Search results for " MR"
showing 10 items of 495 documents
VBM-DTI correlates of verbal intelligence: a potential link to Broca's area.
2012
Abstract Human brain lesion studies first investigated the biological roots of cognitive functions including language in the late 1800s. Neuroimaging studies have reported correlation findings with general intelligence predominantly in fronto-parietal cortical areas. However, there is still little evidence about the relationship between verbal intelligence and structural properties of the brain. We predicted that verbal performance is related to language regions of Broca's and Wernicke's areas. Verbal intelligence quotient (vIQ) was assessed in 30 healthy young subjects. T1-weighted MRI and diffusion tensor imaging data sets were acquired. Voxel-wise regression analyses were used to correla…
Resovist enhanced MR imaging of the liver: Does quantitative assessment help in focal lesion classification and characterization?
2009
Purpose: To improve characterization of focal liver lesions by a prospective quantitative analysis of percentage signal intensity change, in dynamic and late phases after slow (0.5 mL/s) Resovist administration. Materials and Methods: Seventy-three patients were submitted on clinical indication to MR examination with Resovist. Signal intensity of 92 detected focal lesions (5–80 mm) were measured with regions of interest and normalized to paravertebral muscle in arterial, portal, equilibrium and T1/T2 late phases, by two observers in conference. Five values of percentage variations per patient were obtained and statistically evaluated. Results: The enhancement obtained on dynamic study is mo…
Diagnostic performance of gadobenate dimeglumine enhanced MR angiography of the iliofemoral and calf arteries: a large-scale multicenter trial
2007
OBJECTIVE. The purpose of this study was to compare gadobenate dimeglumine–enhanced MR angiography and unenhanced time-of-flight MR angiography for the detection of significant peripheral arterial occlusive disease using digital subtraction angiography as our reference standard. SUBJECTS AND METHODS. Two hundred seventy-two patients underwent MR angiography and digital subtraction angiography of the iliofemoral arteries. MR angiography was performed before (2D time-of-flight acquisitions) and after (spoiled gradient-echo acquisitions) the administration of 0.1 mmol/kg of gadobenate dimeglumine at 1–2 mL/s. Contrast-enhanced MR angiography and digital subtraction angiography of the calf arte…
Study of hypothalamic metabolism in cluster headache by proton MR spectroscopy
2006
The authors used 1H-MRS to investigate hypothalamic metabolism in 26 patients with cluster headache (CH) and 12 healthy subjects. Hypothalamic N-acetylaspartate/creatine was reduced in patients with CH vs controls (p < 0.01). Dividing the patients into episodic CH outside- and in-cluster periods and chronic CH, the hypothalamic N-acetylaspartate/creatine in all three subgroups of patients was reduced. The reduction of the neuronal marker N-acetylaspartate is consistent with hypothalamic neuronal dysfunction in patients with CH.
Frontoparietal cortex and cerebellum contribution to the update of actual and mental motor performance during the day
2016
AbstractActual and imagined movement speed increases from early morning until mid-afternoon. Here, we investigated the neural correlates of these daily changes. Fifteen subjects performed actual and imagined right finger opposition movement sequences at 8 am and 2 pm. Both actual and imagined movements were significantly faster at 2 pm than 8 am. In the morning, actual movements significantly activated the left primary somatosensory and motor areas, and bilaterally the cerebellum; in the afternoon activations were similar but reduced. Contrast analysis revealed greater activity in the cerebellum, the left primary sensorimotor cortex and parietal lobe in the morning than in the afternoon. Im…
Advanced magnetic resonance imaging of cortical laminar necrosis in patients with stroke
2019
Purpose The aim of this study was to assess the novel advanced magnetic resonance imaging findings of acute stage cortical laminar necrosis developing after complicated cardiovascular or abdominal surgery. Materials and methods This institutional review board-approved study included patients with postoperative stroke due to cortical laminar necrosis imaged with magnetic resonance in the acute stage. Brain magnetic resonance imaging examinations were obtained on a 3T magnetic resonance scanner within 48 hours of the neurological symptoms, including diffusion-weighted images (b value, 1000 s/mm2) and arterial spin labelling using a pseudo-continuous arterial spin labelling method in four pati…
Disturbed structural connectivity is related to inattention and impulsivity in adult attention deficit hyperactivity disorder
2010
Inattention and impulsivity are the most prominent clinical features of attention deficit hyperactivity disorder (ADHD) in adulthood. Structural and functional neuroimaging studies of subjects with ADHD have demonstrated abnormalities in several brain areas, including fronto-striatal and fronto-cerebellar networks. Mostly, these studies were based on volumetric measurements and have been conducted in children. We investigated white matter (WM) integrity and correlation with measures of attention and impulsivity in adult patients with ADHD adopting diffusion tensor imaging (DTI). N = 37 (21 males) never-medicated adult patients with ADHD combined subtype and N = 34 (16 males) healthy control…
Corpus callosum involvement: a useful clue for differentiating Fabry Disease from Multiple Sclerosis.
2017
PURPOSE: Multiple sclerosis (MS) has been proposed as a possible differential diagnosis for Fabry disease (FD). The aim of this work was to evaluate the involvement of corpus callosum (CC) on MR images and its possible role as a radiological sign to differentiate between FD and MS. METHODS: In this multicentric study, we retrospectively evaluated the presence of white matter lesions (WMLs) on the FLAIR images of 104 patients with FD and 117 patients with MS. The incidence of CC-WML was assessed in the two groups and also in a subgroup of 37 FD patients showing neurological symptoms. RESULTS: WMLs were detected in 50 of 104 FD patients (48.1%) and in all MS patients. However, a lesion in the…
Plantar fascia evaluation with a dedicated magnetic resonance scanner in weight-bearing position: our experience in patients with plantar fasciitis a…
2010
Purpose. This study assessed the usefulness of upright weight-bearing examination of the ankle/hind foot performed with a dedicated magnetic resonance (MR)imaging scanner in the evaluation of the plantar fascia in healthy volunteers and in patients with clinical evidence of plantar fasciitis. Materials and methods. Between January and March 2009, 20 patients with clinical evidence of plantar fasciitis (group A) and a similar number of healthy volunteers (group B) underwent MR imaging of the ankle/hind foot in the upright weight-bearing and conventional supine position. A 0.25-Tesla MR scanner (G-Scan, Esaote SpA, Genoa, Italy) was used with a dedicated receiving coil for the ankle/hind foot…
Standardized T2* map of normal human heart in vivo to correct T2* segmental artefacts.
2007
A segmental, multislice, multi-echo T2* MRI approach could be useful in heart iron-overloaded patients to account for heterogeneous iron distribution, demonstrated by histological studies. However, segmental T2* assessment in heart can be affected by the presence of geometrical and susceptibility artefacts, which can act on different segments in different ways. The aim of this study was to assess T2* value distribution in the left ventricle and to develop a correction procedure to compensate for artefactual variations in segmental analysis. MRI was performed in four groups of 22 subjects each: healthy subjects (I), controls (II) (thalassemia intermedia patients without iron overload), thala…