T2* measurements in human brain at 1.5, 3 and 7 T

Peters, Andrew M.; Brookes, Matthew J.; Hoogenraad, F.; Gowland, Penny A.; Francis, Susan T.; Morris, Peter G.; Bowtell, Richard

doi:10.1016/j.mri.2007.02.014

Cited by 217 publications

(217 citation statements)

References 14 publications

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“…Although the same resolution may be obtained in whole-brain data through parallel imaging, the use of a transmit-receive surface coil eliminates the need for parallel imaging and thus the risk of associated artifacts ( 21 ). Despite the long acquisition time used in the current protocol (30 msec, which is on the order of magnitude of cortical gray matter T2* at 7 T [ 22] ), the effective resolution in the readout direction will be affected by only 4% ( 23 ). Although respiration-related artifacts cribed in part to the sensitivity of the surface radiofrequency coil-it was low in distal regions of increased fl ow or…”

Section: Technical Developments: In Vivo Visualization Of Cerebellar mentioning

confidence: 99%

Cerebellar Cortical Layers: In Vivo Visualization with Structural High-Field-Strength MR Imaging

Marques¹,

Zwaag²,

Granziera³

et al. 2010

Radiology

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Purpose:To perform in vivo imaging of the cerebellum with an in-plane resolution of 120 mm to observe its cortical granular and molecular layers by taking advantage of the high signal-to-noise ratio and the increased magnetic susceptibility-related contrast available at high magnetic fi eld strength such as 7 T. Materials and Methods:The study was approved by the institutional review board, and all patients provided written consent. Three healthy persons (two men, one woman; mean age, 30 years; age range, 28-31 years) underwent MR imaging with a 7-T system. Gradient-echo images (repetition time msec/echo time msec, 1000/25) of the human cerebellum were acquired with a nominal in-plane resolution of approximately 120 m m and a section thickness of 1 mm. Results:Structures with dimensions as small as 240 m m, such as the granular and molecular layers in the cerebellar cortex, were detected in vivo. The detection of these structures was confi rmed by comparing the contrast obtained on T2*-weighted and phase images with that obtained on images of rat cerebellum acquired at 14 T with 30 m m in-plane resolution. Conclusion:In vivo cerebellar imaging at near-microscopic resolution is feasible at 7 T. Such detailed observation of an anatomic area that can be affected by a number of neurologic and psychiatric diseases, such as stroke, tumors, autism, and schizophrenia, could potentially provide newer markers for diagnosis and follow-up in patients with such pathologic conditions.q RSNA, 2010

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Section: Technical Developments: In Vivo Visualization Of Cerebellar mentioning

confidence: 99%

Cerebellar Cortical Layers: In Vivo Visualization with Structural High-Field-Strength MR Imaging

Marques¹,

Zwaag²,

Granziera³

et al. 2010

Radiology

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“…53 These phenomena lead to signal loss and difficult phase unwrapping problems, especially in cortical areas near the air-tissue susceptibility interfaces. Such artifacts cannot be easily addressed because the flow-compensation gradients, necessary for accurate phase estimation in venous blood, constrain the minimum TE and TE spacing of the acquisition.…”

Section: Physiologic Interpretation Of Findingsmentioning

confidence: 99%

Quantitative Oxygen Extraction Fraction from 7-Tesla MRI Phase: Reproducibility and Application in Multiple Sclerosis

Fan

Govindarajan

Kinkel

et al. 2014

J Cereb Blood Flow Metab

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Quantitative oxygen extraction fraction (OEF) in cortical veins was studied in patients with multiple sclerosis (MS) and healthy subjects via magnetic resonance imaging (MRI) phase images at 7 Tesla (7 T). Flow-compensated, three-dimensional gradient-echo scans were acquired for absolute OEF quantification in 23 patients with MS and 14 age-matched controls. In patients, we collected T2*-weighted images for characterization of white matter, deep gray matter, and cortical lesions, and also assessed cognitive function. Variability of OEF across readers and scan sessions was evaluated in a subset of volunteers. OEF was averaged from 2 to 3 pial veins in the sensorimotor, parietal, and prefrontal cortical regions for each subject (total of~10 vessels). We observed good reproducibility of mean OEF, with intraobserver coefficient of variation (COV) = 2.1%, interobserver COV = 5.2%, and scan-rescan COV = 5.9%. Patients exhibited a 3.4% reduction in cortical OEF relative to controls (P = 0.0025), which was not different across brain regions. Although oxygenation did not relate with measures of structural tissue damage, mean OEF correlated with a global measure of information processing speed. These findings suggest that cortical OEF from 7-T MRI phase is a reproducible metabolic biomarker that may be sensitive to different pathologic processes than structural MRI in patients with MS.

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“…Most experimental works are performed at high field (>3 T) [6,14,15], in order to improve spatial resolution in small animals. With the recent development of 7 T head and whole-body scanners [16,17] clinical USPIO-enhanced MRI studies may also be performed at high field in the future, as some USPIOs, such as ferumoxtran-10, are already approved for use in humans [18,19]. However, to our knowledge, the quantitative effects on MR signals of macrophage internalisation of USPIO or AMNP have never been reported at high fields.…”

Section: Introductionmentioning

confidence: 99%

Quantitative effects of cell internalization of two types of ultrasmall superparamagnetic iron oxide nanoparticles at 4.7 T and 7 T

Brisset

Desestret²,

Marcellino³

et al. 2009

Eur Radiol

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T2* measurements in human brain at 1.5, 3 and 7 T

Cited by 217 publications

References 14 publications

Cerebellar Cortical Layers: In Vivo Visualization with Structural High-Field-Strength MR Imaging

Cerebellar Cortical Layers: In Vivo Visualization with Structural High-Field-Strength MR Imaging

Quantitative Oxygen Extraction Fraction from 7-Tesla MRI Phase: Reproducibility and Application in Multiple Sclerosis

Quantitative effects of cell internalization of two types of ultrasmall superparamagnetic iron oxide nanoparticles at 4.7 T and 7 T

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