High spatial resolution and speed in MRSI

Nelson, Sarah J.; Vigneron, Daniel B.; Star-Lack, Joshua; Kurhanewicz, John

doi:10.1002/(sici)1099-1492(199712)10:8<411::aid-nbm496>3.0.co;2-8

Cited by 61 publications

(28 citation statements)

References 81 publications

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“…Typically, for MRSI, a large volume of interest can be selected and then phase encoding is applied to obtain multiple voxels in a single plane (Tzika et al, 1997) or in three-dimensions (Nelson et al, 1997c;Vigneron et al, 2001b). The advantage of obtaining multivoxel data is that it is possible to observe not only heterogeneity within the lesion but to examine surrounding tissue that may appear normal on MR images.…”

Section: Methodology For Acquiring Proton Mrsi Data In the Clinical Smentioning

confidence: 99%

“…Single-voxel MR spectroscopy has the inherent disadvantage that spectral data is not simultaneously collected from the tumor and its surrounding tissue, which greatly hinders the incorporation of valuable information in assessing therapeutic response (Kurhanewicz et al, 1996;Nelson et al, 1997a;Wald et al, 1997;Dillon and Nelson, 1999;Nelson, 2001). Due to technical difficulties, a limited number of adult brain tumor studies using advanced localized MR spectroscopy have been reported (Wald et al, 1995;Nelson et al, 1997b;Wald et al, 1997;Graves et al, 2001a;Vigneron et al, 2001a;Li et al, 2002), and even fewer studies have been carried out in children, employing advanced localized MRSI (Lazareff et al, 1996;Tzika et al, 1997;Lazareff et al, 1998;Taylor et al, 1998;Gonen et al, 1999;Lazareff et al, 1999;Tzika et al, 2001;Tzika et al, 2002;Tzika et al, 2003;Astrakas et al, 2004;Tzika et al, 2004).…”

Section: Application Of Brain Tumor Proton Mrsi In Childrenmentioning

confidence: 99%

See 1 more Smart Citation

Pediatric Brain Tumors: Magnetic Resonance Spectroscopic Imaging

Tzika¹,

Astrakas²,

Zarifi³

2011

Diagnostic Techniques and Surgical Management of Brain Tumors

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Section: Methodology For Acquiring Proton Mrsi Data In the Clinical Smentioning

confidence: 99%

Section: Application Of Brain Tumor Proton Mrsi In Childrenmentioning

confidence: 99%

Pediatric Brain Tumors: Magnetic Resonance Spectroscopic Imaging

Tzika¹,

Astrakas²,

Zarifi³

2011

Diagnostic Techniques and Surgical Management of Brain Tumors

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“…Fortunately, during a clinical imaging acquisition, these chemical shift differences are small, compared with the voxel sizes used in our images today, and we have to worry about (and correct for) only the chemical shift differences between water and fat. However, these same chemical shift differences can be used to produce MRS images that represent the chemical composition of tissue noninvasively in clinical subjects (12,13). This information can also be used to acquire MRS data on large tissue volumes for a similar analysis of the chemical composition of a tissue.…”

Section: Mrimentioning

confidence: 99%

“…As stated previously, MRI techniques can be used to measure important physiologic tissue properties that are related to function as well as anatomic information. These functional tissue properties include tissue diffusion, tissue permeability, and changes in blood oxygenation levels after neuronal activation (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). Overall, the MRI and MRS technologies should continue to prove extremely valuable in the clinical diagnosis and tracking of various disease processes.…”

Section: Mrimentioning

confidence: 99%

PET/MRI: The Blended-Modality Choice of the Future?

Bolus¹,

George²,

Washington³

et al. 2009

Journal of Nuclear Medicine Technology

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This article addresses the emerging technology of PET coupled with MRI, or PET/MRI, which could become the technology of choice in the future for many reasons. Some of these reasons will be discussed, along with a historical account of the field of MRI and how this modality has evolved to include many aspects of molecular and functional imaging. After reading this article, nuclear medicine technologists should be able to provide an overview of the history of MRI, discuss PET and how it is mainly used today melded to CT as PET/CT, discuss how MRI is used diagnostically, explain how PET technology and MRI technology are able to function simultaneously together as PET/MRI, discuss some issues concerning who will operate these new units, and discuss the possibility that PET/MRI could be the blended technology of choice in the future. In the beginning, there was a chemical identification technology known as nuclear magnetic resonance (NMR) spectroscopy. This technology was in the form of tabletop units, which were standard issue in research organic chemistry laboratories. Essentially, researchers discovered that by putting organic chemicals in a strong magnetic field, hydrogen atoms would orient themselves along the strong magnetic field. When this magnetic field was switched off, hydrogen atoms would relax back to their equilibrium state and in the process give off a radiofrequency energy signal. The energy or spectral signatures of these signals could identify them as coming from hydrogen atoms attached to different molecules. Overall, these energy spectra were the basis of NMR spectroscopy and gave scientists the ability to detect unique fingerprints for different chemicals.In the 1970s, this same spectroscopic technology was expanded into the diagnostic imaging realm. Essentially, scientists developed the ability to apply the same NMR signal as is used in spectroscopy studies to a technology that was able to scan an entire organ system. This technology was first demonstrated in organic objects such as fruits and then in animal organ systems, and then it quickly was extended to humans.The initial technologic challenge was to build instruments large enough to scan a human yet robust enough to maintain strong and stable magnetic fields over long periods. This challenge was finally met with the advent of magnets constructed with materials able to operate in the superconductive realm (i.e., the realm in which electrical energy loss due to resistive losses is near zero). In the early to mid 1980s, when NMR first emerged as a widespread clinical imaging modality, it originally fell under the domain of nuclear medicine technology as an offshoot of nuclear medicine. Additionally, the very first NMR technologists were nuclear medicine technologists. Furthermore, some of the more progressive nuclear medicine technology educational programs taught NMR physics and provided students with opportunities to experience clinical rotations in NMR. Unfortunately, once the modality began to mature and after Medicare began to reimburse...

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“…corresponding to (4). From the computational point of view, this LS solution boils down to a simple K × K matrix inversion; i.e., the algorithm is as efficient as classical SLIM.…”

Section: For Each Time Point T 0 Compute the Ls Solutionmentioning

confidence: 99%

Improved MRSI with field inhomogeneity compensation

et al. 2006

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Magnetic resonance spectroscopy imaging (MRSI) is a promising and developing tool in medical imaging. Because of various difficulties imposed by the imperfections of the scanner and the reconstruction algorithms, its applicability in clinical practice is rather limited. In this paper, we suggest an extension of the constrained reconstruction technique (SLIM). Our algorithm, named B-SLIM, takes into account the the measured field inhomogeneity map, which contains both the scanner's main field inhomogeneity and the object-dependent magnetic susceptibility effects. The method is implemented and tested both with synthetic and physical two-compartment phantom data. The results demonstrate significant performance improvement over the SLIM technique. At the same time, the algorithm has the same computational complexity as SLIM.

show abstract

High spatial resolution and speed in MRSI

Cited by 61 publications

References 81 publications

Pediatric Brain Tumors: Magnetic Resonance Spectroscopic Imaging

Pediatric Brain Tumors: Magnetic Resonance Spectroscopic Imaging

PET/MRI: The Blended-Modality Choice of the Future?

Improved MRSI with field inhomogeneity compensation

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