Results 71 to 80 of about 317,605 (301)

Accurate hybrid template–based and MR-based attenuation correction using UTE images for simultaneous PET/MR brain imaging applications

BMC Medical Imaging, 2018
Background Attenuation correction is one of the most crucial correction factors for accurate PET data quantitation in hybrid PET/MR scanners, and computing accurate attenuation coefficient maps from MR brain acquisitions is challenging.
Jakub Baran, Zhaolin Chen, Francesco Sforazzini, Nicholas Ferris, Sharna Jamadar, Ben Schmitt, David Faul, Nadim Jon Shah, Marian Cholewa, Gary F. Egan   +9 more
doaj   +1 more source

In-Beam Background Suppression Shield [PDF]

, 2015
The long (3ms) proton pulse of the European Spallation Source (ESS) gives rise to unique and potentially high backgrounds for the instrument suite. In such a source an instrument capabilities will be limited by it's Signal to Noise (S/N) ratio.
Ansell, S., Bentley, P. M., Cai, X. X., DiJulio, D. D., Santoro, V.   +4 more
core   +2 more sources

High‐Resolution MRI Revealed Different Etiology‐Specific Associations With Cerebral Infarction in Adult Moyamoya Vasculopathy

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective High‐resolution MRI enables detailed assessment of intracranial vessel wall pathology in moyamoya vasculopathy. We aimed to classify adult moyamoya vasculopathy etiologies using high‐resolution MRI and to examine subtype‐specific associations between high‐resolution MRI features and ischemic infarction.
Guangsong Han, Jiachun Pan, Yuehui Hong, Xiaoyuan Fan, Ming Yao, Lixin Zhou, Yicheng Zhu, Feng Feng, Jun Ni   +8 more
wiley   +1 more source

The role of the reflection coefficient in precision measurement of ultrasonic attenuation [PDF]

Ultrasonic attenuation measurements using contact, pulse-echo techniques are sensitive to surface roughness and couplant thickness variations. This can reduce considerable inaccuracies in the measurement of the attenuation coefficient for broadband ...
Generazio, E. R.
core   +1 more source

Second coefficient of viscosity in air [PDF]

, 1991
Acoustic attenuation measurements in air were analyzed in order to estimate the second coefficient of viscosity. Data over a temperature range of 11 C to 50 C and at relative humidities between 6 percent and 91 percent were used.
Ash, Robert L., Zheng, Zhonquan, Zuckerwar, Allan J.   +2 more
core   +1 more source

The Effect of Temperature Gradient on Ultrasonic Attenuation [PDF]

, 1973
The effect of temperature gradient on ultrasonic attenuation is estimated based upon the simple phenomenological theory, and it being found that the attenuation coefficient for a CdS crystal is 0.76 dB/cm at temperature gradient 100 K ...
Ishii, Tadao
core   +1 more source

photoelectric attenuation coefficient

, 2014
Citation: 'photoelectric attenuation coefficient' in the IUPAC Compendium of Chemical Terminology, 3rd ed.; International Union of Pure and Applied Chemistry; 2006. Online version 3.0.1, 2019. 10.1351/goldbook.P04602 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms.
openaire   +1 more source

Choroid Plexus Enlargement and USPIO‐Based Inflammatory Feature in Cerebral Small Vessel Disease

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective The choroid plexus (CP) is a key component of the blood–cerebrospinal fluid barrier (BCSFB), but its mechanism of action in cerebral small vessel disease (CSVD) remains unclear. This study investigated CP volume (CPV) alterations and their association with conventional imaging markers in CSVD and explored the underlying role of ...
Yongqiang Qu, Xiaoning Ren, Cuihua Fan, Chun Li, Lijie Zhang, Zaiqiang Zhang, Shaowu Li, Zhongmeng Lai, Bin Cai, Ying Fu, Yi Lin, Zhibao Zhu   +11 more
wiley   +1 more source

Triangular Index Ratio as An Alternative Method to the Alpha Angle for Defining the Presence of Cam Morphology: A Prospective Cohort Study

Arthritis Care &Research, Accepted Article.
Objective Cam morphology, a significant risk factor for hip osteoarthritis, is commonly quantified by the alpha angle (AA). This study aims to explore the potential of the triangular index ratio (TIR) to quantify cam morphology on anteroposterior radiographs by assessing the association between TIR‐defined cam morphology and the development of ...
Jinchi Tang, Fleur Boel, Michiel M. A. van Buuren, Noortje S. Riedstra, Myrthe A. van den Berg, Jos Runhaar, Sita Bierma‐Zeinstra, Rintje Agricola   +7 more
wiley   +1 more source

Frequency dependent ultrasonic attenuation coefficient assessment in fresh tissue

Archives of Acoustics, 2015
The authors discuss the frequency dependent ultrasonic attenuation coefficient for fresh liver and fresh spleen from bovine, porcine and lamb, and fresh pancreas from bovine and futher discuss the role of these attenuation coefficients in terms of their ...
W. D. O'BRIEN, L. A. SEGAL
doaj