Imaging Science in Medicine

2013 ◽  
Author(s):  
William R. Hendee
Keyword(s):  
Imaging Science

scholarly journals Bi-caudate ratio as a MRI marker of white matter atrophy in multiple sclerosis and ischemic leukocencephalopathy

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Dena Serag ◽  
Eman Ragab
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Surrogate Marker ◽  
Normal Subjects ◽  
Subjective Assessment ◽  
Linear Measurement ◽  
Control Group ◽  
Imaging Science ◽  
The Difference ◽  
Sensitivity Specificity

Abstract Background Brain atrophy measurement is now a cornerstone in basic neuro-imaging science. While assessment of white matter atrophy by visual inspection is subjective, volumetric approaches are time-consuming and not often feasible. Bi-caudate ratio represents a linear surrogate parameter of brain volume that can be derived from standard imaging sequences. This study highlights the value of the bi-caudate ratio (BCR) as a MRI marker of white matter atrophy in patients with multiple sclerosis and ischemic leukoencephalopathy and set a cut-off value to differentiate between patients with white matter atrophy and normal subjects. Results A total of 115 patients (54 males and 61 females) diagnosed with white matter leukoencephalopathy (MS in 51 patients and ischemic leukoencephalopathy in 64 patients) were included. Another group of 60 subjects with a normal white matter signal was recruited as a control group. BCR for the patient group ranged from 0.13 to 0.27 (mean (± SD) = 0.16 ± 0.02), while for the control group, it ranged from 0.05 mm to 0.13 (mean (± SD) = 0.09 ± 0.01). The difference between the two groups was statistically significant (P value < 0.001). A cut-off value of 0.13 was used to differentiate between the BCR in both patients and control groups with sensitivity, specificity, and accuracy of 99.2%, 100%, and 99%, respectively. The difference in BCR for patients diagnosed with MS and ischemic leukoencephalopathy was also statistically significant (P value < 0.001). Conclusion The bi-caudate ratio represents a linear measurement of subcortical atrophy that can be useful as a surrogate marker of global supra-tentorial white matter atrophy instead of the usually performed visual and therefore subjective assessment. It is an easily obtained measure that can be performed without complex time-consuming volumetric studies. Our findings also revealed that the BCR is higher in patients with ischemic leukoencephalopathy than in patients with MS.

scholarly journals Rapid Single Image-Based DTM Estimation from ExoMars TGO CaSSIS Images Using Generative Adversarial U-Nets

2021 ◽  
Vol 13 (15) ◽  
pp. 2877
Author(s):  
Yu Tao ◽  
Siting Xiong ◽  
Susan J. Conway ◽  
Jan-Peter Muller ◽  
Anthony Guimpier ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Imaging System ◽  
Landing Site ◽  
Parameter Tuning ◽  
Processing Parameters ◽  
Input Image ◽  
Large Area ◽  
Laser Altimeter ◽  
Imaging Science

The lack of adequate stereo coverage and where available, lengthy processing time, various artefacts, and unsatisfactory quality and complexity of automating the selection of the best set of processing parameters, have long been big barriers for large-area planetary 3D mapping. In this paper, we propose a deep learning-based solution, called MADNet (Multi-scale generative Adversarial u-net with Dense convolutional and up-projection blocks), that avoids or resolves all of the above issues. We demonstrate the wide applicability of this technique with the ExoMars Trace Gas Orbiter Colour and Stereo Surface Imaging System (CaSSIS) 4.6 m/pixel images on Mars. Only a single input image and a coarse global 3D reference are required, without knowing any camera models or imaging parameters, to produce high-quality and high-resolution full-strip Digital Terrain Models (DTMs) in a few seconds. In this paper, we discuss technical details of the MADNet system and provide detailed comparisons and assessments of the results. The resultant MADNet 8 m/pixel CaSSIS DTMs are qualitatively very similar to the 1 m/pixel HiRISE DTMs. The resultant MADNet CaSSIS DTMs display excellent agreement with nested Mars Reconnaissance Orbiter Context Camera (CTX), Mars Express’s High-Resolution Stereo Camera (HRSC), and Mars Orbiter Laser Altimeter (MOLA) DTMs at large-scale, and meanwhile, show fairly good correlation with the High-Resolution Imaging Science Experiment (HiRISE) DTMs for fine-scale details. In addition, we show how MADNet outperforms traditional photogrammetric methods, both on speed and quality, for other datasets like HRSC, CTX, and HiRISE, without any parameter tuning or re-training of the model. We demonstrate the results for Oxia Planum (the landing site of the European Space Agency’s Rosalind Franklin ExoMars rover 2023) and a couple of sites of high scientific interest.

scholarly journals Patents and Pasteur: Why new metrics may point to imaging science as a model for innovation

2014 ◽  
Vol 72 (5) ◽  
pp. 1199-1200
Author(s):  
Michael J. Kalutkiewicz ◽  
Richard L. Ehman ◽  
Matt A. Bernstein
Keyword(s):  
Imaging Science

scholarly journals Improving the Diagnosis and Management of Neuroendocrine Tumors: Utilizing New Advances in Biomarker and Molecular Imaging Science

2013 ◽  
Vol 98 (1) ◽  
pp. 16-30 ◽  
Author(s):  
Valeria Giandomenico ◽  
Irvin M. Modlin ◽  
Fredrik Pontén ◽  
Mats Nilsson ◽  
Ulf Landegren ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Neuroendocrine Tumors ◽  
Diagnosis And Management ◽  
Imaging Science

scholarly journals Avalanches of the martian north polar cap

2020 ◽  
Author(s):  
Patricio Becerra ◽  
Susan Conway ◽  
Nicholas Thomas ◽  
Keyword(s):  
Polar Regions ◽  
Martian Surface ◽  
Polar Cap ◽  
Water Ice ◽  
The North ◽  
Imaging Science ◽  
Resolution Imaging ◽  
North Polar ◽  
Gas Expansion ◽  
Trigger Mechanisms

&lt;p&gt;In 2008, the High Resolution Imaging Science Experiment (HiRISE) on board NASA&amp;#8217;s MRO fortuitously captured several discrete clouds of material in the process of cascading down a steep scarp of the water-ice-rich north polar layered deposits (NPLD). The events were only seen during a period of ~4 weeks, near the onset of martian northern spring in 2008, when the seasonal cover of CO2 is beginning to sublimate from the north polar regions. Russell et al. [1] analyzed the morphology of the clouds, inferring that the particles involved were mechanically analogous to terrestrial &amp;#8220;dry, loose snow or dust&amp;#8221;, so that the events were similar to terrestrial &amp;#8220;powder avalanches&amp;#8221; [2]. HiRISE confirmed the seasonality of avalanche occurrence the following spring, and continued to capture between 30 and 50 avalanches per season (fig. 1b,c) between 2008 and 2019, for a total of 7 Mars Years (MY29&amp;#8211;MY35) of continuous scarp monitoring.&lt;/p&gt;&lt;p&gt;In this work we will present statistics on these events, in an attempt to quantify their effect on the mass balance of the NPLD, and with respect to competing processes such as viscous deformation and stress-induced block falls that do not trigger avalanches [3,4]. We also use a 1D thermal model [5] to investigate the sources and trigger mechanisms of these events. The model tracks the accumulation and ablation of seasonal CO2 frost on a martian surface. Russell et al. [1] support an initiation through gas-expansion related to the presence of CO2 frost on the scarp. Therefore the amount of frost that lingers on different sections of the model scarp at the observed time of the avalanches will provide evidence either for or against this particular mechanism. We will present preliminary results and discuss their implications.&lt;/p&gt;&lt;p&gt;References: [1] P. Russell et al. (2008) Geophys. Res. Lett. 35, L23204. [2] D. McClung, P.A. Schaerer (2006), Mountaineers, Seattle Wash. [3] Sori, M. M., et al., Geophys. Res. Lett., 43. [4] Byrne et al. (2016), 6th Int. Conf. Mars Polar Sci. Exploration [4] C. M. Dundas and S. Byrne (2010) Icarus 206, 716.&lt;/p&gt;

scholarly journals AN INVESTIGATION OF THE HYPOTHESES FOR FORMATION OF THE PLATY-RIDGED-POLYGONIZED TERRAIN IN ELYSIUM PLANITIA, MARS

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 205-211
Author(s):  
Z. Yue ◽  
S. Gou ◽  
G. Michael ◽  
K. Di ◽  
H. Xie ◽  
...  
Keyword(s):  
Martian Surface ◽  
Basalt Lava ◽  
Regional Environment ◽  
Low Viscosity ◽  
Quantitative Measurements ◽  
Scientific Exploration ◽  
Pack Ice ◽  
Crater Counting ◽  
Imaging Science ◽  
Resolution Imaging

The origin of the platy-ridged-polygonized (PRP) terrains on Martian surface has long been debated. The terrain has generally been classified as water, pack ice, or basalt lava related flow. The crater counting results of the PRP terrains suggest they are geologically very young; therefore, they are significant in understanding the recent evolution of Mars. This work evaluated the current hypotheses through detailed analysis of the distribution and microtopographies with the High Resolution Imaging Science Experiment (HiRISE) images for the PRP terrains in Elysium Planitia, Mars. Quantitative measurements and statistics of the typical features of the PRP terrains were also made. In addition, we also found an analog site in Tarim Basin in Xinjiang, China. Our results suggest that mud flow is responsible for the formation of the PRP terrains on the Mars surface, although the hypothesis of low-viscosity basalt lava floods cannot be completely excluded. This finding implies that a regional environment suitable for liquid water may have existed in recent geologic time, which has great importance for future Mars scientific exploration.

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