MRI perfusion brain

BACKGROUND: Due to the low signal-to-noise-ratio (SNR) and unavoidable head motions, the pairwise subtraction perfusion signal extraction process in arterial spin labeling (ASL) perfusion MRI can produce extreme outliers. COMPARISON WITH EXISTING METHODS: We previously proposed an adaptive outlier cleaning (AOC) algorithm for ASL MRI. While it performed well even for clinical ASL data, two issues still exist. One is that if the reference is already dominated by noise, outlier cleaning using low correlation with the mean as a rejection criterion will actually reject the less noisy samples but keep the more noisy ones...

Objective - to assess how rCBV maps correlate with irradiation treatment plans in patients with recurrent tumor in order to identify potential differences and optimize treatment planning. 11 patients with brain HGG have taken participation in this study. Study was conducted in Radiation Medicine Center and Scientific Research Institute of Clinical Medicine. All patients underwent DSC-MRI and routine MRI imaging prior to re-irradiation treatment planning, and underwent treatment as per routine clinical protocol...

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Background and Aims: Vascular border zones and the gray-white matter junction are preferred sites for the development of brain metastases (BM), whereas microvascular lesions are known to be a protective factor. In this proof of concept study, we aim to study the relationship of blood perfusion and the spatial distribution of BM. Materials and Methods: An average CT perfusion atlas of 107 healthy patients was created. Voxel-wise reference perfusion values were extracted from BM-negative and BM-positive regions in a second cohort of 100 untreated patients harboring 809 BM confirmed by MRI...

Biomarkers have the potential to aid in the study of Alzheimer’s disease (AD); unfortunately, AD biomarker values often have a high degree of overlap between healthy and AD individuals. This study investigates the potential utility of a series of novel AD biomarkers, the sixty second 129 Xe retention time, and the xenon washout parameter, based on the washout of hyperpolarized 129 Xe from the brain of AD participants following inhalation. The xenon washout parameter is influenced by cerebral perfusion, T1 relaxation of xenon, and the xenon partition coefficient, all factors influenced by AD...

Objective: To characterize the patterns of brain atrophy and perfusion as measured by arterial spin labeling (ASL)-MRI, in amyotrophic lateral sclerosis (ALS) patients with varying levels of cognitive deficit, including ALS with frontotemporal dementia (FTD). Methods: A total of 55 ALS patients and 20 healthy controls (HCs) were included, and all participants underwent neuropsychological assessments and MRI scans. According to their cognitive performance, ALS patients were further subclassified into ALS with normal cognition (ALS-Cn, n  = 27), ALS with cognitive impairment (ALS-Ci, n  = 17), and ALS-FTD ( n  = 11)...

OBJECTIVE: This study aimed to assess the cognitive functions and cerebral blood flow measured with arterial spin labeling (ASL) and their possible correlations with vascular age in untreated middle-aged patients with grade 1-2 essential arterial hypertension (EAH). METHODS: We examined 73 subjects aged 40-59 years (33 with EAH and 40 healthy volunteers [controls]). Neuropsychological assessment included Montreal Cognitive Assessment (MoCA), Trail Making test (part A and part B), Stroop Color and Word Test, verbal fluency test (phonemic verbal fluency and semantic verbal fluency), 10‑item word list learning task...

PURPOSE: The purposes of this study are to study the impact of deep brain involvement on overall survival (OS) and progression-free survival (PFS) in intracranial primary CNS lymphoma (PCNSL), and to explore possible mechanisms for this impact using advanced MRI techniques. METHODS: Seventy-nine patients with histologically verified PCNSL were identified from a prospective clinical database of patients treated at Oslo University Hospital between 2003 and 2014. Patients were treated per standard chemotherapeutic regimens (N = 57) or no chemotherapy (N = 22)...

OBJECTIVE: MRI and CT scans are usually normal in mild traumatic brain injury (mTBI) although 15-20% of such patients suffer for months from fatigue, headache, anxiety, sleep and other disorders. mTBI is suspected to be a cerebrovascular injury, similar to moderate and severe TBI. Brain SPECT is more sensitive and shows perfusion abnormalities immediately after mTBI. This work explores the perfusion abnormalities for young patients suffering from fatigue several months after mTBI. PATIENTS AND METHODS: Twelve mTBI patients (age:8-36 yr, 4 male) with no history of fatigue prior to trauma were prospectively studied following onset of fatigue 6-12 months after mTBI utilizing 99 m-Tc ECD brain SPECT with early and delayed radiotracer imaging...

PURPOSE: Gadobutrol is a gadolinium-based contrast material (GBCM) with a high concentration of gadolinium and high relaxivity. Our purpose was to evaluate the signal intensity profiles in brain tissue for the bolus width and degree of signal change after bolus injection using an echo planar dynamic susceptibility contrast (DSC) sequence. We compared gadobutrol to gadoteridol using various injection speeds and saline flush volumes. METHODS: We studied 97 patients who underwent brain MRI...

BACKGROUND AND PURPOSE: Standard assessment criteria for brain tumors that only include anatomic imaging continue to be insufficient. While numerous studies have demonstrated the value of DSC-MR imaging perfusion metrics for this purpose, they have not been incorporated due to a lack of confidence in the consistency of DSC-MR imaging metrics across sites and platforms. This study addresses this limitation with a comparison of multisite/multiplatform analyses of shared DSC-MR imaging datasets of patients with brain tumors...

INTRODUCTION: Cerebral complications are the main reasons for morbidity and mortality in preeclampsia and eclampsia. As yet, we do not know whether the pathophysiology entails hypo- or hyperperfusion of the brain, or how and when edema emerges, due to the difficulty of examining the cerebral circulation. MATERIAL AND METHODS: We have used a non-invasive diffusion weighted-magnetic resonance imaging technique, intravoxel incoherent motion, to study cerebral perfusion on the capillary level and cerebral edema in women with preeclampsia (n = 30), normal pregnancy (n = 32), and non-pregnant women (n = 16)...

Distinguishing relapsing-remitting multiple sclerosis (RRMS) and neuromyelitis optica (NMO) is clinically important because they differ in prognosis and treatment. This study aimed to identify perfusion abnormalities in RRMS and NMO and their correlations with gray matter volume (GMV) atrophy and clinical parameters. Structural and arterial spin labeling MRI scans were performed in 39 RRMS patients, 62 NMO patients, and 73 healthy controls. The gray matter cerebral blood flow (CBF) values were voxel-wisely compared among the three groups with and without GMV correction...

BACKGROUND: Arterial spin labeling (ASL) is an established magnetic resonance imaging (MRI) technique that is finding broader applications in functional studies of the healthy and diseased brain. To promote improvement in cerebral blood flow (CBF) signal specificity, many algorithms and imaging procedures, such as subtraction methods, were proposed to eliminate or, at least, minimize noise sources. Therefore, this study addressed the main considerations of how CBF functional connectivity (FC) is changed, regarding resting brain network (RBN) identification and correlations between regions of interest (ROI), by different subtraction methods and removal of residual motion artifacts and global signal fluctuations (RMAGSF)...

OBJECTIVE: Crossed aphasia (CA), usually referred to as an acquired language disturbance, is caused by a lesion in the cerebral hemisphere ipsilateral to the dominant hand, and the exact mechanism is not clear. The development of handedness is influenced by education and training and the impact of habitualization, while language is more susceptible to the impact of speech habits, and it is not absolutely accurate to judge cerebral language dominance by the degree of hand preference. METHODS: We describe a case of CA after right hemispheric stroke in a right-handed patient with atypical language dominance and attempt to analyze the mechanism of CA based on functional imaging methods, including arterial spin labeling (ASL) and positron emission tomography/magnetic resonance imaging (PET-MRI)...

OBJECTIVE: We aimed to describe and compare baseline cerebral blood flow (CBF) and microstructural characteristics of normal-appearing white matter (NAWM) within the vulnerable periventricular white matter hyperintensity (PVWMH) penumbra region in predicting white matter hyperintensity (WMH) growth over time. METHODS: Fifty-two patients, aged 82.8 years, underwent serial brain MRI, including pulsed arterial spin labeling and diffusion tensor imaging (DTI). New WMH and persistent NAWM voxels in relation to WMH penumbra at follow-up were identified...

Hyperpolarized (HP) magnetic resonance imaging using [1-13C] pyruvate is a novel method that can characterize energy metabolism in the human brain and brain tumors. Here we present the first dynamically acquired human brain HP 13C metabolic spectra and spatial metabolite maps in cases of both untreated and recurrent tumors. In vivo production of HP lactate from HP pyruvate by tumors was indicative of altered cancer metabolism, while production of HP lactate in the entire brain was likely due to baseline metabolism...

OBJECTIVE: To investigate and describe the distribution of aortic and cerebral blood flow (CBF) in patients with severe valvular aortic stenosis (AS) before and after aortic valve bypass (AVB) surgery. METHODS: We enrolled 10 consecutive patients who underwent AVB surgery for severe AS. Cardiovascular magnetic resonance imaging (CMR) and brain magnetic resonance imaging were performed as baseline before surgery and twice after surgery. Quantitative flow measurements were obtained using 1...

RATIONALE AND OBJECTIVES: The purpose of this study was to correlate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters with data from a specific marker of hypoxia, hypoxia-inducible factor 1α (HIF-1α), in human gliomas on a point-to-point basis by using coregistered magnetic resonance imaging and frameless stereotactic biopsies. MATERIALS AND METHODS: Thirty-four patients with treatment-naive gliomas underwent DCE, axial T1-weighted, T2-weighted, T2-weighted fluid acquisition of inversion recovery, and three-dimensional T1-weighted brain volume with gadolinium contrast enhancement sequences on a 3...

Parkinson's disease (PD) is an age-related neurodegenerative disease that produces changes in movement, cognition, sleep, and autonomic function. Motor learning involves acquisition of new motor skills through practice, and is affected by PD. The purpose of the present study was to evaluate regional differences in resting cerebral blood flow (rCBF), measured using arterial spin labeling (ASL) MRI, during a finger-typing task of motor skill acquisition in PD patients compared to age- and gender-matched controls...