Results 171 to 180 of about 1,409,623 (251)

Next Generation 7 Tesla Arterial Spin Labeling With Rotated Spiral Acquisition Enables Mesoscale Resolution in 3D Brain Perfusion and Functional MRI

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To achieve high resolution (≤ 1 mm isotropic) whole‐brain perfusion imaging at 7 T with next generation ASL pulse sequence, reconstruction algorithm, and MRI hardware. Methods We capitalized on three major innovations: (1) FLASH‐based pseudo‐Continuous ASL (pCASL) sequence with rotated golden‐angle stack‐of‐spirals (rGA‐SoS) sampling; (
Chenyang Zhao, Fanhua Guo, Zidong Yang, Xingfeng Shao, Samantha J. Ma, Alexander J. S. Beckett, An T. Vu, David A. Feinberg, Danny J. J. Wang   +8 more
wiley   +1 more source

Pale Fire and Old Norse Literature [PDF]

, 2017
Antonsson, HT
core  

Modeling the Intermediate Flow Regime in Flow‐Compensated Intravoxel Incoherent Motion MRI

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose The intravoxel incoherent motion (IVIM) model is commonly used to separate the effects of motion related to diffusion and blood microcirculation (perfusion) on the MR signal. Depending on the encoding time (T), it is possible to probe the different temporal regimes of blood motion, which resemble a ballistic flow at short T and a ...
Louise Rosenqvist, Mikael Montelius, Isabella M. Björkman‐Burtscher, Elina Petersson, Maria Ljungberg, Oscar Jalnefjord   +5 more
wiley   +1 more source

Toward Super‐Resolution Reconstruction of Diffusion–Relaxation MRI Using Slice Excitation With Random Overlap (SERO)

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose Diffusion MRI probes tissue microstructure, but low SNR and limited resolution hinder detection of features and parameter estimates. We introduce slice excitation with random overlap (SERO), which enables variable repetition times (TRs) and diffusion weighting within a single shot.
Felix Mortensen, Jakub Jurek, Jens Sjölund, Geraline Vis, Ronnie Wirestam, Malwina Molendowska, Andrzej Materka, Filip Szczepankiewicz   +7 more
wiley   +1 more source

Respiratory Motion‐Corrected Model‐Based 3D Water‐Fat MRA of the Thorax at 0.55 T

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose The goal of this study was to develop a 5‐min 3D MRA acquisition at 0.55 T with predictable scan time, 100% data efficiency, and robust water‐fat separation. Methods For full data efficiency, the proposed method combined self‐gating with retrospective motion correction while ensuring a predictable 5‐min scan time.
Robert Stoll, Christoph Kolbitsch, Michaela Schmidt, Marcel Dominik Nickel, Tobias Schaeffter, Daniel Giese   +5 more
wiley   +1 more source

Ultrafast Blood T1 Measurement Using Golden Angle Rotated Spiral k‐t Sparse Parallel Imaging (GASSP): Evaluations in Both Pre‐ and Post‐Contrast Conditions

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose Blood T1 is a key parameter for hemodynamic quantification in both non‐contrast‐ and contrast‐enhanced imaging. Individual vessel T1 has been measured using a modified Look–Locker scheme with multi‐shot EPI or FLASH in high spatial resolution, requiring ∼1 min.
Zechen Xu, Feng Xu, Qin Qin, Dan Zhu
wiley   +1 more source

Spectral Representation of Neurochemicals With Phase, Frequency Offset, and Lineshape Invariance: Application to JPRESS for In Vivo Concentration and T2 Mapping by Deep Learning

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose Using artificial intelligence neural networks to generate a representation that maps the input directly to neurochemical concentrations and metabolite‐level average transverse relaxation times (T2). Methods The proposed model used time‐domain JPRESS data as input and was trained to be invariant to phase shifts, frequency offsets, and ...
Yan Zhang, Jun Shen
wiley   +1 more source

Numerical Insights Into the Resistance Reduction Mechanisms of Forward Tapered Transoms in High‐Speed Catamaran: A Computational Fluid Dynamics‐Based Study

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT This study investigates the hydrodynamic influence of forward transom tapering on a displacement catamaran hull using computational fluid dynamics (CFD) simulations. Five taper configurations ranging from a vertical transom base design to a fully tapered stern (1.00B) were evaluated over a wide Froude number range (Fr = .3 to 1.0).
Chalermkiat Nuchturee, Chairat Napasaksri, Ramil Kesvarakul, Sarawuth Srinakaew   +3 more
wiley   +1 more source

Key gaps remain in the definition and application of keystone species concepts for fisheries management: A systematic scoping review

People and Nature, EarlyView.
Abstract A keystone species is one whose influence is disproportionate to its abundance, the absence of which would change the dynamics of an ecological or human community. Despite its widespread use in the scientific literature, there is a limited understanding of how the keystone concept is defined or measured, or applied in practice, and especially ...
Natasha R. Serrao, Prateep Kumar Nayak, Jason M. Rae, Derek Armitage, Simon C. Courtenay, Chris C. Wilson   +5 more
wiley   +1 more source

Subsurface Investigations of Cryo‐Hydrogeological Features in a High Arctic Catchment Under Transition

Permafrost and Periglacial Processes, EarlyView.
ABSTRACT In this study, the internal structure and seasonal variations of cryo‐hydrogeological features were investigated in the Fuglebekken catchment, located near the Polish Polar Station Hornsund in Svalbard. Over a few years, rising air temperatures and intensified water circulation have significantly altered the distribution, extent, and state of ...
Wawrzyniak Tomasz, Oryński Szymon, Marciniak Artur, Osuch Marzena   +3 more
wiley   +1 more source