scholarly journals MR ENTEROGRAPHY: AN EMERGENT TECHNIQUE FOR CHARACTERIZATION OF SMALL BOWEL LESIONS IN ONCOLOGICAL AND NON-ONCOLOGY DISEASES

2018 ◽  
Vol 4 (4) ◽  
Author(s):  
Waqas Ahmad ◽  
Iram Zaheer ◽  
Imran Khalid Niazi ◽  
Khurram Aftab Mufti
Keyword(s):  
Small Bowel ◽  
Imaging Technique ◽  
Contrast Material ◽  
Three Dimensional ◽  
Mr Enterography ◽  
Breath Hold ◽  
Diffusion Weighted Images ◽  
Before And After ◽  
Computed Tomography Enterography

Small bowel is not easily accessed by endoscope and diagnosis of its pathology relies on clinical assessment and imaging. Traditional contrast studies have the disadvantage of not including the mural and extramural details. This is best seen with magnetic resonance enterography (MRE) which is rapidly replacing computed tomography enterography due to better soft tissue resolution and lack of ionizing radiation. Comprehensive MRE requires axial and coronal T1- and T2-WI, high-resolution diffusion-weighted images, fat-suppressed three-dimensional T1-W breath-hold gradient-echo images of the abdomen, and pelvis before and after intravenous gadolinium-based contrast material administration. MRE is the preferred imaging technique for small bowel pathology due to its ability to show mural and extramural details which allow differentiation in acute, active, and chronicity of changes. Being radiation free, there is no age limitation for its use.

THE GEOMETRICAL CHARACTERIZATION OF NEURAL ACTIVITY DISPLAYS A SENSITIVITY TO CONVULSANTS

1991 ◽  
Vol 01 (01) ◽  
pp. 253-259 ◽  
Author(s):  
I. D. ZIMMERMAN ◽  
P. E. RAPP ◽  
A. I. MEES
Keyword(s):  
Interspike Interval ◽  
Three Dimensional ◽  
Interval Data ◽  
Time Intervals ◽  
Geometrical Characterization ◽  
Single Nerve ◽  
Before And After ◽  
The Mean ◽  
Standard Techniques

Direct application of a drop of penicillin to the brain's surface can elicit brain electrical activity similar to that seen in some forms of epilepsy. The procedure has therefore become one of the standard techniques in the experimental investigation of epilepsy. The time intervals between action potentials, called the interspike intervals, were measured from single nerve cells in the cerebral cortex of the rat before and after local administration of penicillin. The resulting interspike interval data were examined by elementary statistical procedures and by embedding the data in two- and three-dimensional spaces. The mean interspike interval did not change significantly in response to penicillin. In contrast, the geometrical characterization displayed a dramatic sensitivity to the drug.

Three-Dimensional Structural Characterization of Nonwoven Fabrics

2012 ◽  
Vol 18 (6) ◽  
pp. 1368-1379 ◽  
Author(s):  
Lalith B. Suragani Venu ◽  
Eunkyoung Shim ◽  
Nagendra Anantharamaiah ◽  
Behnam Pourdeyhimi
Keyword(s):  
High Speed ◽  
Imaging Technique ◽  
Low Cost ◽  
Three Dimensional ◽  
Complex Nature ◽  
Volumetric Imaging ◽  
Analysis Techniques ◽  
Nonwoven Fabrics ◽  
Nonwoven Materials

AbstractNonwoven materials are found in a gamut of critical applications. This is partly due to the fact that these structures can be produced at high speed and engineered to deliver unique functionality at low cost. The behavior of these materials is highly dependent on alignment of fibers within the structure. The ability to characterize and also to control the structure is important, but very challenging due to the complex nature of the structures. Thus, to date, focus has been placed mainly on two-dimensional analysis techniques for describing the behavior of nonwovens. This article demonstrates the utility of three-dimensional (3D) digital volumetric imaging technique for visualizing and characterizing a complex 3D class of nonwoven structures produced by hydroentanglement.

scholarly journals New-onset lesions on MRI-DWI and cerebral blood flow changes on 3D-pCASL after carotid artery stenting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wen-Xin Wang ◽  
Ting Wang ◽  
Lin Ma ◽  
Zheng-Hui Sun ◽  
Ge-Sheng Wang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Carotid Artery Stenting ◽  
Three Dimensional ◽  
Diffusion Weighted Images ◽  
Parietal Lobes ◽  
Before And After ◽  
Continuous Arterial Spin Labeling ◽  
New Onset

AbstractThis study aimed to investigate the relationship between the new-onset hyperintense lesions on diffusion-weighted images (DWI) and the changes of cerebral blood flow (CBF) before and after carotid artery stenting (CAS) in patients with symptomatic unilateral carotid artery stenosis. Twenty-four patients with symptomatic unilateral carotid stenosis (50–99%) were enrolled. Routine head magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling were taken 7 days before the surgery and for four consecutive days post CAS. While the incidence of new DWI lesions were high (17/24, 70.8%) and 176 lesions were observed among the 17 cases, there was only one subject showing the symptoms. The majority of the lesions were located at the cortex/subcortex of the ipsilateral frontal and parietal lobes (60.8%) with 92.6% of the lesions size being less than 3 mm. The CBFs in this area were significantly higher than that of the temporal lobe on the first 3 days post stenting (p < 0.05). No periprocedural CBF differences were observed between the two groups, however, the micro-embolism group presented decreased relative CBF in frontal and parietal lobes prior to stenting compared with the non-embolism group. The systolic blood pressure in the micro-embolism group at discharge was significantly lower than that at admission. The high incidence rate of micro-embolism in patients receiving CAS may not be the result of direct changes of hemodynamics in the brain but rather the loss of CBF regulation due to long-term hypoperfusion prior to the stenting.

scholarly journals The role of a novel magnetic resonance imaging sequence in the evaluation of the fetal skeleton: a pilot study

2018 ◽  
Vol 51 (5) ◽  
pp. 303-307 ◽  
Author(s):  
Renata do Amaral Nogueira ◽  
Heron Werner Júnior ◽  
Pedro Daltro ◽  
Glaucia Macedo Lima ◽  
Adauto Dutra Barbosa ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Three Dimensional ◽  
Fetal Mri ◽  
Breath Hold ◽  
Resonance Imaging ◽  
Full Characterization ◽  
Magnetic Resonance Imaging Mri

Abstract Objective: We aimed to study the role of magnetic resonance imaging (MRI), including a novel MRI sequence-the modified volumetric interpolated breath-hold examination (VIBE)-in the characterization of the fetal skeleton. This novel sequence was useful for reconstructing three-dimensional images of the skeleton. Materials and Methods: We enrolled 22 pregnant women whose fetuses had shown congenital abnormalities on ultrasound examinations. The women underwent prenatal fetal MRI in a 1.5-T scanner with a T2-weighted modified VIBE sequence. Three-dimensional reconstructions of the fetal skeleton were performed manually on the instrument itself or via an interactive pen-tablet workstation. Results: Three-dimensional reconstructions of the fetal skeleton were performed after the acquisition of modified VIBE MRI sequences, and it was possible to characterize the fetal skeleton in all MRI examinations. Conclusion: A detailed evaluation of the three-dimensional reconstructions of fetal skeleton performed after acquisition of a modified VIBE MRI sequence allowed a full characterization of the skeleton. However, improvements to the proposed sequence should be addressed in future studies.

scholarly journals Polarization-Sensitive Digital Holographic Imaging for Characterization of Microscopic Samples: Recent Advances and Perspectives

2020 ◽  
Vol 10 (13) ◽  
pp. 4520
Author(s):  
Giuseppe Coppola ◽  
Maria Antonietta Ferrara
Keyword(s):  
Quantitative Evaluation ◽  
State Of The Art ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Three Dimensional Reconstruction ◽  
Comprehensive Review ◽  
Holographic Imaging ◽  
Dimensional Reconstruction ◽  
Micrometer Scale

Polarization-sensitive digital holographic imaging (PS-DHI) is a recent imaging technique based on interference among several polarized optical beams. PS-DHI allows simultaneous quantitative three-dimensional reconstruction and quantitative evaluation of polarization properties of a given sample with micrometer scale resolution. Since this technique is very fast and does not require labels/markers, it finds application in several fields, from biology to microelectronics and micro-photonics. In this paper, a comprehensive review of the state-of-the-art of PS-DHI techniques, the theoretical principles, and important applications are reported.

scholarly journals Some Contributions for Antenna 3D Far Field Characterization at Terahertz

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1438
Author(s):  
Laurent Le Coq ◽  
Nicolas Mézières ◽  
Paul Leroy ◽  
Benjamin Fuchs
Keyword(s):  
Three Dimensional ◽  
Far Field ◽  
Compact Antenna ◽  
Field Patterns ◽  
Millimeter Wave Range ◽  
Before And After ◽  
Wave Range ◽  
Terahertz Frequencies ◽  
The Impact

The three-dimensional (3D) characterization of antenna far field patterns at terahertz frequencies is addressed. This task is challenging, because the phase of the electric field is difficult to measure accurately and reliably. From the sub-millimeter wave range, the small wavelength indeed significantly increases the impact of mechanical and electrical errors. Models and procedures to estimate these errors are proposed to mitigate their effects. The 3D far field patterns of a circularly polarized horn measured at 300 GHz and a multibeam pillbox antenna at 270 GHz are shown. The agreement between the 3D measurements and the two-dimensional (2D) patterns of reference as well as the radiated pattern before and after correction demonstrates the interest of the proposed approach and experimentally validate the proposed error estimation procedures. The methodology can be applied to direct far field measurement facilities as well as compact antenna test ranges.

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