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https://www.readbyqxmd.com/read/29341002/preclinical-arterial-spin-labeling-measurement-of-cerebral-blood-flow
#1
Eric R Muir
Magnetic resonance imaging has been utilized as a quantitative and noninvasive method to image blood flow. Arterial spin labeling (ASL) is an MRI technique that images blood flow using arterial blood water as an endogenous tracer. Herein we describe the use of ASL to measure cerebral blood flow completely noninvasively in rodents, including methods, analysis, and important considerations when utilizing this technique.
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29333914/hybrid-pet-mri-imaging-in-healthy-unsedated-newborn-infants-with-quantitative-rcbf-measurements-using-15o-water-pet
#2
Julie B Andersen, Ulrich Lindberg, Oline V Olesen, Didier Benoit, Claes N Ladefoged, Henrik Bw Larsson, Liselotte Højgaard, Gorm Greisen, Ian Law
In this study, a new hybrid PET/MRI method for quantitative regional cerebral blood flow (rCBF) measurements in healthy newborn infants was assessed and the low values of rCBF in white matter previously obtained by arterial spin labeling (ASL) were tested. Four healthy full-term newborn subjects were scanned in a PET/MRI scanner during natural sleep after median intravenous injection of 14 MBq 15O-water. Regional CBF was quantified using a one-tissue-compartment model employing an image-derived input function (IDIF) from the left ventricle...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/29315770/diffusion-sensitivity-of-3d-grase-in-arterial-spin-labeling-perfusion
#3
Xiang He, Kenneth Wengler, Mark E Schweitzer
PURPOSE: To evaluate the role of true diffusion and flow-related pseudodiffusion in cerebral blood flow (CBF) quantification using arterial spin labeling (ASL) with single-shot or segmented 3D gradient and spin echo (GRASE) readouts. THEORY: The extended phase graph (EPG) algorithm, originally designed to model the effects of T1 /T2 relaxation and true diffusion in MRI acquisitions utilizing multiple refocusing RF pulses, was augmented (aEPG). This augmentation accounted for flow-related pseudodiffusion attenuation of intravascular MRI signal in the k-space domain during 3D-GRASE acquisition, which leads to blur along the partition direction in the image domain...
January 7, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29305164/recent-progress-in-asl
#4
REVIEW
Luis Hernandez-Garcia, Anish Lahiri, Jonas Schollenberger
This article aims to provide the reader with an overview of recent developments in Arterial Spin Labeling (ASL) MRI techniques. A great deal of progress has been made in recent years in terms of the SNR and acquisition speed. New strategies have been introduced to improve labeling efficiency, reduce artefacts, and estimate other relevant physiological parameters besides perfusion. As a result, ASL techniques has become a reliable workhorse for researchers as well as clinicians. After a brief overview of the technique's fundamentals, this article will review new trends and variants in ASL including vascular territory mapping and velocity selective ASL, as well as arterial blood volume imaging techniques...
January 2, 2018: NeuroImage
https://www.readbyqxmd.com/read/29303965/non-invasive-renal-perfusion-imaging-using-arterial-spin-labeling-mri-challenges-and-opportunities
#5
REVIEW
Fabio Nery, Isky Gordon, David L Thomas
Tissue perfusion allows for delivery of oxygen and nutrients to tissues, and in the kidneys is also a key determinant of glomerular filtration. Quantification of regional renal perfusion provides a potential window into renal (patho) physiology. However, non-invasive, practical, and robust methods to measure renal perfusion remain elusive, particularly in the clinic. Arterial spin labeling (ASL), a magnetic resonance imaging (MRI) technique, is arguably the only available method with potential to meet all these needs...
January 5, 2018: Diagnostics
https://www.readbyqxmd.com/read/29302785/dynamic-non-invasive-asl-perfusion-imaging-of-a-normal-pancreas-with-secretin-augmented-mr-imaging
#6
Khoschy Schawkat, Michael Ith, Andreas Christe, Wolfgang Kühn, Yojena Chittazhathu, Lauren Bains, Val Murray Runge, Johannes T Heverhagen
OBJECTIVES: To investigate prospectively the repeatability of pancreatic perfusion measurements using arterial spin labelling (ASL) and to determine the increase in perfusion due to secretin stimulation. MATERIAL AND METHODS: An (FAIR)-TrueFISP ASL sequence was applied to determine the perfusion of the pancreatic head in a 3T MRI scanner. Ten healthy volunteers (four men, six women: mean age 28.5 ± 4.6 years; age range 25-40 years) were investigated twice within 1 week...
January 4, 2018: European Radiology
https://www.readbyqxmd.com/read/29260615/preliminary-evidence-for-cerebral-capillary-shunting-in-adults-with-sickle-cell-anemia
#7
Meher R Juttukonda, Manus J Donahue, Larry T Davis, Melissa C Gindville, Chelsea A Lee, Niral J Patel, Adetola A Kassim, Sumit Pruthi, Jeroen Hendrikse, Lori C Jordan
Elevated flow velocities in adults with sickle cell anemia (SCA) may cause rapid erythrocyte transit through capillaries. This phenomenon could present as dural venous sinus hyperintensity on arterial spin labeling (ASL)-MRI and could be indicative of capillary shunting. Here, the prevalence of ASL venous hyperintensities and association with relevant physiology in adults with SCA was investigated. SCA ( n = 46) and age-matched control ( n = 16) volunteers were recruited for 3.0 T MRI. Pseudo-continuous ASL-MRI was acquired for cerebral blood flow (CBF) calculation and venous hyperintensity determination; venous signal intensity and a categorical venous score (three raters; 0 = no hyperintensity, 1 = focal hyperintensity, and 2 = diffuse hyperintensity) were recorded...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/29244086/cerebral-blood-flow-changes-after-radiation-therapy-identifies-pseudo-progression-in-diffuse-intrinsic-pontine-gliomas
#8
Raphael Calmon, Stephanie Puget, Pascale Varlet, Volodia Dangouloff-Ros, Thomas Blauwblomme, Kevin Beccaria, David Grevent, Christian Sainte-Rose, David Castel, Marie-Anne Debily, Christelle Dufour, Stéphanie Bolle, Frederic Dhermain, Ana Saitovitch, Monica Zilbovicius, Francis Brunelle, Jacques Grill, Nathalie Boddaert
Background: The interval between progression and death in diffuse intrinsic pontine glioma (DIPG) is usually < 6 months. However, reports of longer patient survival following radiotherapy, in the presence of radiological signs of progression, suggest that these cases may be comparable to pseudo-progression observed in adult glioblastoma. Our aim was to identify such cases and compare their multimodal MRI features with those of patients that did not present the same evolution. Methods: Multimodal MRI of 43 children treated for DIPG were retrospectively selected at four time points: baseline, after-radiotherapy, during true-progression, and at the last-visit...
December 13, 2017: Neuro-oncology
https://www.readbyqxmd.com/read/29238007/diagnostic-performance-of-arterial-spin-labeling-for-grading-nonenhancing-astrocytic-tumors
#9
Delgerdalai Khashbat, Masafumi Harada, Takashi Abe, Mungunbagana Ganbold, Seiji Iwamoto, Naoto Uyama, Saho Irahara, Youichi Otomi, Teruyoshi Kageji, Shinji Nagahiro
PURPOSE: We evaluated the utility of arterial spin labeling (ASL) imaging of tumor blood flow (TBF) for grading non-enhancing astrocytic tumors. MATERIALS AND METHODS: Thirteen non-enhancing astrocytomas were divided into high-grade (n = 7) and low-grade (n = 6) groups. Both ASL and conventional sequences were acquired using the same magnetic resonance machine. Intratumoral absolute maximum TBF (TBFmax), absolute mean TBF (TBFmean), and corresponding values normalized to cerebral blood flow (TBFmax and TBFmean ratios) were measured...
December 12, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/29229306/pseudo-continuous-arterial-spin-labeling-quantification-in-anemic-subjects-with-hyperemic-cerebral-blood-flow
#10
Adam Bush, Yaqiong Chai, So Young Choi, Lena Vaclavu, Scott Holland, Aart Nederveen, Thomas Coates, John Wood
PURPOSE: To investigate possible sources of quantification errors in global cerebral blood flow (CBF) measurements by comparing pseudo continuous arterial spin labeling (PCASL) and phase contrast (PC) MRI in anemic, hyperemic subjects. METHODS: All studies were performed on a Philips 3T Achieva MRI scanner. PC and PCASL CBF examinations were performed in 10 healthy, young adult subjects and 18 young adults with chronic anemia syndromes including sickle cell disease and thalassemia...
December 8, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29214340/management-and-outcomes-of-treating-pediatric-medulloblastoma-an-eight-years-experience-in-an-iranian-pediatric-center
#11
Azim Mehrvar, Maryam Tashvighi, Amir Abbas Hedayati Asl, Naghmeh Niktoreh-Mofrad, Narjes Mehrvar, Negar Afsar, Ali Naderi, Mardawig Allebouyeh, Ibrahim Qaddoumi, Mohammad Faranoush
PURPOSE: The clinical management of pediatric medulloblastoma requires a multidisciplinary approach, which can be challenging, especially in low- and middle-income countries. The aim of this study was to identify current challenges and describe the treatment and outcomes of Iranian pediatric patients with medulloblastoma who were referred to our center in Tehran, Iran. METHODS: Our retrospective review included 126 patient records from April 2007 to May 2015. The records were analyzed for epidemiologic features, treatment modalities, overall survival, and progression-free survival...
December 6, 2017: Child's Nervous System: ChNS: Official Journal of the International Society for Pediatric Neurosurgery
https://www.readbyqxmd.com/read/29205641/clinical-and-arterial-spin-labeling-brain-mri-features-of-transitional-venous-anomalies
#12
Michael Zhang, Nicholas A Telischak, Nancy J Fischbein, Gary K Steinberg, Michael Marks, Greg Zaharchuk, Jeremy J Heit, Michael Iv
BACKGROUND AND PURPOSE: Transitional venous anomalies (TVAs) are rare cerebrovascular lesions that resemble developmental venous anomalies (DVAs), but demonstrate early arteriovenous shunting on digital subtraction angiography (DSA) without the parenchymal nidus of arteriovenous malformations (AVMs). We investigate whether arterial spin labeling (ASL) magnetic resonance imaging (MRI) can distinguish brain TVAs from DVAs and guide their clinical management. METHODS: We conducted a single-center retrospective review of patients with brain parenchymal DVA-like lesions with increased ASL signal on MRI...
December 4, 2017: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
https://www.readbyqxmd.com/read/29196191/arterial-spin-labeling-perfusion-mri-signal-denoising-using-robust-principal-component-analysis
#13
Hancan Zhu, Jian Zhang, Ze Wang
BACKGROUND: Arterial spin labeling (ASL) perfusion MRI provides a non-invasive way to quantify regional cerebral blood flow (CBF) and has been increasingly used to characterize brain state changes due to disease or functional alterations. Its use in dynamic brain activity study, however, is still hampered by the relatively low signal-to-noise-ratio (SNR) of ASL data. NEW METHOD: The aim of this study was to validate a new temporal denoising strategy for ASL MRI...
November 28, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/29176470/quantitative-methods-in-abdominal-mri-perfusion-imaging
#14
Ananth J Madhuranthakam, Qing Yuan, Ivan Pedrosa
Recent improvements in arterial spin labeled (ASL) and vastly undersampled dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) acquisitions are providing a new opportunity to explore the routine use of quantitative perfusion imaging for evaluation of a variety of abdominal diseases in clinical practice. In this review, we discuss different approaches for the acquisition and data analysis of ASL and DCE MRI techniques for quantification of tissue perfusion and present various clinical applications of these techniques in both neoplastic and non-neoplastic conditions in the abdomen...
December 2017: Topics in Magnetic Resonance Imaging: TMRI
https://www.readbyqxmd.com/read/29168667/arterial-spin-labeling-for-the-measurement-of-cerebral-perfusion-and-angiography
#15
Peter Jezzard, Michael A Chappell, Thomas W Okell
Arterial spin labeling (ASL) is an MRI technique that was first proposed a quarter of a century ago. It offers the prospect of non-invasive quantitative measurement of cerebral perfusion, making it potentially very useful for research and clinical studies, particularly where multiple longitudinal measurements are required. However, it has suffered from a number of challenges, including a relatively low signal-to-noise ratio, and a confusing number of sequence variants, thus hindering its clinical uptake. Recently, however, there has been a consensus adoption of an accepted acquisition and analysis framework for ASL, and thus a better penetration onto clinical MRI scanners...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/29160952/transit-time-mapping-in-the-mouse-brain-using-time-encoded-pcasl
#16
Lydiane Hirschler, Leon P Munting, Artem Khmelinskii, Wouter M Teeuwisse, Ernst Suidgeest, Jan M Warnking, Louise van der Weerd, Emmanuel L Barbier, Matthias J P van Osch
The cerebral blood flow (CBF) is a potential biomarker for neurological disease. However, the arterial transit time (ATT) of the labeled blood is known to potentially affect CBF quantification. Furthermore, ATT could be an interesting biomarker in itself, as it may reflect underlying macro- and microvascular pathologies. Currently, no optimized magnetic resonance imaging (MRI) sequence exists to measure ATT in mice. Recently, time-encoded labeling schemes have been implemented in rats and humans, enabling ATT mapping with higher signal-to-noise ratio (SNR) and shorter scan time than multi-delay arterial spin labeling (ASL)...
November 21, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/29159053/using-simultaneous-pet-mri-to-compare-the-accuracy-of-diagnosing-frontotemporal-dementia-by-arterial-spin-labelling-mri-and-fdg-pet
#17
Udunna C Anazodo, Elizabeth Finger, Benjamin Yin Ming Kwan, William Pavlosky, James Claude Warrington, Matthias Günther, Frank S Prato, Jonathan D Thiessen, Keith S St Lawrence
Purpose: The clinical utility of FDG-PET in diagnosing frontotemporal dementia (FTD) has been well demonstrated over the past decades. On the contrary, the diagnostic value of arterial spin labelling (ASL) MRI - a relatively new technique - in clinical diagnosis of FTD has yet to be confirmed. Using simultaneous PET/MRI, we evaluated the diagnostic performance of ASL in identifying pathological abnormalities in FTD (FTD) to determine whether ASL can provide similar diagnostic value as FDG-PET...
2018: NeuroImage: Clinical
https://www.readbyqxmd.com/read/29153364/application-of-arterial-spin-labeling-perfusion-mri-to-differentiate-benign-from-malignant-intracranial-meningiomas
#18
Xin J Qiao, Hyun Grace Kim, Danny J J Wang, Noriko Salamon, Michael Linetsky, Ali Sepahdari, Benjamin M Ellingson, Whitney B Pope
PURPOSE: Differentiating WHO grade I-III of meningioma by non-invasive imaging is challenging. This study investigated the potential of MR arterial spin labeling (ASL) to establish tumor grade in meningioma patients. MATERIAL AND METHODS: Pseudo-continuous ASL with 3D background suppressed gradient and spin echo (GRASE) was acquired on 54 patients with newly diagnosed or recurrent intracranial meningioma. Perfusion patterns characterized in CBF color maps were independently evaluated by three neuroradiologists blinded to patient history, and correlated with tumor grade from histo-pathological review...
December 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/29135072/measuring-human-placental-blood-flow-with-multidelay-3d-grase-pseudocontinuous-arterial-spin-labeling-at-3t
#19
Xingfeng Shao, Dapeng Liu, Thomas Martin, Teresa Chanlaw, Sherin U Devaskar, Carla Janzen, Aisling M Murphy, Daniel Margolis, Kyunghyun Sung, Danny J J Wang
BACKGROUND: Placenta influences the health of both a woman and her fetus during pregnancy. Maternal blood supply to placenta can be measured noninvasively using arterial spin labeling (ASL). PURPOSE: To present a multidelay pseudocontinuous arterial spin labeling (pCASL) combined with a fast 3D inner-volume gradient- and spin-echo (GRASE) imaging technique to simultaneously measure placental blood flow (PBF) and arterial transit time (ATT), and to study PBF and ATT evolution with gestational age during the second trimester...
November 14, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29134725/reproducibility-of-brain-mri-segmentation-algorithms-empirical-comparison-of-local-map-pstaple-freesurfer-and-fsl-first
#20
Clemente Velasco-Annis, Alireza Akhondi-Asl, Aymeric Stamm, Simon K Warfield
BACKGROUND AND PURPOSE: Segmentation of human brain structures is crucial for the volumetric quantification of brain disease. Advances in algorithmic approaches have led to automated techniques that save time compared to interactive methods. Recently, the utility and accuracy of template library fusion algorithms, such as Local MAP PSTAPLE (PSTAPLE), have been demonstrated but there is little guidance regarding its reproducibility compared to single template-based algorithms such as FreeSurfer and FSL-FIRST...
November 14, 2017: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
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