scholarly journals Real-Time Multi-Modal Sensing and Feedback for Catheterization in Porcine Tissue

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 273
Author(s):  
Christoff M. Heunis ◽  
Filip Šuligoj ◽  
Carlos Fambuena Santos ◽  
Sarthak Misra
Keyword(s):  
Real Time ◽  
3D Visualization ◽  
X Rays ◽  
X Ray ◽  
Porcine Tissue ◽  
X Ray Imaging ◽  
Tissue Surfaces ◽  
Fbg Sensors ◽  
3D Surface Imaging ◽  
Diagnostic Technologies

Objective: In this study, we introduce a multi-modal sensing and feedback framework aimed at assisting clinicians during endovascular surgeries and catheterization procedures. This framework utilizes state-of-the-art imaging and sensing sub-systems to produce a 3D visualization of an endovascular catheter and surrounding vasculature without the need for intra-operative X-rays. Methods: The catheterization experiments within this study are conducted inside a porcine limb undergoing motions. A hybrid position-force controller of a robotically-actuated ultrasound (US) transducer for uneven porcine tissue surfaces is introduced. The tissue, vasculature, and catheter are visualized by integrated real-time US images, 3D surface imaging, and Fiber Bragg Grating (FBG) sensors. Results: During externally-induced limb motions, the vasculature and catheter can be reliably reconstructed at mean accuracies of 1.9±0.3 mm and 0.82±0.21 mm, respectively. Conclusions: The conventional use of intra-operative X-ray imaging to visualize instruments and vasculature in the human body can be reduced by employing improved diagnostic technologies that do not operate via ionizing radiation or nephrotoxic contrast agents. Significance: The presented multi-modal framework enables the radiation-free and accurate reconstruction of significant tissues and instruments involved in catheterization procedures.

Defects of Platelet Function Recognized by X-Ray Imaging and Scanning Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 610-613
Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Biology ◽  
Imaging Technique ◽  
Human Platelets ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Complex Phenomena ◽  
Scanning Electron

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).

A Magnetically Guided Self‐Rolled Microrobot for Targeted Drug Delivery, Real‐Time X‐Ray Imaging, and Microrobot Retrieval

2021 ◽  
pp. 2001681
Author(s):  
Kim Tien Nguyen ◽  
Gwangjun Go ◽  
Zhen Jin ◽  
Bobby Aditya Darmawan ◽  
Ami Yoo ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Real Time ◽  
Targeted Drug Delivery ◽  
X Ray ◽  
X Ray Imaging ◽  
Targeted Drug

An investigation into the extent of Lodox imaging usage in South Africa: Radiographer’s perspective

2021 ◽  
Author(s):  
Julius Muchui Thambura ◽  
Jeanette G.E du Plessis ◽  
Cheryl M E McCrindle ◽  
Tanita Cronje
Keyword(s):  
South Africa ◽  
Waiting Times ◽  
Cross Sectional Study ◽  
Trauma Patients ◽  
X Rays ◽  
Online Questionnaire ◽  
Cross Sectional ◽  
Imaging Protocol ◽  
X Ray ◽  
X Ray Imaging

Abstract Introduction Anecdotal evidence suggests that medical professionals in trauma units are requesting additional regional images using conventional x-ray systems, even after trauma patients have undergone full-body Lodox scans. Patients are then exposed to additional radiation, additional waiting times and an increased medical bill. This study aimed at investigating the extent to which Lodox systems were used in trauma units (n=28) in South Africa. Method In this descriptive cross-sectional study, the researcher invited one radiographer from the 28 hospitals in South Africa that use Lodox systems. Radiographers who were most experienced in using the Lodox system completed an online questionnaire. Results Twenty (71.43% n=20) out of twenty-eight radiographers responded. Most hospitals (90%, n=18) were referring patients for additional conventional x-ray images. Radiographers indicated that conventional x-rays were requested for the chest (27.80%, 10/36), the abdomen (16.67%, 6/36), the spine (13.89%, 5/36) and the extremities and skull (19.44%, 7/36). Additionally, radiographers reported using Lodox to perform procedures and examinations usually performed on conventional x-ray systems when conventional x-ray systems were not operational. Conclusion Currently, it is not clear if the use of conventional x-ray imaging following Lodox is necessary, but the results suggest that the practice is commonplace, with healthcare workers in most hospitals (90%, n=18) requesting additional x-ray imaging. The researcher thus recommends that an imaging protocol for Lodox imaging systems should be developed to guide the referral of the patients for further imaging.

scholarly journals Truncated Inception Net: COVID-19 Outbreak Screening using Chest X-rays

2020 ◽  
Author(s):  
Dipayan Das ◽  
KC Santosh ◽  
Umapada Pal
Keyword(s):  
Neural Network ◽  
World Wide ◽  
Imaging Techniques ◽  
Imaging Systems ◽  
Ct Scans ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Proposed Model ◽  
Different Types

Abstract Since December 2019, the Coronavirus Disease (COVID-19) pandemic has caused world-wide turmoil in less than a couple of months, and the infection, caused by SARS-CoV-2, is spreading at an unprecedented rate. AI-driven tools are used to identify Coronavirus outbreaks as well as forecast their nature of spread, where imaging techniques are widely used, such as CT scans and chest X-rays (CXRs). In this paper, motivated by the fact that X-ray imaging systems are more prevalent and cheaper than CT scan systems, a deep learning-based Convolutional Neural Network (CNN) model, which we call Truncated Inception Net, is proposed to screen COVID-19 positive CXRs from other non-COVID and/or healthy cases. To validate our proposal, six different types of datasets were employed by taking the following CXRs: COVID-19 positive, Pneumonia positive, Tuberculosis positive, and healthy cases into account. The proposed model achieved an accuracy of 99.96% (AUC of 1.0) in classifying COVID- 19 positive cases from combined Pneumonia and healthy cases. Similarly, it achieved an accuracy of 99.92% (AUC of 0.99) in classifying COVID-19 positive cases from combined Pneumonia, Tuberculosis and healthy CXRs. To the best of our knowledge, as of now, the achieved results outperform the existing AI-driven tools for screening COVID-19 using CXRs.

scholarly journals Megavoltage X-Ray Imaging Based on Cerenkov Effect: A New Application of Optical Fibres to Radiation Therapy

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
A. Teymurazyan ◽  
G. Pang
Keyword(s):  
Optical Fibres ◽  
X Rays ◽  
Modulation Transfer ◽  
Imaging Device ◽  
Active Matrix ◽  
X Ray ◽  
X Ray Imaging ◽  
Order Of Magnitude ◽  
Detection Quantum Efficiency ◽  
Cerenkov Effect

A Monte Carlo simulation was used to study imaging and dosimetric characteristics of a novel design of megavoltage (MV) X-ray detectors for radiotherapy applications. The new design uses Cerenkov effect to convert X-ray energy absorbed in optical fibres into light for MV X-ray imaging. The proposed detector consists of a matrix of optical fibres aligned with the incident X rays and coupled to an active matrix flat-panel imager (AMFPI) for image readout. Properties, such as modulation transfer function, detection quantum efficiency (DQE), and energy response of the detector, were investigated. It has been shown that the proposed detector can have a zero-frequency DQE more than an order of magnitude higher than that of current electronic portal imaging device (EPID) systems and yet a spatial resolution comparable to that of video-based EPIDs. The proposed detector is also less sensitive to scattered X rays from patients than current EPIDs.

scholarly journals Exploiting coherence for real-time studies by single-bunch imaging

2014 ◽  
Vol 21 (4) ◽  
pp. 815-818 ◽  
Author(s):  
A. Rack ◽  
M. Scheel ◽  
L. Hardy ◽  
C. Curfs ◽  
A. Bonnin ◽  
...  
Keyword(s):  
Real Time ◽  
European Synchrotron Radiation Facility ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Bunch Length ◽  
X Ray ◽  
Aqueous Foam ◽  
Insertion Device ◽  
X Ray Imaging ◽  
Absorption Contrast

First real-time studies of ultra-fast processes by single-bunch imaging at the European Synchrotron Radiation Facility are reported. By operating the storage ring of the ESRF in single-bunch mode with its correspondingly increased electron bunch charge density per singlet, the polychromatic photon flux density at insertion-device beamlines is sufficient to capture hard X-ray images exploiting the light from a single bunch (the corresponding bunch length is 140 ps FWHM). Hard X-ray imaging with absorption contrast as well as phase contrast in combination with large propagation distances is demonstrated using spatial samplings of 11 µm and 35 µm pixel size. The images acquired allow one to track crack propagation in a bursting piece of glass, breaking of an electrical fuse as well as cell wall rupture in an aqueous foam. Future developments and their potential in the frame of the proposed Phase II of the ESRF Upgrade Program are discussed.

scholarly journals Optimization of the energy for Breast monochromatic absorption X-ray Computed Tomography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pasquale Delogu ◽  
Vittorio Di Trapani ◽  
Luca Brombal ◽  
Giovanni Mettivier ◽  
Angelo Taibi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Imaging Techniques ◽  
Fixed Dose ◽  
X Rays ◽  
Reconstruction Algorithms ◽  
Contrast Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
X Ray Computed ◽  
Dose Levels

Abstract The limits of mammography have led to an increasing interest on possible alternatives such as the breast Computed Tomography (bCT). The common goal of all X-ray imaging techniques is to achieve the optimal contrast resolution, measured through the Contrast to Noise Ratio (CNR), while minimizing the radiological risks, quantified by the dose. Both dose and CNR depend on the energy and the intensity of the X-rays employed for the specific imaging technique. Some attempts to determine an optimal energy for bCT have suggested the range 22 keV–34 keV, some others instead suggested the range 50 keV–60 keV depending on the parameters considered in the study. Recent experimental works, based on the use of monochromatic radiation and breast specimens, show that energies around 32 keV give better image quality respect to setups based on higher energies. In this paper we report a systematic study aiming at defining the range of energies that maximizes the CNR at fixed dose in bCT. The study evaluates several compositions and diameters of the breast and includes various reconstruction algorithms as well as different dose levels. The results show that a good compromise between CNR and dose is obtained using energies around 28 keV.

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