Arterial water spin labels. Medical search. Frequent questions

In continuous arterial spin labeling (CASL), the blood water is inverted as it flows through the brain in one plane. (wikipedia.org)
This is rectified in pseudo-continuous arterial spin labeling (pCASL), where a single long pulse is replaced with multiple (up to a thousand) millisecond pulses. (wikipedia.org)
Continuous arterial spin labeling at the human common carotid artery: The influence of transit times. (mpg.de)
Continuous arterial spin labeling using a local magnetic field gradient coil. (mpg.de)
Technological aspects of human brain perfusion imaging by continuous arterial spin labeling. (mpg.de)

This review primarily focuses on several noninvasive magnetic resonance imaging (MRI) techniques, encompassing perivascular space (PVS) imaging, diffusion tensor image analysis along the PVS, arterial spin labeling, chemical exchange saturation transfer, and intravoxel incoherent motion. (qigonginstitute.org)
Chemical Exchange Saturation Transfer and Arterial Spin Labeling: How Similar Pulse Sequences detect Different Phenomena. (lu.se)

In order to properly scale the perfusion values into cerebral blood flow units (CBF, ml/100g/1 min), a separate proton density map with the same parameters (but longer TR to fully relax the blood spins) is recommended to be acquired as well. (wikipedia.org)
Comparison of cerebral blood flow acquired by simultaneous [15O]water positron emission tomography and arterial spin labeling magnetic resonance imaging. (ox.ac.uk)
Until recently, no direct comparison between [(15)O]water positron emission tomography (PET) and arterial spin labeling (ASL) for measuring cerebral blood flow (CBF) was possible. (ox.ac.uk)
His current focus is on developing and validating signal processing strategies for arterial spin labeling (ASL) and studying changes in cerebral blood flow (CBF) patterns in different neurodegenerative diseases. (upenn.edu)
The performance of MRI-based cerebral blood flow measurements in acute and subacute stroke compared with 15O-water positron emission tomography identification of penumbral flow. (mpg.de)
Aim: To determine the effects of creatine, homoarginine and resveratrol on cerebral blood flow by arterial spin labeling (ASL) in MR Methods and supervision: mice deficient in creatine, wild type mice and Alzheimer model mice will be the animals involved in this study. (radboudimaging.nl)

Endogenous contrast methods (e.g., arterial spin labeling, ASL) and contrast agent bolus tracking methods (dynamic susceptibility contrast and dynamic contrast enhanced MRI) are some of the methods available to researchers using the Center. (barrowneuro.org)
The aim of my main research is to develop and validate MRI pulse sequences and post-processing tools for assessment of perfusion-related parameters using gd-based contrast agents (Dynamic Susceptibility Contrast MRI - DSC-MRI) and non-invasive methods (Arterial Spin Labelling - ASL and Intra Voxel Incoherent Motion - IVIM). (lu.se)

Perfusion MRI using an arterial spin labeling technique showed regional hypoperfusion in arcAβ compared to non-transgenic controls, which was alleviated by noscapine treatment. (uzh.ch)
Unlike a volunteer, the rate of delivery of perfusate (the water-based liquid that circulates the QASPER phantom) is consistent every time, therefore the QASPER phantom is a stable reference that can be used to assess system variability for ASL perfusion MRI measurements. (goldstandardphantoms.com)
I am co-inventor of arterial spin labeled perfusion MRI, which has been translated to clinical use, but remains a powerful research tool for measuring regional brain function. (upenn.edu)
Arterial spin-labeled (ASL) perfusion MRI quantifies blood flow to diagnose disorders in diseases like Alzheimer's. (qmenta.com)

Arterial spin labeling (ASL), also known as arterial spin tagging, is a magnetic resonance imaging technique used to quantify cerebral blood perfusion by labelling blood water as it flows throughout the brain. (wikipedia.org)
ASL specifically refers to magnetic labeling of arterial blood below or in the imaging slab, without the need of gadolinium contrast. (wikipedia.org)
A 3T MR-BrainPET scanner was used for the simultaneous acquisition of pseudo-continuous ASL (pCASL) magnetic resonance imaging (MRI) and [(15)O]water PET. (ox.ac.uk)
Arterial spin labeling (ASL) is a noncontrast perfusion imaging method that relies on the magnetic labeling of arterial water. (radiologykey.com)
Is there a change in water proton density associated with functional magnetic resonance imaging? (mpg.de)
As an original technique, a cine arterial spin labeling (ASL) cardiovascular magnetic resonance approach is demonstrated to be able to produce dynamic MBF maps across the cardiac cycle in rats. (biomedcentral.com)
Xu F, Zhu D, Fan H, Lu H, Liu D, Li W, Qin Q. Magnetic resonance angiography and perfusion mapping by arterial spin labeling using Fourier transform-based velocity-selective pulse trains: Examination on a commercial perfusion phantom. (goldstandardphantoms.com)
diffusion MRI Diffusion-weighted magnetic resonance imaging (DWI or DW-MRI) is the use of specific MRI sequences as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR images. (theinfolist.com)
Differences in magnetic properties between arterial (oxygen-rich) and venous (oxygen-poor) blood provided this link. (theinfolist.com)
Dr. Ware's research focuses on the application of translational neuroscience imaging techniques such as structural morphometry, diffusion imaging, functional magnetic resonance imaging and arterial spin labeling perfusion to the study and clinical evaluation of traumatic brain injury. (upenn.edu)

Arterial Spin Labeling (ASL) is an MR technique using the water in arterial blood as an endogenous contrast agent to non-invasively evaluate perfusion. (siemens-healthineers.com)
Arterial spin-labeling MR imaging is a technique relying on labeled endogenous water as a tracer. (ingentaconnect.com)

Many ASL-specific toolboxes have been developed to assist in ASL analysis, such as BASIL (Bayesian inference for arterial spin labelling MRI), part of the FSL neuroimaging package and also Ze Wang's ASL toolbox (using MATLAB) to assist in the subtraction and averaging of the tagged/control pairs. (wikipedia.org)
His specific areas of expertise include physiological modeling, arterial spin labeling, Bayesian inference, PET/MRI, and artificial intelligence. (stanford.edu)

By measuring the signal difference between 2 sets of acquisitions (labeling and control), arterial spin-labeling MR imaging calculates cerebral perfusion in a quantitative manner. (ingentaconnect.com)
N-myristoylated proteins from VACV and the host were metabolically labelled with myristic acid alkyne during infection using quantitative chemical proteomics. (cdc.gov)

In pulse arterial spin labeling (PASL), blood water is inverted as it passes through a labeling slab (of 15 to 20 cm) instead of a plane. (wikipedia.org)
This method combines the high labeling efficiency of CASL with the reduced hardware demands of PASL. (radiologykey.com)

Advanced MR methods can measure and quantify motion as subtle as water diffusion as well as flow velocity in 3 dimensions, either in vivo or in physical models using a programmable MR compatible pump. (barrowneuro.org)
To quantify perfusion, the Arterial Spin Labeling (ASL) technique uses water protons as a freely diffusible contrast agent. (biomedcentral.com)

This study presents results of CBF measurements recorded simultaneously with [(15)O]water and ASL. (ox.ac.uk)
QASPER ( Q uantitative A rterial S pin Labelling Pe rfusion R eference) is a calibration and quality assurance standard for MRI perfusion measurements using Arterial Spin Labelling (ASL). (goldstandardphantoms.com)
Frequency-dependent conductivity measurements between 4.5 and 35 GHz are reported in the spin-density-wave (SDW) state of the linear-chain organic conductor (TMTSF) 2 P F 6, where TMTSF denotes tetramethyltetraselenafulvalenium. (srinivassridhar.com)

A deliberately long, labyrinthine flow path ensures that none of the labelled bolus is recirculated before the label decays and ensures fully developed equilibrium magnetisation. (goldstandardphantoms.com)

Among the variety of imaging methods, MRI has quickly gathered attention because it can reveal different types of brain tissues based on the physical properties of body composition (e.g. the content of water molecules) as a 'natural' contrast agent. (pocketdentistry.com)
A family of MR angiography techniques that utilize fresh spins to depict the contrast in blood vessels as an alternative to an injection of an exogenous contrast agent. (medical.canon)

Influence of the arterial input function on absolute and relative perfusion-weighted imaging penumbral flow detection: A validation with 15o-water positron emission tomography. (mpg.de)
MRI perfusion maps in acute stroke validated with 15O-water positron emission tomography. (mpg.de)

More recently, however, a hybrid approach, known as pulsed continuous or pseudocontinuous ASL (pcASL), has become popular, in which many short-duration RF pulses can be used to effectively label arterial water over a longer duration. (radiologykey.com)
This feature visualizes blood flows labelled with IR pulses using the 3D BASG sequence and does not require ECG/pulse wave synchronization. (fujifilm.com)
Selectively applying IR pulses upstream in the blood vessels to be visualized and acquiring images when the blood flow is Null enables the incoming labelled blood flow to be visualized as Black Blood. (fujifilm.com)
Therefore, by capturing images twice with selective IR pulses ON and OFF and acquiring a subtraction image, blood flows labelled with IR pulses will be visualized as a high-intensity area. (fujifilm.com)

Arterial spin labeling utilizes the water molecules circulating with the brain, and using a radiofrequency pulse, tracks the blood water as it circulates throughout the brain. (wikipedia.org)
In particular, Fresh Blood Imaging (FBI), Flow Spoiled FBI (FS-FBI) and Time-Spatial Labeling Inversion Pulse (Time-SLIP), are discussed. (medical.canon)

Background: CEST is a new MR contrast method, making use of irradiation of protons on compounds exchangeable with water protons. (radboudimaging.nl)
In collaboration with the TU Twente several functionalized polymers (e.g. drug carrying, targeted to tissue receptors etc) will be produced with water exchangeable protons. (radboudimaging.nl)

Images are acquired without (control) and with (label) application of arterial inversion at the site of the labeling plane. (radiologykey.com)
Efficiency of flow-driven adiabatic spin inversion under realistic experimental conditions: A computer simulation. (mpg.de)
In the conventional approach to arterial spin labeling in the rodent heart, the relative difference in the apparent T 1 relaxation times corresponding to selective and non-selective inversion is related to perfusion via a two compartment model of tissue. (biomedcentral.com)
Slice-selective inversion causes signal enhancement due to in-flow of thermally stabilized spins whereas global inversion is insensitive to flow. (biomedcentral.com)

Diseases such as diabetes, atherosclerosis, cardiomyopathies, and arterial hypertension result in functional and morphologic microvascular alterations, which may precede clinical signs and symptoms. (biomedcentral.com)
Clinical evaluation of an arterial-spin-labeling product sequence in steno-occlusive disease of the brain. (mpg.de)

Velocity selective arterial spin labeling is advantageous in a population where blood flow may be impeded (e.g. stroke), because the labeling occurs closer to the capillaries. (wikipedia.org)
It defines the time duration for spins to travel from the labeling plane or volume to the imaged slices and is typically between 1500 and 2000 ms. Because ischemic stroke is defined by reduced flow via proximal routes, any remaining flow to the tissue is often supplied via collateral routes, which leads to increased delays between the labeling of the spins and the arrival of those spins in the imaged voxel. (radiologykey.com)
A PET-guided framework supports a multiple arterial input functions approach in DSC-MRI in acute stroke. (mpg.de)

DTI - Diffusion Tensor Imaging uses MRI to measure the microscopic movement of water molecules. (wakehealth.edu)
Diffusion MRI is similar to BOLD fMRI but provides contrast based on the magnitude of diffusion of water molecules in the brain. (theinfolist.com)

In the cardiac implementation of ASL, spin labeling is generally done within the detection slice. (biomedcentral.com)

This allows the post labeling decay to be shorter. (wikipedia.org)
the longer the delay between the labeling and the imaging, the more SNR penalty is paid due to T1-related decay of the labeled spins. (radiologykey.com)

Mapping of arterial transit time by intravascular signal selection. (mpg.de)
Flow-weighted arterial transit time mapping of the human brain. (mpg.de)

Her current work focuses on implementation of arterial spin labeling (ASL)-derived biomarkers in studying cerebrovascular contributions of cognitive impairment and dementia. (upenn.edu)

3D diffusion tensor imaging with 2D navigated turbo spin echo. (mpg.de)
Observation of Myelin Water at Ultra-Short Echo Time by Longitudinal Relaxographic Imaging with Spin-Echo Center-out EPI (DEPICTING). (mpg.de)

This leads to a higher labelling efficiency. (wikipedia.org)

Using an integrated, hybrid MR-PET a direct simultaneous comparison between ASL and [(15)O]water PET became possible for the first time so that temporal, physiologic, and functional variations were avoided. (ox.ac.uk)
The Effects of Acutely Administered 3,4-Methylenedioxymethamphetamine on Spontaneous Brain Function in Healthy Volunteers Measured with Arterial Spin Labeling and Blood Oxygen Level-Dependent Resting State Functional Connectivity. (entheomedicine.org)

PIQE can be used on 2D Fast Spin Echo (FSE) sequences, at both 1.5 and 3T, especially when SNR is low but more sharpness is needed. (medical.canon)

T1 based myelin water detection at 3 Tesla using phased-array adaptive reconstruction and long range TI sampling. (mpg.de)

After a period of time in microseconds (enough to allow the blood to circulate through the brain), a 'label' image is captured. (wikipedia.org)
These methodologies provide valuable insights into the dynamics of interstitial fluid, water permeability across the blood-brain barrier, and cerebrospinal fluid flow within the cerebral parenchyma. (qigonginstitute.org)
In vivo measurement of the anisotropic diffusion of water is used to generate images of white matter tracts in the brain. (barrowneuro.org)
Background: We recently discovered profound effects of creatine on various body functions in mice including blood flow in the brain (measured by arterial spin labeling). (radboudimaging.nl)

Transgenic arcAβ mice, and non-transgenic littermates of 14 months-of-age were either treated with the bradykinin receptors 1 and 2 blocker noscapine or received normal drinking water as control over 3 months ( = 8-11/group) and all mice were assessed using fMRI at the end of the treatment period. (uzh.ch)

Drawbacks include reduced signal-to-noise and high sensitivity to arterial transit delays. (radiologykey.com)

A 'control' image is also acquired before the labeling of the blood water. (wikipedia.org)
In this schematic, the inverted blood in the label image is shown in blue. (radiologykey.com)
The label image has slightly less signal intensity due to the infusion of inverted magnetization provided by the inflowing labeled blood. (radiologykey.com)

Recent studies link neuroinflammation in neurological diseases to white matter free water modeling from diffusion MRI. (qmenta.com)

Can sediment data be used to predict alkalinity and base cation chemistry of surface waters? (fcdo.gov.uk)

Regardless of the labeling approach, images are then acquired with and without labeling after allowing time for the labeled blood to pass from the site of labeling into the tissue of interest. (radiologykey.com)

although longer label times lead to a larger buildup of labeled spins in the voxel, the increased time may be better spent on acquiring additional pairs of label and control images for signal averaging. (radiologykey.com)

In order to increase SNR, collections of control and label images can be averaged. (wikipedia.org)

Sildenafil used to treat pulmonary arterial hypertension (high blood pressure in the pulmonary artery). (who.int)

Velocity selective arterial spin labeling is a strategy that still requires validation. (wikipedia.org)

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