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Metabolic Imaging (metabolic + imaging)

Distribution by Scientific Domains
Medical Sciences85%

Selected Abstracts

Metabolic imaging in the anesthetized rat brain using hyperpolarized [1- 13C] pyruvate and [1- 13C] ethyl pyruvate

MAGNETIC RESONANCE IN MEDICINE, Issue 5 2010
Ralph E. Hurd
Abstract Formulation, polarization, and dissolution conditions were developed to obtain a stable hyperpolarized solution of [1- 13C]-ethyl pyruvate. A maximum tolerated concentration and injection rate were determined, and 13C spectroscopic imaging was used to compare the uptake of hyperpolarized [1- 13C]-ethyl pyruvate relative to hyperpolarized [1- 13C]-pyruvate into anesthetized rat brain. Hyperpolarized [1- 13C]-ethyl pyruvate and [1- 13C]-pyruvate metabolic imaging in normal brain is demonstrated and quantified in this feasibility and range-finding study. Magn Reson Med 63:1137,1143, 2010. © 2010 Wiley-Liss, Inc. [source]

Application of subsecond spiral chemical shift imaging to real-time multislice metabolic imaging of the rat in vivo after injection of hyperpolarized 13C1 -pyruvate

MAGNETIC RESONANCE IN MEDICINE, Issue 3 2009
Dirk Mayer
Abstract Dynamic nuclear polarization can create hyperpolarized compounds with MR signal-to-noise ratio enhancements on the order of 10,000-fold. Both exogenous and normally occurring endogenous compounds can be polarized, and their initial concentration and downstream metabolic products can be assessed using MR spectroscopy. Given the transient nature of the hyperpolarized signal enhancement, fast imaging techniques are a critical requirement for real-time metabolic imaging. We report on the development of an ultrafast, multislice, spiral chemical shift imaging sequence, with subsecond acquisition time, achieved on a clinical MR scanner. The technique was used for dynamic metabolic imaging in rats, with measurement of time-resolved spatial distributions of hyperpolarized 13C1 -pyruvate and metabolic products 13C1 -lactate and 13C1 -alanine, with a temporal resolution of as fast as 1 s. Metabolic imaging revealed different signal time courses in liver from kidney. These results demonstrate the feasibility of real-time, hyperpolarized metabolic imaging and highlight its potential in assessing organ-specific kinetic parameters. Magn Reson Med, 2009. © 2009 Wiley-Liss, Inc. [source]

Molecular imaging of regional brain tumor biology

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue S39 2002
A.M. Spence
Abstract Energy metabolism measurements in gliomas in vivo are now performed widely with positron emission tomography (PET). This capability has developed from a large number of basic and clinical science investigations that have cross fertilized one another. This article presents several areas that exemplify questions that have been explored over the last two decades. While the application of PET with [18F]-2-fluoro-2-deoxyglucose (FDG-PET) has proven useful for grading and prognosis assessments, this approach is less clinically suitable for assessing response to therapy, even though results to date raise very intriguing biological questions. Integration of metabolic imaging results into glioma therapy protocols is a recent and only preliminarily tapped method that may prove useful in additional trials that target DNA or membrane biosynthesis, or resistance mechanisms such as hypoxia. There are exciting future directions for molecular imaging that will undoubtedly be fruitful to explore, especially apoptosis, angiogenesis and expression of mutations of genes, e.g., epidermal growth factor receptor, that promote or suppress cellular malignant behavior. J. Cell. Biochem. Suppl. 39: 25,35, 2002. © 2002 Wiley-Liss, Inc. [source]

Metabolic imaging in the anesthetized rat brain using hyperpolarized [1- 13C] pyruvate and [1- 13C] ethyl pyruvate

MAGNETIC RESONANCE IN MEDICINE, Issue 5 2010
Ralph E. Hurd
Abstract Formulation, polarization, and dissolution conditions were developed to obtain a stable hyperpolarized solution of [1- 13C]-ethyl pyruvate. A maximum tolerated concentration and injection rate were determined, and 13C spectroscopic imaging was used to compare the uptake of hyperpolarized [1- 13C]-ethyl pyruvate relative to hyperpolarized [1- 13C]-pyruvate into anesthetized rat brain. Hyperpolarized [1- 13C]-ethyl pyruvate and [1- 13C]-pyruvate metabolic imaging in normal brain is demonstrated and quantified in this feasibility and range-finding study. Magn Reson Med 63:1137,1143, 2010. © 2010 Wiley-Liss, Inc. [source]

Application of subsecond spiral chemical shift imaging to real-time multislice metabolic imaging of the rat in vivo after injection of hyperpolarized 13C1 -pyruvate

MAGNETIC RESONANCE IN MEDICINE, Issue 3 2009
Dirk Mayer
Abstract Dynamic nuclear polarization can create hyperpolarized compounds with MR signal-to-noise ratio enhancements on the order of 10,000-fold. Both exogenous and normally occurring endogenous compounds can be polarized, and their initial concentration and downstream metabolic products can be assessed using MR spectroscopy. Given the transient nature of the hyperpolarized signal enhancement, fast imaging techniques are a critical requirement for real-time metabolic imaging. We report on the development of an ultrafast, multislice, spiral chemical shift imaging sequence, with subsecond acquisition time, achieved on a clinical MR scanner. The technique was used for dynamic metabolic imaging in rats, with measurement of time-resolved spatial distributions of hyperpolarized 13C1 -pyruvate and metabolic products 13C1 -lactate and 13C1 -alanine, with a temporal resolution of as fast as 1 s. Metabolic imaging revealed different signal time courses in liver from kidney. These results demonstrate the feasibility of real-time, hyperpolarized metabolic imaging and highlight its potential in assessing organ-specific kinetic parameters. Magn Reson Med, 2009. © 2009 Wiley-Liss, Inc. [source]

T2*-weighted magnetic resonance imaging with hyperoxia in acute ischemic stroke

ANNALS OF NEUROLOGY, Issue 1 2010
Krishna A. Dani MBChB
Objective We describe the first clinical application of transient hyperoxia ("oxygen challenge") during T2*-weighted magnetic resonance imaging (MRI), to detect differences in vascular deoxyhemoglobin between tissue compartments following stroke. Methods Subjects with acute ischemic stroke were scanned with T2*-weighted MRI and oxygen challenge. For regions defined as infarct core (diffusion-weighted imaging lesion) and presumed penumbra (perfusion-diffusion mismatch [threshold = Tmax ,4 seconds], or regions exhibiting diffusion lesion expansion at day 3), T2*-weighted signal intensity,time curves corresponding to the duration of oxygen challenge were generated. From these, the area under the curve, gradient of incline of the signal increase, time to maximum signal, and percentage signal change after oxygen challenge were measured. Results We identified 25 subjects with stroke lesions >1ml. Eighteen subjects with good quality T2*-weighted signal intensity,time curves in the contralateral hemisphere were analyzed. Curves from the diffusion lesion had a smaller area under the curve, percentage signal change, and gradient of incline, and longer time to maximum signal (p < 0.05, n = 17) compared to normal tissue, which consistently showed signal increase during oxygen challenge. Curves in the presumed penumbral regions (n = 8) showed varied morphology, but at hyperacute time points (<8 hours) showed a tendency to greater percentage signal change. Interpretation Differences in T2*-weighted signal intensity,time curves during oxygen challenge in brain regions with different pathophysiological states after stroke are likely to reflect differences in deoxyhemoglobin concentration, and therefore differences in metabolic activity. Despite its underlying complexities, this technique offers a possible novel mode of metabolic imaging in acute stroke. ANN NEUROL 2010;68:37,47 [source]