Vessel detection based on dual-operator log-pol top-hat filter

2020 ◽  
Author(s):  
Lei Xu ◽  
Ze Wang ◽  
Chunming He ◽  
Guosheng Lu ◽  
Lizhen Deng
Keyword(s):  
Dual Operator ◽  
Vessel Detection

A Comparative Study of Different Blood Vessel Detection on Retinal Images

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Wan Azani Mustafa ◽  
◽  
Ahmad Syauqi Mahmud ◽  
Muhammad Zaid Aihsan ◽  
M. Saifizi ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Comparative Study ◽  
Retinal Images ◽  
Blood Vessel Detection ◽  
Vessel Detection

scholarly journals Constraints on quasinormal modes and bounds for critical points from pole-skipping

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Navid Abbasi ◽  
Matthias Kaminski
Keyword(s):  
Critical Points ◽  
Thermal State ◽  
Quasinormal Modes ◽  
Scalar Perturbation ◽  
Black Brane ◽  
Massive Scalar ◽  
Dual Operator ◽  
Conformal Dimension ◽  
Scalar Operator ◽  
First Time

Abstract We consider a holographic thermal state and perturb it by a scalar operator whose associated real-time Green’s function has only gapped poles. These gapped poles correspond to the non-hydrodynamic quasinormal modes of a massive scalar perturbation around a Schwarzschild black brane. Relations between pole-skipping points, critical points and quasinormal modes in general emerge when the mass of the scalar and hence the dual operator dimension is varied. First, this novel analysis reveals a relation between the location of a mode in the infinite tower of quasinormal modes and the number of pole-skipping points constraining its dispersion relation at imaginary momenta. Second, for the first time, we consider the radii of convergence of the derivative expansions about the gapped quasinormal modes. These convergence radii turn out to be bounded from above by the set of all pole-skipping points. Furthermore, a transition between two distinct classes of critical points occurs at a particular value for the conformal dimension, implying close relations between critical points and pole-skipping points in one of those two classes. We show numerically that all of our results are also true for gapped modes of vector and tensor operators.

Abstract WP55: Through Thick and Thin: Improved Aspects Grading and Dense Vessel Detection Using Simple Ncct Post-processing

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
James W Evans ◽  
Sadanand Dey ◽  
Muneer Eesa ◽  
Prasanna Eswaradass ◽  
Ronda Lun ◽  
...  
Keyword(s):  
Maximum Intensity Projection ◽  
Improve Patient Care ◽  
Weighted Kappa ◽  
Slice Thickness ◽  
Post Processing ◽  
Rater Reliability ◽  
Thin Slice ◽  
Vessel Detection ◽  
Contrast Ct ◽  
Processing Techniques

Introduction: Assessing Alberta Stroke Program Early CT Score (ASPECTS) and identifying hyperdense arteries on non-contrast CT (NCCT) are important components of decision-making in acute stroke. Conventional practice uses 5mm averaged slice thickness NCCT for interpretation of these features. We have systematically evaluated several post processing techniques on NCCT to determine if there is improved reliability in identification of ASPECTS and hyperdense artery. Methodology: We assessed four post-processing techniques on NCCT namely (1) 5mm averaged thickness (2) Minimum Intensity Projection (mIP) - 5mm thickness (3) thin slices (0.625mm) and (4) Maximum Intensity Projection (MIP) - 5mm thickness (Figure 1). Three raters (student, fellow and expert) independently assessed 100 NCCT scans from the PRoveIT database. All scans were read at four different times 10-14 days apart. At each time-point the post processing modality was changed and the patient order randomized. Information on side of suspected infarction was provided. Raters were asked to score ASPECTS and identify presence of hyperdense artery at each reading. Inter-rater reliability was assessed using Intra-cluster correlation (ICC) for ASPECTS and weighted kappa (wKap) for hyperdense artery. Results: The highest inter-rater reliability was found with the MIP technique (ICC 0.42; p<0.001), followed by 5 mm average, mIP and thin slice respectively (ICC 0.33, 0.32, 0.20; all p<0.01). Highest agreement for hyperdense vessel detection was noted with thin slice (wKap 0.30; p<0.001) followed by Average, MIPs and mIPs respectively (wKap 0.25, 0.18, 0.13; all p <0.05). Conclusion: The use of MIP images for ASPECTS grading and thin images for hyperdense vessel detection improves reliability on NCCT. These simple processing steps are easily available on any modern scanner and may help improve patient care.

scholarly journals A Dual Operator View of Habitual Behavior Reflecting Cortical and Striatal Dynamics

Neuron ◽  
2013 ◽  
Vol 79 (2) ◽  
pp. 361-374 ◽  
Author(s):  
Kyle S. Smith ◽  
Ann M. Graybiel
Keyword(s):  
Dual Operator ◽  
Habitual Behavior

scholarly journals Multipliers and Dual Operator Algebras

2001 ◽  
Vol 183 (2) ◽  
pp. 498-525 ◽  
Author(s):  
David P. Blecher
Keyword(s):  
Operator Algebras ◽  
Dual Operator

scholarly journals A non-parametric vessel detection method for complex vascular structures

2009 ◽  
Vol 13 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Xiaoning Qian ◽  
Matthew P. Brennan ◽  
Donald P. Dione ◽  
Wawrzyniec L. Dobrucki ◽  
Marcel P. Jackowski ◽  
...  
Keyword(s):  
Detection Method ◽  
Vessel Detection ◽  
Vascular Structures ◽  
Non Parametric
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