Three-dimensional line-scan intensity ratio sensing

1992 ◽  
Author(s):  
Israel Amir ◽  
Frank P. Higgins
Keyword(s):  
Intensity Ratio ◽  
Three Dimensional ◽  
Line Scan

Signal intensity pattern of the normal oculomotor nerve on contrast-enhanced 3D FLAIR at 3.0 T MRI

2020 ◽  
pp. 197140092097091
Author(s):  
Thiparom Sananmuang ◽  
Chanonporn Boonsiriwattanakul ◽  
Theeraphol Panyaping
Keyword(s):  
White Matter ◽  
Signal Intensity ◽  
Intensity Ratio ◽  
Grey Matter ◽  
Three Dimensional ◽  
Oculomotor Nerve ◽  
Inversion Recovery ◽  
Signal Intensity Ratio ◽  
Contrast Enhanced ◽  
Fluid Attenuated Inversion Recovery

Purpose The aim of this study was to depict the signal intensity pattern of the normal oculomotor nerve demonstrated on contrast-enhanced three-dimensional fluid-attenuated inversion recovery images. Materials and methods Eighty-one patients were included in the study. Contrast-enhanced three-dimensional fluid-attenuated inversion recovery images with magnetisation-prepared rapid acquisition were reconstructed and evaluated in the coronal plane. The signal intensity of the cisternal segment of the oculomotor nerve was graded into a visual scale of 1 to 5 as compared to the white matter, grey matter and the pituitary stalk. The signal intensity ratio of the oculomotor nerve was consequently measured. Results By using the visual scale, more than half of the oculomotor nerves showed higher signal intensity than the grey matter signal on contrast-enhanced three-dimensional fluid-attenuated inversion recovery images (59.3–80.2%). It can demonstrate a signal intensity similar to the pituitary stalk (14.8%) by visualisation. None of them showed signal intensity equal to the normal white matter signal. By signal intensity measurement, the mean signal intensity ratio of oculomotor nerves to white matter equals 1.54±0.20 (95% confidence interval (CI) 1.51–1.57); mean signal intensity ratio to grey matter equals 1.16±0.15 (95% CI 1.14–1.18); mean signal intensity ratio to the pituitary stalk equals 0.68±0.10 (95% CI 0.64–0.70). Conclusions The normal oculomotor nerve visualised on contrast-enhanced three-dimensional fluid-attenuated inversion recovery images has a higher signal intensity than the white matter and may have a signal intensity similar to the grey matter or the pituitary stalk. The high signal intensity of the oculomotor nerve in contrast-enhanced three-dimensional fluid-attenuated inversion recovery should not be misinterpreted as a pathology.

Three-dimensional line-scan imaging system for robotic measurement

1996 ◽  
Author(s):  
Richard S. Petty ◽  
Simon X. Godber ◽  
J. Paul O. Evans ◽  
McDonald Robinson
Keyword(s):  
Imaging System ◽  
Three Dimensional ◽  
Line Scan

Diffusion Tensor Imaging and 3D Tractography of the Cervical Spinal Cord Using the ECG-Gated Line-Scan Technique

2007 ◽  
Vol 20 (5) ◽  
pp. 574-579 ◽  
Author(s):  
M. Hori ◽  
K. Ishigame ◽  
S. Aoki ◽  
H. Kumagai ◽  
T. Araki
Keyword(s):  
Spinal Cord ◽  
Clinical Symptoms ◽  
Diffusion Tensor ◽  
Cervical Spinal Cord ◽  
Three Dimensional ◽  
Acquisition Time ◽  
Clinical Use ◽  
Ecg Gating ◽  
Line Scan

Diffusion tensor (DT) magnetic resonance (MR) imaging in addition to conventional MR images provide valuable information on the brain. This study compared line scan DT imaging with and without the ECG-gating technique to estimate clinical usefulness of the line scan diffusion tensor image (LSDTI) with ECG-gating in evaluating spinal cord diseases in vivo. First, five healthy volunteers participated in the comparison study. LSDWI was performed in three to five sagittal sections with a pulsed-field-gradient diffusion preparation pulse employing two different b-values (0 and 700 s/mm2) along six directions. Apparent diffusion coefficient (ADC) maps and fractional anisotropy (FA) were calculated and three-dimensional tract reconstruction and color schemes of the spinal cord were obtained. Image quality and the acquisition time of each LSDTI were compared. Second, LSDTI with ECG-gating was performed in eighteen patients with cervical spinal cord disorders and evaluated by two neuroradiologists. Images with the ECG-gated technique were all superior to those without ECG—gating. Mean extended time for LSDTI with ECG-gating was approximately two minutes. In clinical use, the ADC and FA of spinal cord in patients with cervical spondylotic myelopathy statically changed. Moreover, demonstration of fibers was correlated with clinical symptoms. ECG-gating technique is preferable to LSDTI. The ADC and FA measurements and 3D fiber tracking of LSDTI with ECG-gating are promising methods to estimate cervical spinal cord pathology in clinical use.

The Investigation of Arch Model Acting in Mass-Flow Hoppers

2012 ◽  
Vol 508 ◽  
pp. 135-140 ◽  
Author(s):  
Jie Guo ◽  
Alan W. Roberts ◽  
Jan Dirk Prigge
Keyword(s):  
Mass Flow ◽  
Three Dimensional ◽  
Surface Profile ◽  
Experimental Results ◽  
Arch Model ◽  
Test Results ◽  
Arch Models ◽  
Plane Flow ◽  
Line Scan ◽  
Laser Line Scan

This paper presents the experimental results of mass-flow hopper arch geometry investigation, which was conducted using a variable geometry plane-flow bin. The cohesive arches formed under different critical outlet openings and hopper half-angles were measured using a 360° two-dimensional laser line scan system. This system was employed to obtain the complete surface profile of each arch across the width of the outlet by moving the rotating laser along the total length of the outlet. The test results were analyzed using Matlab, adopting stationary wavelet transformation de-noising to decrease the signal noise generated during the testing process. The geometric data for each single line scan was smoothed and combined to present a three-dimensional arch surface profile shown to be in good agreement with the observed experimental arch profiles. The angle η at the intersection of the arch with the hopper walls was then calculated by running a Matlab program and a new angle η' is introduced to the arch shape study. The detailed results are discussed in the paper. Arch geometry models, such as the parabolic arc and circular arc arch models developed, respectively, by Walker [ and Enstad [ are reviewed and their relevance is discussed based on the experimental results presented in this paper.

scholarly journals Effect of Scanning Strategy During Selective Laser Melting on Surface Topography, Porosity, and Microstructure of Additively Manufactured Ti-6Al-4V

2019 ◽  
Vol 9 (24) ◽  
pp. 5554 ◽  
Author(s):  
Emilie Hørdum Valente ◽  
Carsten Gundlach ◽  
Thomas L. Christiansen ◽  
Marcel A. J. Somers
Keyword(s):  
Selective Laser Melting ◽  
Surface Texture ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Total Porosity ◽  
Laser Melting ◽  
Scanning Strategy ◽  
Bottom Part ◽  
Line Scan ◽  
Surface Measurements

The effect of the scanning strategy during selective laser melting (SLM) of Ti-6Al-4V was investigated. An optimized cellular scan strategy (island scan modeled) was compared to a simple cellular scan strategy (island scan stripes) and a simple antiparallel line scanning strategy (line scan). Surface texture was investigated by optical three-dimensional (3D) surface measurements, which when combined with light optical microscopy (LOM), revealed deflections caused by the thermal stresses during the build process. Elevated edges caused by the edge-effect dominate the surface texture of all investigated specimens. The scanning strategy determines the surface texture, and the lowest surface roughness was obtained by the line scan strategy. Porosity was investigated with X-ray computed tomography-imaging. Mainly spherical porosity was observed for the line scan and island scan modeled specimens, while the island scan stripes strategy showed more lack-of-fusion defects and a higher total porosity amount. Microstructure was investigated with LOM and scanning electron microscopy (SEM). The microstructure in Ti-6Al-4V was largely martensitic α’ and prior β grains. The morphology is different for the various scan strategies, and decomposition of α’ into lamellar α/β was observed in the bottom part of the island scan specimen. Accordingly, the hardness decreased in the decomposed part of the specimen.

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