MRI perfusion brain

Structural MRI (sMRI)-identified tissue "growth" after neuropsychological training has been reported in many studies but the origins of those apparent tissue changes (ATC) still remain elusive. One possible contributor to ATC is brain perfusion since T1-weighted MRI, the tool used to identify ATC, is sensitive to perfusion-change induced tissue T1 alterations. To test the hypothetical perfusion contribution to ATC, sMRI data were acquired before and after short-term global and regional perfusion manipulations via intaking a 200 mg caffeine pill and performing a sensorimotor task...

Global synchronization across specialized brain networks is a common feature of network models and in-vivo electrical measurements. Although the imaging of specialized brain networks with blood oxygenation sensitive resting state functional magnetic resonance imaging (rsfMRI) has enabled detailed study of regional networks, the study of globally correlated fluctuations with rsfMRI is confounded by spurious contributions to the global signal from systemic physiologic factors and other noise sources. Here we use an alternative rsfMRI method, arterial spin labeled perfusion MRI, to characterize global correlations and their relationship to correlations and anti-correlations between regional networks...

Background Cerebral white matter hyperintensities (WMHs), lacunes, and microbleeds are seen on magnetic resonance imaging (MRI) in small vessel disease (SVD). Purpose To assess SVD on MRI and its evolution over five years in an elderly population and to investigate whether relative cerebral blood flow (rCBF) at baseline was related to the progression of white matter (WM) lesions. Material and Methods In a population-based study, 406 participants aged 75 years underwent morphological MRI of the brain and 252 of them again at age 80 years...

Hypoxia plays an important role for the prognosis and therapy response of cancer. Thus, hypoxia imaging would be a valuable tool for pre-therapeutic assessment of tumor malignancy. However, there is no standard validated technique for clinical application available yet. Therefore, we performed a study in 12 patients with high-grade glioma, where we directly compared the two currently most promising techniques, namely the MR-based relative oxygen extraction fraction (MR-rOEF) and the PET hypoxia marker H-1-(3-[(18) F]-fluoro-2-hydroxypropyl)-2-nitroimidazole ([(18) F]-FMISO)...

INTRODUCTION: Increased intracranial pressure (ICP) is a significant neurological issue that may lead to permanent neurological sequelae. When evaluating patients with traumatic brain injury, it is crucial to identify those with high ICP in order to expedite ICP lowering measures and maintain adequate cerebral perfusion. Several measures are used to recognise patients with increased ICP including CT scan, MRI, ICP monitor, and lumbar puncture (LP). However, these tests can be invasive, associated with radiation exposure, contraindicated, or not readily available...

Neuroimaging plays a significant role in the diagnosis of intracranial tumours, especially brain gliomas, and must consist of an assessment of location and extent of the tumour and of its biological activity. Therefore, morphological imaging modalities and functional, metabolic or molecular imaging modalities should be combined for primary diagnosis and for following the course and evaluating therapeutic effects. Magnetic resonance imaging (MRI) is the gold standard for providing detailed morphological information and can supply some additional insights into metabolism (MR spectroscopy) and perfusion (perfusion-weighted imaging) but still has limitations in identifying tumour grade, invasive growth into neighbouring tissue and treatment-induced changes, as well as recurrences...

PURPOSE: To assess whether relative cerebral blood volume (rCBV) can provide information to reliably evaluate the stages of late delayed radiation-induced brain injury. MATERIALS AND METHODS: Forty patients diagnosed with late delayed radiation-induced brain injury were enrolled. The patients were examined using a 1.5T magnetic resonance imaging (MRI) system equipped with an 8-channel head coil. An echo planar imaging (EPI) sequence was used in perfusion-weighted imaging (PWI)...

Several studies show that itch and scratching cannot only be induced by pruritogens like histamine or cowhage, but also by the presentation of certain (audio-) visual stimuli like pictures on crawling insects or videos showing other people scratching. This phenomenon is coined "Contagious itch" (CI). Due to the fact that CI is more profound in patients with the chronic itchy skin disease atopic dermatitis (AD), we believe that it is highly relevant to study brain processing of CI in this group. Knowledge on brain areas involved in CI in AD-patients can provide us with useful hints regarding non-invasive treatments that AD-patients could profit from when they are confronted with itch-inducing situations in daily life...

Detection of subtle ischemic injuries in moyamoya disease may enable optimization of timing of revascularization surgery, and could potentially improve functional outcomes. Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to study functional organization of the brain, but it remains unclear whether rs-fMRI could elucidate distinct characteristics in moyamoya disease. Here, we aimed to determine changes in a conventional rs-fMRI measure and analyze any associations with clinical symptoms and cerebral hemodynamics...

Vascular endothelial growth factor A (VEGF-A) is considered one of the most important factors in tumor angiogenesis, and consequently, a number of therapeutics have been developed to inhibit VEGF signaling. Therapeutic strategies to target brain malignancies, both primary brain tumors, particularly in pediatric patients, and metastases, are lacking, but targeting angiogenesis may be a promising approach. Multiparametric MRI was used to investigate the response of orthotopic SF188(luc) pediatric glioblastoma xenografts to small molecule pan-VEGFR inhibitor cediranib and the effects of both cediranib and cross-reactive human/mouse anti-VEGF-A antibody B20-4...

BACKGROUND: The imaging method most frequently employed to identify brain areas involved in neuronal processing of nociception and brain pain perception is blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI). Arterial spin labelling (ASL), in contrast, offers advantages when slow varying changes in brain function are investigated. Chronic pelvic pain syndrome (CPPS) is a disorder of, mostly, young males that leads to altered pain perceptions in structures related to the pelvis...

OBJECTIVE: To systematically review brain imaging studies in myotonic dystrophy type 1 (DM1). METHODS: We searched Embase (index period 1974-2016) and MEDLINE (index period 1946-2016) for studies in patients with DM1 using MRI, magnetic resonance spectroscopy (MRS), functional MRI (fMRI), CT, ultrasound, PET, or SPECT. From 81 studies, we extracted clinical characteristics, primary outcomes, clinical-genetic correlations, and information on potential risk of bias...

INTRODUCTION: In the last 20 years growing attention has been devoted to multimodal imaging. The recent literature is rich of clinical and research studies that have been performed using different imaging modalities on both separate and integrated Positron Emission Tomography (PET) and Magnetic Resonance (MR) scanners. However, today, hybrid PET/MR systems measure signals related to brain structure, metabolism, neurochemistry, perfusion, and neuronal activity simultaneously, i.e. in the same physiological conditions...

Objective A child presenting with a first attack of migraine with aura usually undergoes magnetic resonance imaging (MRI) to rule out stroke. The purpose of this study was to report vascular and brain perfusion findings in children suffering from migraine with aura on time-of-flight MR angiography (TOF-MRA) and MR perfusion imaging using arterial spin labelling (ASL). Methods We retrospectively included all children who had undergone an emergency MRI examination with ASL and TOF-MRA sequences for acute neurological deficit and were given a final diagnosis of migraine with aura...

Rapid revascularization is highly effective for acute stroke, but animal studies suggest that reperfusion edema may attenuate its beneficial effects. We investigated the relationship between reperfusion and edema in patients from the Echoplanar Imaging Thrombolysis Evaluation Trial (EPITHET) and Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE) cohorts. Reperfusion percentage was measured as the difference in perfusion-weighted imaging lesion volume between baseline and follow-up (day 3-5 for EPITHET; day 6-8 for MR RESCUE)...

BACKGROUND AND PURPOSE: Blood-brain barrier (BBB) disruption detected on magnetic resonance imaging (MRI) in acute ischemic stroke as a hyperintense acute reperfusion marker (HARM) is associated with upregulation of matrix metalloproteinase-9 (MMP-9). Although activated leukocytes, including monocytes, are the main source of MMPs, limited data exist to support relationship between leukocyte activation and BBB disruption in patients with acute ischemic stroke. The goal of this study is to investigate the relationship between neutrophils, lymphocytes, and monocytes with BBB disruption detected as HARM (+) in patients with acute ischemic stroke...

Children who present with acute transient focal neurologic symptoms raise concern for stroke or transient ischemic attack. We present a series of 16 children who presented with transient focal neurologic symptoms that raised concern for acute stroke but who had no evidence of infarction and had unilateral, potentially reversible imaging features on vascular and perfusion-sensitive brain MR imaging. Patients were examined with routine brain MR imaging, MRA, perfusion-sensitive sequences, and DWI. Fourteen (88%) children had lateralized MRA evidence of arterial tree pruning without occlusion, all had negative DWI findings, and all showed evidence of hemispheric hypoperfusion by susceptibility-weighted imaging or arterial spin-labeling perfusion imaging at presentation...

BACKGROUND: Studies of brain perfusion during migraine without aura attacks have inconsistent results. METHODS: Arterial spin labeling MRI, a non-invasive quantitative perfusion technique, was used to prospectively study a spontaneous untreated migraine without aura attack and a headache-free period. Image analysis used FSL and MATLAB software; Group analysis used permutation methods for perfusion differences between sessions. RESULTS: Thirteen women (age 35...

BACKGROUND: Penumbra salvage from infarction by early reperfusion within the time window is the target of acute ischemic stroke therapies. Although the penumbral imaging is potently usable in clinic trial, additional work needs to be performed to advancing the field with better-defined, evaluated, and validated imaging measures. METHODS: Mice were subjected to permanent stroke by right middle cerebral artery (MCA) occlusion. Multimodel magnetic resonance imaging (MRI) method was assessed to define the penumbra as that brain region in which the perfusion and diffusion-weighted MR images are mismatched (perfusion-weighted imaging [PWI]-diffusion-weighted imaging [DWI] mismatch)...

PURPOSE: Despite the excellent capacity of the conventional MRI to image brain tumours, problems remain in answering a number of critical diagnostic questions. To overcome these diagnostic shortcomings, PET using radiolabeled amino acids and perfusion-weighted imaging (PWI) are currently under clinical evaluation. The role of amino acid PET and PWI in different diagnostic challenges in brain tumours is controversial. METHODS: Based on the literature and experience of our centres in correlative imaging with PWI and PET using O-(2-[(18)F]fluoroethyl)-l-tyrosine or 3,4-dihydroxy-6-[(18)F]-fluoro-l-phenylalanine, the current role and shortcomings of amino acid PET and PWI in different diagnostic challenges in brain tumours are reviewed...