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Journal of Cerebral Blood Flow & Metabolism, 2013

Neuroscience, 2013

and sharing with colleagues.

Scandinavian Journal of Clinical & Laboratory Investigation, 1968

Journal of Cerebral Blood Flow & Metabolism, 1985

A new technique that requires neither arterial blood sampling nor prior knowledge of the indicator's tissue-blood partition coefficient has been developed for quantitation of local CBF. This technique arises from an existing method that uses the inert, freely diffusible gas eous tracer [18F]methyl fluoride (CH318F) and positron computed tomography. The shape of the arterial blood curve is derived from continuous sampling of expired air. The concentration of CH318F in the arterial blood is as sumed to be proportional to the expired gas curve inter polated between end-tidal values. The absolute scale of the blood curve is determined by fitting a series of venous blood samples to a multicompartment model. Four vali-Methods for measuring CBF using inert, freely diffusible indicators originated > 35 years ago with the work of Schmidt (1945, 1948). Since the time of those pioneer efforts, modifications of the basic technique have been extensively investi gated by many groups. The development of posi tron computed tomography (PCT) has aided this ef fort considerably. The three-dimensional imaging capability permits the delineation of cerebral struc tures, thereby providing flow information on a local instead of a global or regional level. More impor tantly, the ability of PCT to quantitate radioactivity concentrations in small regions of tissue offers a

Stroke, 2005

Magnetic Resonance in Medicine, 2013

Purpose-Cerebral blood volume (CBV) changes in many diverse pathologic conditions, and in response to functional challenges along with changes in blood flow, blood oxygenation, and the cerebral metabolic rate of oxygen. The feasibility of a new method for non-invasive quantification of absolute cerebral blood volume that can be applicable to the whole human brain was investigated. Methods-Multi-slice data were acquired at 3 T using a novel inversion recovery echo planar imaging (IR-EPI) pulse sequence with varying contrast weightings and an efficient rotating slice acquisition order, at rest and during visual activation. A biophysical model was used to estimate absolute cerebral blood volume at rest and during activation, and oxygenation during activation, on data from 13 normal human subjects. Results-Cerebral blood volume increased by 21.7% from 6.6±0.8 mL/100 mL of brain parenchyma at rest to 8.0±1.3 mL/100 mL of brain parenchyma in the occipital cortex during visual activation, with average blood oxygenation of 84±2.1% during activation, comparing well with literature. Conclusion-The method is feasible, and could foster improved understanding of the fundamental physiological relationship between neuronal activity, hemodynamic changes, and metabolism underlying brain activation; complement existing methods for estimating compartmental changes; and potentially find utility in evaluating vascular health.

Seminars in Roentgenology, 2010

W ith advances in magnetic resonance imaging (MRI) technologies, new powerful techniques emerge that are immensely valuable in solving clinical problems. The objectives of this article are to review the basic principles and the clinical applications of the most commonly used advanced magnetic resonance (MR) neuroimaging techniques such as diffusion, spectroscopy, and perfusion imaging.

2012

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Conference Proceedings. 2nd International IEEE EMBS Conference on Neural Engineering, 2005.

With the recent development, magnetic resonance imaging went beyond the anatomical and morphological imaging and gave information about physiological properties of the tissues [1]. Anatomical images with high resolution could be get by MRI using a combination of rapid imaging techniques and bolus injection of extracellular contrast agents. Perfusion weighted MRI (PWI) has been used in clinical practices since 1989 [2,3]. The contrast agents cause a signal change and the change over time can be analyzed to evaluate important cerebral hemodynamics like, cerebral blood volume (CBV), cerebral blood flow (CBF) and mean transit time (MTT) [4]. In this study, MATLAB software has been used for writing codes for both mathematical equations and graphical user interface. As well as perfusion maps, we aimed to develop an easy-to-use interface so that technicians could run the program on site in a few minutes. User can achieve all operations easily, see information about patient and study, review all MR images in cine-mode, learn the absolute values of the regions, change colormaps of the results and save results in different image formats. All results of 11 patients with different clinical presentations were compared with another commercial software and for these patients three different statistics tables of comparison were given.

Journal of Cerebral Blood Flow & Metabolism, 1989

Abbreviations used: EDRF, endothelium-derived relaxing fac tor; GABA, ,),-aminobutyrate; LCGU, local cerebral glucose uti lization; MPTP, N-methyl-4-phenyl-I,2,3,6-tetrahydropyridine; NMDA, N-methyl-o-aspartate; PET, positron emission tomog raphy; SPECT, single photon emission computed tomography; rCBF, regional CBF.