Experimental Validation of a Microwave System for Brain Stroke 3-D Imaging

This paper experimentally validates the capability of a microwave prototype device to localize hemorrhages and ischemias within the brain as well as proposes an innovative calibration technique based on the measured data. In the reported experiments, a 3-D human-like head phantom is considered, where the brain is represented either with a homogeneous liquid mimicking brain dielectric properties or with ex vivo calf brains. The microwave imaging (MWI) system works at 1 GHz, and it is realized with a low-complexity architecture formed by an array of twenty-four printed monopole antennas. Each antenna is embedded into the “brick” of a semi-flexible dielectric matching medium, and it is positioned conformal to the head upper part. The imaging algorithm exploits a differential approach and provides 3-D images of the brain region. It employs the singular value decomposition of the discretized scattering operator obtained via accurate numerical models. The MWI system analysis shows promising reconstruction results and extends the device validation.

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A Prototype Microwave System for 3D Brain Stroke Imaging

Sensors ◽

10.3390/s20092607 ◽

2020 ◽

Vol 20 (9) ◽

pp. 2607 ◽

Cited By ~ 4

Author(s):

Jorge A. Tobon Vasquez ◽

Rosa Scapaticci ◽

Giovanna Turvani ◽

Gennaro Bellizzi ◽

David O. Rodriguez-Duarte ◽

...

Keyword(s):

Low Complexity ◽

3D Images ◽

Stroke Imaging ◽

Microwave System ◽

Imaging Approach ◽

Minimum Number ◽

Open Issue ◽

Brain Stroke ◽

Differential Imaging

This work focuses on brain stroke imaging via microwave technology. In particular, the open issue of monitoring patients after stroke onset is addressed here in order to provide clinicians with a tool to control the effectiveness of administered therapies during the follow-up period. In this paper, a novel prototype is presented and characterized. The device is based on a low-complexity architecture which makes use of a minimum number of properly positioned and designed antennas placed on a helmet. It exploits a differential imaging approach and provides 3D images of the stroke. Preliminary experiments involving a 3D phantom filled with brain tissue-mimicking liquid confirm the potential of the technology in imaging a spherical target mimicking a stroke of a radius equal to 1.25 cm.

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Synthesis and pharmacokinetic characterisation of a fluorine-18 labelled brain shuttle peptide fusion dimeric affibody

Scientific Reports ◽

10.1038/s41598-021-82037-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Takahiro Morito ◽

Ryuichi Harada ◽

Ren Iwata ◽

Yiqing Du ◽

Nobuyuki Okamura ◽

...

Keyword(s):

Ex Vivo ◽

Post Injection ◽

Affibody Molecule ◽

Positron Emission ◽

A Cell ◽

Protein Binders ◽

Rapid Clearance ◽

Labelling Method ◽

The Brain ◽

Ex Vivo Study

AbstractBrain positron emission tomography (PET) imaging with radiolabelled proteins is an emerging concept that potentially enables visualization of unique molecular targets in the brain. However, the pharmacokinetics and protein radiolabelling methods remain challenging. Here, we report the performance of an engineered, blood–brain barrier (BBB)-permeable affibody molecule that exhibits rapid clearance from the brain, which was radiolabelled using a unique fluorine-18 labelling method, a cell-free protein radiosynthesis (CFPRS) system. AS69, a small (14 kDa) dimeric affibody molecule that binds to the monomeric and oligomeric states of α-synuclein, was newly designed for brain delivery with an apolipoprotein E (ApoE)-derived brain shuttle peptide as AS69-ApoE (22 kDa). The radiolabelled products 18F-AS69 and 18F-AS69-ApoE were successfully synthesised using the CFPRS system. Notably, 18F-AS69-ApoE showed higher BBB permeability than 18F-AS69 in an ex vivo study at 10 and 30 min post injection and was partially cleared from the brain at 120 min post injection. These results suggest that small, a brain shuttle peptide-fused fluorine-18 labelled protein binders can potentially be utilised for brain molecular imaging.

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Artefact and ablation performance of an MR-conditional high-power microwave system in bovine livers: an ex vivo study

European Radiology Experimental ◽

10.1186/s41747-019-0115-4 ◽

2019 ◽

Vol 3 (1) ◽

Cited By ~ 1

Author(s):

Antonia Grimm ◽

Moritz Winkelmann ◽

Jakob Weiß ◽

Georg Gohla ◽

Gunnar Blumenstock ◽

...

Keyword(s):

High Power ◽

Ex Vivo ◽

Spin Echo ◽

Breath Hold ◽

High Power Microwave ◽

Mr Conditional ◽

Slice Orientation ◽

Microwave System ◽

Post Hoc ◽

Power Microwave

Abstract Background We evaluated a magnetic resonance (MR)-conditional high-power microwave ablation system. Methods An exvivo 1.5-T evaluation was conducted by varying the sequence (T1-weighted volume interpolated breath-hold examination, T1w-VIBE; T1-weighted fast low-angle shot, T1w-FLASH; T2-weighted turbo spin-echo, T2w-TSE), applicator angulation to B0 (A-to-B0), slice orientation, and encoding direction. Tip location error (TLE) and artefact diameters were measured, and influence of imaging parameters was assessed with analysis of variance and post hoc testing. Twenty-four exvivo ablations were conducted in three bovine livers at 80 W and 120 W. Ablation durations were 5, 10, and 15 min. Ablation zones were compared for short-axis diameter (SAD), volume, and sphericity index (SI) with unpaired t test. Results The artefact pattern was similar for all sequences. The shaft artefact (4.4 ± 2.9 mm, mean ± standard deviation) was dependent on the sequence (p = 0.012) and the A-to-B0 (p < 0.001); the largest shaft diameter was measured with T1w-FLASH (6.3 ± 3.4 mm) and with perpendicular A-to-B0 (6.7 ± 2.4 mm). The tip artefact (1.6 ± 0.7 mm) was dependent on A-to-B0 (p = 0.001); TLE was -2.6 ± 1.0 mm. Ablation results at the maximum setting (15 min, 120 W) were SAD = 42.0 ± 1.41 mm; volume = 56.78 ± 3.08 cm3, SI = 0.68 ± 0.05. In all ablations, SI ranged 0.68–0.75 with the smallest SI at 15 min and 120 W (p = 0.048). Conclusion The system produced sufficiently large ablation zones and the artefact was appropriate for MR-guided interventions.

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Two-Step Root-MUSIC for Direction of Arrival Estimation without EVD/SVD Computation

International Journal of Antennas and Propagation ◽

10.1155/2018/9695326 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Feng-Gang Yan ◽

Shuai Liu ◽

Jun Wang ◽

Ming Jin

Keyword(s):

Super Resolution ◽

Direction Of Arrival ◽

Doa Estimation ◽

Low Complexity ◽

Music Algorithm ◽

Correlation Matrices ◽

Noise Subspace ◽

Using Data ◽

Eigen Decomposition ◽

Value Decomposition

Most popular techniques for super-resolution direction of arrival (DOA) estimation rely on an eigen-decomposition (EVD) or a singular value decomposition (SVD) computation to determine the signal/noise subspace, which is computationally expensive for real-time applications. A two-step root multiple signal classification (TS-root-MUSIC) algorithm is proposed to avoid the complex EVD/SVD computation using a uniform linear array (ULA) based on a mild assumption that the number of signals is less than half that of sensors. The ULA is divided into two subarrays, and three noise-free cross-correlation matrices are constructed using data collected by the two subarrays. A low-complexity linear operation is derived to obtain a rough noise subspace for a first-step DOA estimate. The performance is further enhanced in the second step by using the first-step result to renew the previous estimated noise subspace with a slightly increased complexity. The new technique can provide close root mean square error (RMSE) performance to root-MUSIC with reduced computational burden, which are verified by numerical simulations.

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The Hippocratic Doctrine of “the Acute Brain Suffering” as the Brain Stroke

Journal of Stroke and Cerebrovascular Diseases ◽

10.1016/j.jstrokecerebrovasdis.2018.10.017 ◽

2019 ◽

Vol 28 (2) ◽

pp. 412-417 ◽

Cited By ~ 1

Author(s):

Gregory Tsoucalas ◽

Theodore G Papaioannou ◽

Marianna Karamanou

Keyword(s):

Brain Stroke ◽

The Brain

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Toxoplasma gondii injected neurons localize to the cortex and striatum and have altered firing

10.1101/2021.02.18.431839 ◽

2021 ◽

Author(s):

Oscar A. Mendez ◽

Emiliano Flores Machado ◽

Jing Lu ◽

Anita A. Koshy

Keyword(s):

Toxoplasma Gondii ◽

Single Neuron ◽

Latent Infection ◽

Ex Vivo ◽

Medium Spiny Neurons ◽

Patch Clamping ◽

Spiny Neurons ◽

The Brain ◽

Mapping Program

AbstractToxoplasma gondii is an intracellular parasite that causes a long-term latent infection of neurons. Using a custom MATLAB-based mapping program in combination with a mouse model that allows us to permanently mark neurons injected with parasite proteins, we found that Toxoplasma-injected neurons (TINs) are heterogeneously distributed in the brain, primarily localizing to the cortex followed by the striatum. Using immunofluorescence co-localization assays, we determined that cortical TINs are commonly (>50%) excitatory neurons (FoxP2+) and that striatal TINs are often (>65%) medium spiny neurons (MSNs) (FoxP2+). As MSNs have highly characterized electrophysiology, we used ex vivo slices from infected mice to perform single neuron patch-clamping on striatal TINs and neighboring uninfected MSNs (bystander MSNs). These studies demonstrated that TINs have highly abnormal electrophysiology, while the electrophysiology of bystander MSNs was akin to that of MSNs from uninfected mice. Collectively, these data offer new neuroanatomic and electrophysiologic insights into CNS toxoplasmosis.

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Convection-Enhanced Arborizing Catheter System Improves Local/Regional Delivery of Infusates Versus a Single-Port Catheter in Ex Vivo Porcine Brain Tissue

Journal of Engineering and Science in Medical Diagnostics and Therapy ◽

10.1115/1.4048935 ◽

2020 ◽

Vol 4 (1) ◽

Author(s):

Egleide Y. Elenes ◽

Jason N. Mehta ◽

Fang-Chi Hsu ◽

Christopher T. Whitlow ◽

Waldermar Debinski ◽

...

Keyword(s):

Standard Treatment ◽

Single Port ◽

Ex Vivo ◽

Volume Of Distribution ◽

Port Catheter ◽

Convection Enhanced Delivery ◽

Alternative Approach ◽

The Brain ◽

Regional Delivery ◽

Porcine Brain Tissue

Abstract Standard treatment for glioblastoma is noncurative and only partially effective. Convection-enhanced delivery (CED) was developed as an alternative approach for effective loco-regional delivery of drugs via a small catheter inserted into the diseased brain. However, previous CED clinical trials revealed the need for improved catheters for controlled and satisfactory distribution of therapeutics. In this study, the arborizing catheter, consisting of six infusion ports, was compared to a reflux-preventing single-port catheter. Infusions of iohexol at a flow rate of 1 μL/min/microneedle were performed, using the arborizing catheter on one hemisphere and a single-port catheter on the contralateral hemisphere of excised pig brains. The volume dispersed (Vd) of the contrast agent was quantified for each catheter. Vd for the arborizing catheter was significantly higher than for the single-port catheter, 2235.8 ± 569.7 mm3 and 382.2 ± 243.0 mm3, respectively (n = 7). Minimal reflux was observed; however, high Vd values were achieved with the arborizing catheter. With simultaneous infusion using multiple ports of the arborizing catheter, high Vd was achieved at a low infusion rate. Thus, the arborizing catheter promises a highly desirable large volume of distribution of drugs delivered to the brain for the purpose of treating brain tumors.

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New Technologies of Motor Control and Rehabilitation

Reabilitacijos mokslai slauga kineziterapija ergoterapija ◽

10.33607/rmske.v1i1.890 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Albertas Skurvydas

Keyword(s):

Motor Control ◽

New Technologies ◽

Modern Science ◽

Computational Approach ◽

Neural Cells ◽

Motor Rehabilitation ◽

Principal Mechanism ◽

Brain Stroke ◽

Computational Paradigm ◽

The Brain

Modern paradigms of motor control and rehabilitation are analyzed in the paper. Two main paradigms, i. e. computational approach and dynamical system approach are engaged in rivalry in motor control and learning research at present. From the standpoint of computational paradigm the principal mechanism of motor control and learning consists in the ability of the brain “to calculate” (acting as some kind of biological computer). According to the paradigm of dynamical systems the mechanism of motor control is time dependent. In other words, it can be different each time. The main principles of motor control and properties of movements are given considerable attention in the paper. Besides, modern methods of motor rehabilitation after stroke are emphasized in the paper. Fitting of neuroprosthesis and restoration of damaged neural cells are significant maiden steps in modern science. The scientists are engaged in search for: a) constraining such mechanism prosthesis that would submit to the efforts of human will and b) restoring neural cells damaged because of the brain stroke suffered.Keywords: motor control, rehabilitation, stroke.

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