scholarly journals Ultra-high resolution, 3-dimensional magnetic resonance imaging of the atherosclerotic vessel wall at clinical 7T

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0241779
Author(s):  
Martin J. Willemink ◽  
Bram F. Coolen ◽  
Hadrien Dyvorne ◽  
Philip M. Robson ◽  
Ilda Bander ◽  
...  
Keyword(s):  
High Resolution ◽  
Image Quality ◽  
Spatial Resolution ◽  
Vessel Wall ◽  
High Field ◽  
High Spatial Resolution ◽  
Black Blood ◽  
Lower Field ◽  
Plaque Area ◽  
Field Strengths

Accurate quantification and characterization of atherosclerotic plaques with MRI requires high spatial resolution acquisitions with excellent image quality. The intrinsically better signal-to-noise ratio (SNR) at high-field clinical 7T compared to the widely employed lower field strengths of 1.5 and 3T may yield significant improvements to vascular MRI. However, 7T atherosclerosis imaging also presents specific challenges, related to local transmit coils and B1 field inhomogeneities, which may overshadow these theoretical gains. We present the development and evaluation of 3D, black-blood, ultra-high resolution vascular MRI on clinical high-field 7T in comparison lower-field 3T. These protocols were applied for in vivo imaging of atherosclerotic rabbits, which are often used for development, testing, and validation of translatable cardiovascular MR protocols. Eight atherosclerotic New Zealand White rabbits were imaged on clinical 7T and 3T MRI scanners using 3D, isotropic, high (0.63 mm3) and ultra-high (0.43 mm3) spatial resolution, black-blood MR sequences with extensive spatial coverage. Following imaging, rabbits were sacrificed for validation using fluorescence imaging and histology. Image quality parameters such as SNR and contrast-to-noise ratio (CNR), as well as morphological and functional plaque measurements (plaque area and permeability) were evaluated at both field strengths. Using the same or comparable imaging parameters, SNR and CNR were in general higher at 7T compared to 3T, with a median (interquartiles) SNR gain of +40.3 (35.3–80.1)%, and a median CNR gain of +68.1 (38.5–95.2)%. Morphological and functional parameters, such as vessel wall area and permeability, were reliably acquired at 7T and correlated significantly with corresponding, widely validated 3T vessel wall MRI measurements. In conclusion, we successfully developed 3D, black-blood, ultra-high spatial resolution vessel wall MRI protocols on a 7T clinical scanner. 7T imaging was in general superior to 3T with respect to image quality, and comparable in terms of plaque area and permeability measurements.

scholarly journals High-Resolution Black-Blood MRI of the Carotid Vessel Wall Using Phased-Array Coils at 1.5 and 3 Tesla1

2005 ◽  
Vol 12 (12) ◽  
pp. 1521-1526 ◽  
Author(s):  
SeshaSailaja Anumula ◽  
Hee Kwon Song ◽  
Alexander C. Wright ◽  
Felix W. Wehrli
Keyword(s):  
High Resolution ◽  
Vessel Wall ◽  
Phased Array ◽  
Black Blood ◽  
Black Blood Mri ◽  
Carotid Vessel Wall ◽  
Phased Array Coils ◽  
Array Coils ◽  
Carotid Vessel

scholarly journals Deriving VIIRS High-Spatial Resolution Water Property Data over Coastal and Inland Waters Using Deep Convolutional Neural Network

2021 ◽  
Vol 13 (10) ◽  
pp. 1944
Author(s):  
Xiaoming Liu ◽  
Menghua Wang
Keyword(s):  
Neural Network ◽  
High Resolution ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Ocean Color ◽  
Super Resolution ◽  
Inland Waters ◽  
Coastal Oceans ◽  
Chl A ◽  
Color Data

The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite has been a reliable source of ocean color data products, including five moderate (M) bands and one imagery (I) band normalized water-leaving radiance spectra nLw(λ). The spatial resolutions of the M-band and I-band nLw(λ) are 750 m and 375 m, respectively. With the technique of convolutional neural network (CNN), the M-band nLw(λ) imagery can be super-resolved from 750 m to 375 m spatial resolution by leveraging the high spatial resolution features of I1-band nLw(λ) data. However, it is also important to enhance the spatial resolution of VIIRS-derived chlorophyll-a (Chl-a) concentration and the water diffuse attenuation coefficient at the wavelength of 490 nm (Kd(490)), as well as other biological and biogeochemical products. In this study, we describe our effort to derive high-resolution Kd(490) and Chl-a data based on super-resolved nLw(λ) images at the VIIRS five M-bands. To improve the network performance over extremely turbid coastal oceans and inland waters, the networks are retrained with a training dataset including ocean color data from the Bohai Sea, Baltic Sea, and La Plata River Estuary, covering water types from clear open oceans to moderately turbid and highly turbid waters. The evaluation results show that the super-resolved Kd(490) image is much sharper than the original one, and has more detailed fine spatial structures. A similar enhancement of finer structures is also found in the super-resolved Chl-a images. Chl-a filaments are much sharper and thinner in the super-resolved image, and some of the very fine spatial features that are not shown in the original images appear in the super-resolved Chl-a imageries. The networks are also applied to four other coastal and inland water regions. The results show that super-resolution occurs mainly on pixels of Chl-a and Kd(490) features, especially on the feature edges and locations with a large spatial gradient. The biases between the original M-band images and super-resolved high-resolution images are small for both Chl-a and Kd(490) in moderately to extremely turbid coastal oceans and inland waters, indicating that the super-resolution process does not change the mean values of the original images.

scholarly journals ZnWO4 Nanoparticle Scintillators for High Resolution X-ray Imaging

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1721
Author(s):  
Heon Yong Jeong ◽  
Hyung San Lim ◽  
Ju Hyuk Lee ◽  
Jun Heo ◽  
Hyun Nam Kim ◽  
...  
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
High Resolution ◽  
Tungsten Oxide ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
Average Size ◽  
And Tungsten

The effect of scintillator particle size on high-resolution X-ray imaging was studied using zinc tungstate (ZnWO4) particles. The ZnWO4 particles were fabricated through a solid-state reaction between zinc oxide and tungsten oxide at various temperatures, producing particles with average sizes of 176.4 nm, 626.7 nm, and 2.127 μm; the zinc oxide and tungsten oxide were created using anodization. The spatial resolutions of high-resolution X-ray images, obtained from utilizing the fabricated particles, were determined: particles with the average size of 176.4 nm produced the highest spatial resolution. The results demonstrate that high spatial resolution can be obtained from ZnWO4 nanoparticle scintillators that minimize optical diffusion by having a particle size that is smaller than the emission wavelength.

scholarly journals 5.17. The NRO CO survey of nearby spiral galaxies

1998 ◽  
Vol 184 ◽  
pp. 245-246 ◽  
Author(s):  
K. Nishiyama ◽  
N. Nakai
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Spiral Galaxies ◽  
High Spatial Resolution ◽  
Molecular Gas ◽  
Characteristic Structure

Our survey observation is high spatial resolution (16″) by NRO observatory 45 m antenna and have many galaxies of sample. This high resolution observations (16″ = 1.6 kpc at 20 Mpc) could be to resolve the some characteristic structure, typical molecular gas disk, arm - interarm and optical bar.

scholarly journals Evaluation of a dedicated dual phased-array surface coil using a black-blood FSE sequence for high resolution MRI of the carotid vessel wall

2002 ◽  
Vol 15 (3) ◽  
pp. 344-351 ◽  
Author(s):  
Mohamed Ouhlous ◽  
Franck Lethimonnier ◽  
Diederik W.J. Dippel ◽  
Marc R.H.M. van Sambeek ◽  
Lambertus C.J. van Heerebeek ◽  
...  
Keyword(s):  
High Resolution ◽  
Vessel Wall ◽  
Phased Array ◽  
Surface Coil ◽  
Black Blood ◽  
High Resolution Mri ◽  
Carotid Vessel Wall ◽  
Carotid Vessel

scholarly journals Observations of the Quiet Sun with 6″ Resolution

1980 ◽  
Vol 86 ◽  
pp. 53-55
Author(s):  
M. R. Kundu ◽  
A. P. Rao ◽  
F. T. Erskine ◽  
J. D. Bregman
Keyword(s):  
High Resolution ◽  
Radio Emission ◽  
Transition Region ◽  
Spatial Resolution ◽  
Radio Telescope ◽  
Solar Radio ◽  
High Spatial Resolution ◽  
Solar Radio Emission ◽  
Quiet Sun ◽  
Millimeter Wavelengths

Solar radio emission at centimeter and millimeter wavelengths originates in the chromosphere and transition region and is a useful probe for the temperature and density in these regions. High spatial resolution observations of the quiet sun provide valuable information on the structure of the solar atmosphere. We have performed high resolution (~ 6″ (E-W) x 15″ (N-S)) observations at 6 cm with the Westerbork Synthesis Radio Telescope (WSRT) in June 1976 in order to search for the radio analog of the supergranulation network and to study the extent and symmetry of limb brightening. The use of the WSRT for high spatial resolution solar mapping has been described by Bregman and Felli (1976), Kundu et al. (1977), and others.

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