications for tracking and tracing products, assets, and material flows. The trend towards miniaturized RFID sensor tags continues to advance, but presents challenges for communication coverage area. Recent efforts have focused on using metamaterials to increase power transfer efficiency in RFID systems. Applying magnetic metamaterials and local field enhancement package to near-field RFID technology offers high power transfer efficiency and larger communication coverage area, creating new opportunities in the emerging Internet of Things era.
MICROSYSTEMS & NANOENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Samuel H. Kann, Erin M. Shaughnessey, Jonathan R. Coppeta, Hesham Azizgolshani, Brett C. Isenberg, Else M. Vedula, Xin Zhang, Joseph L. Charest
Summary: This study integrates optical-based oxygen sensors in a high-throughput organ-on-chip platform to monitor the metabolic activity of cells in membrane bilayer devices. By measuring oxygen changes in real-time and estimating cell oxygen consumption rates using a finite element analysis model, metabolic shifts in human renal proximal tubule cells following exposure to different drugs were successfully detected.
MICROSYSTEMS & NANOENGINEERING
(2022)
Article
Physics, Applied
Ao Chen, Xiaoguang Zhao, Zhiwei Yang, Stephan Anderson, Xin Zhang
Summary: Ventilated acoustic insulation, based on labyrinthine metamaterials, is a promising research direction in applied acoustics. The proposed design shows potential for high-performance wide-band acoustic insulation and ventilation. The design achieves effective soundproofing in the frequency range and provides a foundation for the development of broadband ventilated acoustic insulators.
PHYSICAL REVIEW APPLIED
(2022)
Article
Materials Science, Multidisciplinary
Yuwei Huang, Kelson Kaj, Chunxu Chen, Zhiwei Yang, Richard D. Averitt, Xin Zhang
Summary: Bound states in the continuum (BIC) is an exotic concept describing systems without radiative loss. This study introduces a structurally tunable BIC terahertz metamaterial fabricated using micromachining and characterized using terahertz time domain spectroscopy. The bending angle of the metamaterial is controlled by thermal actuation to modify the capacitance and achieve tuning from a quasi-BIC state to the BIC state. Temporal coupled mode theory (CMT) is used to gain additional insight into the tunable electromagnetic response of the metamaterial.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Physics, Applied
Ao Chen, Zhiwei Yang, Xiaoguang Zhao, Stephan Anderson, Xin Zhang
Summary: We propose a composite acoustic metamaterial consisting of Mie resonators and a Helmholtz resonator array, which achieves a broadband acoustic attenuation in the low-frequency regime. The wideband soundproofing effect is explained using the transfer-matrix method and the lumped-element model, and the transmission loss and transmittance are tested numerically and experimentally. By using a deep-subwavelength structure, our composite design successfully blocks over 90% of incident acoustic energy within a frequency range of 1250 Hz, offering a design paradigm for extraordinary airborne acoustic silencing in low-frequency regimes.
PHYSICAL REVIEW APPLIED
(2023)
Article
Materials Science, Multidisciplinary
Xia Zhu, Ke Wu, Stephan W. Anderson, Xin Zhang
Summary: Signal-to-noise ratio (SNR) is an important metric for assessing MRI image quality. This study proposes a Helmholtz coil-inspired volumetric wireless resonator that can significantly enhance SNR. Experimental results show that the SNR can be boosted by 5 times or more in the region covering the human knee. This research offers an efficient and practical wireless solution for improving MRI image quality, with potential applications in various imaging fields.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Analytical
Samuel H. Kann, Erin M. Shaughnessey, Xin Zhang, Joseph L. Charest, Else M. Vedula
Summary: Monitoring steady state oxygen levels in a high-throughput organ-on-chip platform with integrated optical-based oxygen sensors can evaluate drug-induced nephrotoxicity in a human microfluidic co-culture model of the kidney proximal tubule. The study demonstrates the dose and time-dependent injury responses of human PT cells to cisplatin using oxygen consumption measurements in the platform. The results highlight the utility of steady state oxygen measurements as a rapid, non-invasive, and kinetic readout of drug-induced injury in high-throughput microfluidic kidney co-culture models.
