A multispectral analysis of brain tissues

Fletcher, Lynn M.; Barsotti, J; Hornak, Joseph P.

doi:10.1002/mrm.1910290507

Cited by 64 publications

(34 citation statements)

References 25 publications

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“…CSF on the other hand, was less heterogeneous. Even so, healthy brain tissues exhibited a narrow range of qMRI properties, agreeing with previous studies on qMRI of the brain (117,129,130).…”

Section: Qmri For Brain Imagingsupporting

confidence: 90%

“…Healthy brain tissue exhibits narrow ranges of T1, T2 and PD values (117,(128)(129)(130), whereas pathological tissue exhibits significantly different tissue characteristics (131). The observed in vivo qMRI tissue properties can be used in a multi-parametric space, where each tissue property represents one dimension.…”

Section: R1-r2-pd Spacementioning

confidence: 99%

“…Instead of directly using the relaxation times to construct such a space, the use of relaxation rates, R1 and R2, allows greater separation of tissue components (117). The observed R1, R2 and PD values can then be used as coordinates in a 3D feature space, the R1-R2-PD space (117,130). Acquisition noise and anatomical variation causes random variations in the measured R1, R2, and PD values which results in tissue clusters with a mean position and finite distribution.…”

Section: R1-r2-pd Spacementioning

confidence: 99%

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Quantitative Magnetic Resonance Imaging of the Brain : Applications for Tissue Segmentation and Multiple Sclerosis

West¹

2014

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Magnetic resonance imaging (MRI) is a sensitive technique for assessing white matter (WM) lesions in multiple sclerosis (MS), but there is a low correlation between MRI findings and clinical disability. Because of this, other pathological changes are of interest, including changes in normal appearing white matter (NAWM) and diffusely abnormal white matter (DAWM). Even so, the mechanisms leading to permanent disability in MS remain unclear. In contrast to conventional MRI, quantitative MRI (qMRI) is aimed at the direct measurement of the physical tissue properties, such as the relaxation times, T1 and T2, as well as the proton density (PD). QMRI is promising for characterising and quantifying changes in MS and for brain tissue segmentation. The present work describes a novel method of qMRI for the human brain (QMAP), and a segmentation method based on this. The developed methods were validated in control subjects and MR phantoms. Furthermore, an application in diseased human brain was demonstrated in MS patients. In all, 50 healthy controls and 35 MS patients were scanned with qMRI in a total of 225 acquisitions. One major finding of this work was that qMRI was able to detect and quantify changes in the MS disease that were not visible using conventional MRI. In particular, it was found that DAWM appears to constitute an intermediate between focal white matter (WM) lesions and NAWM. These changes may be caused by pathological processes that are not entirely attributable to Wallerian degeneration. This study showed that the QMAP method had high accuracy and relatively high precision, within a clinically acceptable time. This work also demonstrated that qMRI could be used for brain tissue segmentation and volume estimation of the whole brain, using pre-defined tissue characteristics. The results showed that brain tissue segmentation had high repeatability, which was somewhat lower when different geometries were acquired or different field strengths used. In particular, small differences were found between 1.5 T and 3.0 T in deep brain structures, the cerebellum and the brain stem. This work leads the way for early clinical applications of qMRI, and the challenge for the years to come is to understand the connection between qMRI properties of the brain and underlying biology.Bildtagning med magnetresonanstomografi (MRT) är en teknik som kan användas för att upptäcka lesioner i vit substans hos patienter med multipel skleros (MS), men sambandet mellan lesioner och klinisk funktionsnedsättning är svagt. På grund av detta har intresset för andra patologiska processer i hjärnan ökat. Exempel är förändringar i vit substans som ser normal ut vid MRT (NAWM) och även så kallad diffus vit vävnad (DAWM). Det är emellertid fortfarande oklart vilka mekanismer i MS som leder till klinisk funktionsnedsättning. Med kvantitativ MRT (qMRT) kan fysiologiska egenskaper i vävnaden, som till exempel relaxationstiderna (T1 och T2) samt protontäthet (PD), mätas. QMRT kan användas för att mäta förändringar i hjärnan hos MS patienter och des...

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Section: Qmri For Brain Imagingsupporting

confidence: 90%

Section: R1-r2-pd Spacementioning

confidence: 99%

Section: R1-r2-pd Spacementioning

confidence: 99%

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Quantitative Magnetic Resonance Imaging of the Brain : Applications for Tissue Segmentation and Multiple Sclerosis

West¹

2014

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“…As a consequence of different responses of the tissues to particular pulse sequences, this increases the capability of discrimination between different tissues (Fletcher et al, 1993;Vannier et al, 1985). The most common approach for multispectral MR image segmentation is pattern recognition (Bezdek et al, 1993;Suri, Singh, et al, 2002b).…”

Section: Self-organizing Maps (Som) Introduced By Kohonen In Early 1981mentioning

confidence: 99%

Segmentation of Brain MRI

Xu¹,

Luo²,

Ohya³

2012

Advances in Brain Imaging

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“…(See references [2][3][4][5][6][7][8] for examples of their work). A reoccurring problem is bringing students quickly up to speed on the principles of magnetic resonance so they can appreciate their research experience.…”

Section: Introductionmentioning

confidence: 99%

Teaching NMR Using Online Textbooks

Hornak

1999

Molecules

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Nuclear magnetic resonance (NMR) spectroscopy has almost become an essential analytical tool for the chemist. High-resolution one-and multi-dimensional NMR, timedomain NMR, and NMR microscopy are but a few of the NMR techniques at a chemist's disposal to determine chemical structure and dynamics. Consequently, even small chemistry departments are finding it necessary to provide students with NMR training and experience in at least some of these techniques. The hands-on experience is readily provided with access to state-of-the-art commercial spectrometers. Instruction in the principles of NMR is more difficult to achieve as most instructors try to teach NMR using single organic or analytical chemistry book chapters with static figures. This paper describes an online textbook on NMR spectroscopy called The Basics of NMR (http://www.cis.rit.edu/htbooks/nmr/) suitable for use in teaching the principles of NMR spectroscopy. The book utilizes hypertext and animations to present the principles of NMR spectroscopy. The book can be used as a textbook associated with a lecture or as a stand-alone teaching tool. Conference participants are encouraged to review the textbook and evaluate its suitability for us in teaching NMR spectroscopy to undergraduate chemistry majors.

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A multispectral analysis of brain tissues

Cited by 64 publications

References 25 publications

Quantitative Magnetic Resonance Imaging of the Brain : Applications for Tissue Segmentation and Multiple Sclerosis

Quantitative Magnetic Resonance Imaging of the Brain : Applications for Tissue Segmentation and Multiple Sclerosis

Segmentation of Brain MRI

Teaching NMR Using Online Textbooks

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