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Implementation of a novel 288-element dual-frequency array for acoustic angiography: in vitro & in vivo characterization.

IEEE Trans Ultrason Ferroelectr Freq Control 2021 Apr 19;PP. Epub 2021 Apr 19.

Acoustic angiography is a superharmonic contrast-enhanced ultrasound imaging method that produces high-resolution, three-dimensional maps of the microvasculature. Previous acoustic angiography studies have used two-element, annular, mechanically actuated transducers (called "wobblers") to image microvasculature in preclinical tumor models with high contrast-to-tissue ratio and resolution, but these early wobbler transducers could not achieve the depth and sensitivity required for clinical acoustic angiography. In this work, we present a system for performing acoustic angiography with a novel dual-frequency transducer - a coaxially stacked dual-frequency array. Read More

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Model-based reconstruction algorithm in the detection of acute trauma-related lesions in brain CT examinations.

Neuroradiol J 2021 Apr 19:19714009211008751. Epub 2021 Apr 19.

School of Medicine, University of Milano-Bicocca, Italy.

Background And Purpose: To evaluate the added value of a model-based reconstruction algorithm in the assessment of acute traumatic brain lesions in emergency non-enhanced computed tomography, in comparison with a standard hybrid iterative reconstruction approach.

Materials And Methods: We retrospectively evaluated a total of 350 patients who underwent a 256-row non-enhanced computed tomography scan at the emergency department for brain trauma. Images were reconstructed both with hybrid and model-based iterative algorithm. Read More

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Development of NO-MTV for low-speed flow and in-situ deployment to an integral effect test facility.

Exp Fluids 2017 Dec;59

Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, DC, USA.

A molecular tagging velocity (MTV) technique is developed to non-intrusively measure velocity in an integral effect test (IET) facility simulating a high temperature helium-cooled nuclear reactor in accident scenarios. In these scenarios, the velocities are expected to be low, on the order of 1 m/s or less, which forces special requirements on the MTV tracer selection. Nitrous oxide (NO) is identified as a suitable seed gas to generate NO tracers capable of probing the flow over a large range of pressure, temperature, and flow velocity. Read More

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December 2017

Determining the thermomechanical image shift for the MIGHTI instrument on the NASA-ICON satellite.

Opt Eng 2020 Jan 11;59(1). Epub 2020 Jan 11.

St. Cloud State University, Department of Physics, St. Cloud, Minnesota, United States.

The Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI) instrument on NASA's Ionospheric Connection Explorer's mission will measure neutral winds in the Earth's thermosphere. We investigate how thermal changes to the instrument's optical bench affect the relative position of the image recorded by the camera. The thermal shift is measured by fitting the image of a series of reference notches and determining their current position on the camera with subpixel precision. Read More

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January 2020

Changes in Magnetic Resonance Imaging Using the Prostate Cancer Radiologic Estimation of Change in Sequential Evaluation Criteria to Detect Prostate Cancer Progression for Men on Active Surveillance.

Eur Urol Oncol 2021 Apr 21;4(2):227-234. Epub 2020 Oct 21.

Urologic Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA. Electronic address:

Background: The ability of serial magnetic resonance imaging (MRI) to capture pathologic progression during active surveillance (AS) remains in question.

Objective: To determine whether changes in MRI are associated with pathologic progression for patients on AS.

Design, Setting, And Participants: From July 2007 through January 2020, we identified all patients evaluated for AS at our institution. Read More

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A Novel Chemiluminescence Probe for Sensitive Detection of Fibroblast Activation Protein-Alpha In Vitro and in Living Systems.

Anal Chem 2021 Apr 18. Epub 2021 Apr 18.

Shanghai Key Laboratory of Bioactive Small Molecules & Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University, Shanghai 201203, P. R. China.

Fibroblast activation protein-alpha (FAPα) is a key modulator of the microenvironment in multiple pathologies and is becoming the next pan-cancer target for cancer diagnostics and therapeutics. Chemiluminescence (CL) luminophores are considered as one of the most sensitive families of probes for detection and imaging applications due to their high signal-to-noise ratio. Until now, however, no such effective CL probe was reported for FAPα detection. Read More

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Risk Stratification With the Use of Coronary Computed Tomographic Angiography in Patients With Nonobstructive Coronary Artery Disease.

JACC Cardiovasc Imaging 2021 Apr 8. Epub 2021 Apr 8.

Cardiovascular Imaging Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.

Objectives: The purpose of this study was to develop a risk prediction model for patients with nonobstructive CAD.

Background: Among stable chest pain patients, most cardiovascular (CV) events occur in those with nonobstructive coronary artery disease (CAD). Thus, developing tailored risk prediction approaches in this group of patients, including CV risk factors and CAD characteristics, is needed. Read More

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Total-body F-FDG PET/CT scan in oncology patients: how fast could it be?

Eur J Nucl Med Mol Imaging 2021 Apr 18. Epub 2021 Apr 18.

Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.

Purpose: The aim of the study was to determine a faster PET acquisition protocol for a total-body PET/CT scanner by assessing the image quality that is equivalent to a conventional digital PET/CT scanner from both a phantom and a clinical perspective.

Methods: A phantom study using a NEMA/IEC NU-2 body phantom was first performed in both a total-body PET/CT (uEXPLORER) and a routine digital PET/CT (uMI 780), with a hot sphere to background activity concentration ratio of 4:1. The contrast recovery coefficient (CRC), background variability (BV), and recovery coefficient (RC: RC and RC) were assessed in the uEXPLORER with different scanning durations and reconstruction protocols, which were compared to those acquired from the uMI 780 with clinical acquisition settings. Read More

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Prediction of Coronary Stent Underexpansion by Pre-Procedural Intravascular Ultrasound-Based Deep Learning.

JACC Cardiovasc Interv 2021 Apr 7. Epub 2021 Apr 7.

Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

Objectives: The aim of this study was to develop pre-procedural intravascular ultrasound (IVUS)-based models for predicting the occurrence of stent underexpansion.

Background: Although post-stenting IVUS has been used to optimize percutaneous coronary intervention, there are no pre-procedural guidelines to estimate the degree of stent expansion and provide preemptive management before stent deployment.

Methods: A total of 618 coronary lesions in 618 patients undergoing percutaneous coronary intervention were randomized into training and test sets in a 5:1 ratio. Read More

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Scalable Single-Crystalline Organic 1D Arrays for Image Sensor.

Small 2021 Apr 17:e2100332. Epub 2021 Apr 17.

Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.

Optoelectronic applications of organic semiconductors demand single-crystalline structures with long-range order and suppressed defects for sustaining efficient carrier transport and long photocarrier lifetime, which are pivotal in photodetection, photovoltaic, and light emission. For integrated devices, an additional requirement of precise patterning is imposed, whereas the patterning of single-crystalline organic microstructures is still challenging because the molecular stacking is easily perturbed by disordered fluids in microdroplets. Herein, a capillary-bridge lithography is developed for driving the directional transport of capillary flows to control the confined crystallization of organic 1D single-crystalline arrays with aligned positioning and pure orientation. Read More

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Incidence and factor analysis of laryngohyoid fractures in hanging individuals-computed tomography study.

Eur Radiol 2021 Apr 16. Epub 2021 Apr 16.

Department of Diagnostic Radiology, Graduate School of Biomedical and Health Science, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan.

Objectives: Although laryngohyoid fracture indicates the applied neck pressure and is an important finding in hanging individuals, the reported rate varies widely and its true incidence remains controversial. We used computed tomography (CT) studies to investigate the incidence of laryngohyoid fracture in hanging individuals and identify factors contributing to such fractures.

Methods: Considered for inclusion in this study were 107 attempted or successful hanging individuals subjected to CT studies between 2005 and 2019. Read More

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Does Tc-tilmanocept, as next generation radiotracer, meet with the requirements for improved sentinel node imaging?

Rev Esp Med Nucl Imagen Mol 2021 Apr 13. Epub 2021 Apr 13.

Sección de Medicina Nuclear & Laboratorio de Imagen Molecular Intervencionista, Departamento de Radiología, Centro Médico Universidad de Leiden, Leiden, Países Bajos; Departamento de Radiología y Medicina Nuclear, Hospital Onze Lieve Vrouwe Gasthuis, Ámsterdam, Países Bajos.

Introduction And Objectives: To evaluate the migration of Tc-tilmanocept from the injection site (IS) as well as the uptake in sentinel nodes (SNs) and non-SNs for lymphatic mapping in patients with breast cancer and melanoma, scheduled for SN biopsy after interstitial tracer administration.

Materials And Methods: For 29 primary tumours in 28 patients (mean age: 62y, range: 45-81y) scheduled for SN biopsy planar images were acquired 10 and 120 min after administration of 74 MBq Tc-tilmanocept, in order to evaluate lymphatic drainage as well as uptake ratios between injection site (IS), SN and non-SN. SPECT/CT was performed immediately after delayed planar images to enable anatomical lymph node localization. Read More

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Safety of image-guided radiotherapy in definitive radiotherapy for localized prostate cancer: a population-based analysis.

Br J Radiol 2021 Apr 16:20200456. Epub 2021 Apr 16.

Department of Radiation Oncology, China Medical University Hospital, Taichung, Taiwan.

Objectives: Image-guided radiotherapy (IGRT) is a recommended advanced radiation technique that is associated with fewer acute and chronic toxicities. However, one Phase III trial showed worse overall survival in the IGRT arm. The purpose of this observational study is to evaluate the impact of IGRT on overall survival. Read More

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Preoperative prediction of pathologic grade of HCC on gadobenate dimeglumine-enhanced dynamic MRI.

Eur Radiol 2021 Apr 16. Epub 2021 Apr 16.

Department of Radiology and Guangdong Key Laboratory of Liver Disease, Third Affiliated Hospital of Sun Yat-sen University, No. 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China.

Purpose: To evaluate the value of gadobenate dimeglumine-enhanced MRI in predicting the pathologic grade of hepatocellular carcinoma (HCC).

Materials And Methods: Patients with pathologically proven HCC who underwent preoperative gadobenate dimeglumine-enhanced dynamic MRI were included. Two radiologists blinded to pathology results evaluated images in consensus. Read More

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Giant Ferroelectric Resistance Switching Controlled by a Modulatory Terminal for Low-Power Neuromorphic In-Memory Computing.

Adv Mater 2021 Apr 15:e2008709. Epub 2021 Apr 15.

Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.

Ferroelectrics have been demonstrated as excellent building blocks for high-performance nonvolatile memories, including memristors, which play critical roles in the hardware implementation of artificial synapses and in-memory computing. Here, it is reported that the emerging van der Waals ferroelectric α-In Se can be used to successfully implement heterosynaptic plasticity (a fundamental but rarely emulated synaptic form) and achieve a resistance-switching ratio of heterosynaptic memristors above 10 , which is two orders of magnitude larger than that in other similar devices. The polarization change of ferroelectric α-In Se channel is responsible for the resistance switching at various paired terminals. Read More

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Longitudinal structural brain changes in Friedreich ataxia depend on disease severity: the IMAGE-FRDA study.

J Neurol 2021 Apr 15. Epub 2021 Apr 15.

School of Psychological Sciences and Turner Institute for Brain and Mental Health, Monash University, Clayton Campus, Clayton, VIC, 3800, Australia.

Background: Friedreich ataxia is an inherited neurodegenerative disease, with cerebral and cerebellar pathology evident. Despite an increased understanding of its neuropathology, disease progression in this disease remains poorly understood. This study aimed to characterise longitudinal change in brain structure using a multi-modal approach across cerebral and cerebellar grey and white matter. Read More

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Spatio-temporal feature learning with reservoir computing for T-cell segmentation in live-cell [Formula: see text] fluorescence microscopy.

Sci Rep 2021 Apr 15;11(1):8233. Epub 2021 Apr 15.

Department of Computational Neuroscience, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf (UKE), Martinistrasse 52, 20246, Hamburg, Germany.

Advances in high-resolution live-cell [Formula: see text] imaging enabled subcellular localization of early [Formula: see text] signaling events in T-cells and paved the way to investigate the interplay between receptors and potential target channels in [Formula: see text] release events. The huge amount of acquired data requires efficient, ideally automated image processing pipelines, with cell localization/segmentation as central tasks. Automated segmentation in live-cell cytosolic [Formula: see text] imaging data is, however, challenging due to temporal image intensity fluctuations, low signal-to-noise ratio, and photo-bleaching. Read More

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Acceleration of Brain TOF-MRA with Compressed Sensitivity Encoding: A Multicenter Clinical Study.

AJNR Am J Neuroradiol 2021 Apr 15. Epub 2021 Apr 15.

From the Department of Radiology (J.D., Y.D., Z.Z., J.Y., C.F., Y.L.), Beijing Tiantan Hospital, Capital Medical University, Beijing, China

Background And Purpose: The clinical practice of three-dimensional TOF-MRA, despite its capability in brain artery assessment, has been hampered by the relatively long scan time, while recent developments in fast imaging techniques with random undersampling has shed light on an improved balance between image quality and imaging speed. Our aim was to evaluate the effectiveness of TOF-MRA accelerated by compressed sensitivity encoding and to identify the optimal acceleration factors for routine clinical use.

Materials And Methods: One hundred subjects, enrolled at 5 centers, underwent 8 brain TOF-MRA sequences: 5 sequences using compressed sensitivity encoding with acceleration factors of 2, 4, 6, 8, and 10 (CS2, CS4, CS6, CS8, and CS10), 2 using sensitivity encoding with factors of 2 and 4 (SF2 and SF4), and 1 without acceleration as a reference sequence (RS). Read More

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Image-Guided Percutaneous Pancreatic Duct Drainage: A 10-Year Observational Study.

J Vasc Interv Radiol 2021 Apr 12. Epub 2021 Apr 12.

Professor of Surgery and Cancer, Department of Surgery and Cancer, Imperial College London, Hammersmith Campus, DuCane Road, London W12 0HS, UK.

Purpose: To study the safety, efficacy, and long-term outcomes of percutaneous pancreatic duct drainage (PPDD) for treating pancreatic duct (PD) obstruction.

Materials And Methods: This prospective observational cohort study included 73 patients with PD obstruction between December 2010 and June 2020. Patients underwent PPDD under ultrasound and fluoroscopy guidance, computed tomography (CT) and fluoroscopy guidance, or CT guidance only. Read More

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Robust and efficient single-pixel image classification with nonlinear optics.

Opt Lett 2021 Apr;46(8):1848-1851

We present a hybrid image classifier by feature-sensitive image upconversion, single pixel photodetection, and deep learning, aiming at fast processing of high-resolution images. It uses partial Fourier transform to extract the images' signature features in both the original and Fourier domains, thereby significantly increasing the classification accuracy and robustness. Tested on the Modified National Institute of Standards and Technology handwritten digit images and verified by simulation, it boosts accuracy from 81. Read More

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Super-Resolution Photoacoustic Microscopy Using Structured-Illumination.

IEEE Trans Med Imaging 2021 Apr 15;PP. Epub 2021 Apr 15.

A novel super-resolution volumetric photoacoustic microscopy, based on the theory of structured-illumination, is proposed in this paper. The structured-illumination will be introduced in order to surpass the diffraction limit in a photoacoustic microscopy (PAM) structure. Through optical excitation of the targeted object with a sinusoidal spatial fringe pattern, the object's frequency spectrum is forced to shift in the spatial frequency domain. Read More

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Macrotrabecular-massive hepatocellular carcinoma: imaging identification and prediction based on gadoxetic acid-enhanced magnetic resonance imaging.

Eur Radiol 2021 Apr 15. Epub 2021 Apr 15.

Department of Radiology, West China Hospital, Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, China.

Objectives: To identify image features of macrotrabecular-massive (MTM) hepatocellular carcinoma (HCC) and to determine its role in predicting MTM-HCC.

Methods: Patients who underwent preoperative gadoxetic acid-enhanced MRI and with surgery proven HCC were retrospectively included. Imaging features were assessed according to Liver Imaging Reporting and Data System. Read More

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Assessment of factors affecting washout appearance of hepatocellular carcinoma on CT.

Eur Radiol 2021 Apr 15. Epub 2021 Apr 15.

Department of Radiology, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, South Korea.

Objectives: To identify independent imaging and histopathologic factors that affect washout appearance of hepatocellular carcinoma (HCC) in CT images.

Methods: This retrospective study included 264 patients who had undergone surgical resection for treatment-naïve single HCC between January 2014 and December 2015 and had available preoperative multiphasic CT images. Two reviewers evaluated the CT imaging features of HCC using LI-RADS v2018. Read More

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Differentiation between Clear Cell Sarcoma of the Kidney and Wilms' Tumor with CT.

Korean J Radiol 2021 Apr 1. Epub 2021 Apr 1.

Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea.

Objective: Clear cell sarcoma of the kidney (CCSK) is the second-most common but extremely rare primary renal malignancy in children after Wilms' tumor. The aims of this study were to evaluate the imaging features that could distinguish between CCSK and Wilms' tumor and to assess the features with diagnostic value for identifying CCSK.

Materials And Methods: We reviewed the initial contrast-enhanced abdominal-pelvic CT scans of children with CCSK and Wilms' tumor between 2010 to 2019. Read More

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Comparison of FDG and FMISO uptakes and distributions in head and neck squamous cell cancer tumors.

EJNMMI Res 2021 Apr 14;11(1):38. Epub 2021 Apr 14.

Memorial Sloan-Kettering Cancer Center, New York, NY, USA.

Purpose: Glycolysis is increased by hypoxia, suggesting a possible correlation between the accumulation of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) in malignant tumors and regional hypoxia defined by 1H-1-(3-[18F]fluoro-2-hydroxypropyl)-2-nitroimidazole (FMISO) PET. The aim of this study is to investigate the intra-tumoral spatial distribution and quantitative relationship between FDG and FMISO in a cohort of head and neck squamous cell cancer (HNSCC) patients.

Methods: Twenty HNSCC patients with 20 primary tumors and 19 metastatic lymph nodes (LNs) underwent FDG and FMISO PET within 1 week. Read More

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Radiomic analysis of lung cancer for the assessment of patient prognosis and intratumor heterogeneity.

Radiol Bras 2021 Mar-Apr;54(2):87-93

Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil.

Objective: To determine whether the radiomic features of lung lesions on computed tomography correlate with overall survival in lung cancer patients.

Materials And Methods: This was a retrospective study involving 101 consecutive patients with malignant neoplasms confirmed by biopsy or surgery. On computed tomography images, the lesions were submitted to semi-automated segmentation and were characterized on the basis of 2,465 radiomic variables. Read More

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Risk Factors for Infection and Revision Surgery following Patellar Tendon and Quadriceps Tendon Repairs: An Analysis of 3,442 Patients.

J Knee Surg 2021 Apr 14. Epub 2021 Apr 14.

Department of Orthopaedic Surgery, University of Virginia, Charlottesville, Virginia.

Disruption of the extensor mechanism is debilitating with surgical repair being the accepted treatment. The incidence of infection and reoperation after extensor mechanism repair are not well reported in the literature. Thus, the objective of the current study was to (1) determine the incidence of surgical site infection and reoperation within 1 year of primary extensor mechanism repair and (2) identify independent risk factors for infection and reoperation following patellar and quadriceps tendon repair. Read More

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Protocol Optimization Considerations for Implementing Deep Learning CT Reconstruction.

AJR Am J Roentgenol 2021 Apr 14:1-10. Epub 2021 Apr 14.

GE Healthcare, Waukesha, WI.

Previous advances over filtered back projection (FBP) have incorporated model-based iterative reconstruction. The purpose of this study was to characterize the latest advance in image reconstruction, that is, deep learning. The focus was on applying characterization results of a deep learning approach to decisions about clinical CT protocols. Read More

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The classification of EEG-based winking signals: a transfer learning and random forest pipeline.

PeerJ 2021 31;9:e11182. Epub 2021 Mar 31.

Innovative Manufacturing, Mechatronics and Sports Laboratory, Faculty of Manufacturing and Mechatronics Engineering Technology, Universiti Malaysia Pahang, Pekan, Pahang Darul Makmur, Malaysia.

Brain Computer-Interface (BCI) technology plays a considerable role in the control of rehabilitation or peripheral devices for stroke patients. This is particularly due to their inability to control such devices from their inherent physical limitations after such an attack. More often than not, the control of such devices exploits electroencephalogram (EEG) signals. Read More

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Development of a dynamic imaging method for gravitropism in pea sprouts using clinical magnetic resonance imaging system.

Plant Biotechnol (Tokyo) 2020 Dec;37(4):437-442

Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan.

Although magnetic resonance imaging (MRI) is a useful technique, only a few studies have investigated the dynamic behavior of small subjects using MRI owing to constraints such as experimental space and signal amount. In this study, to acquire high-resolution continuous three-dimensional gravitropism data of pea () sprouts, we developed a small-bore MRI signal receiver coil that can be used in a clinical MRI and adjusted the imaging sequence. It was expected that such an arrangement would improve signal sensitivity and improve the signal-to-noise ratio (SNR) of the acquired image. Read More

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December 2020