Learn More
Several MR methods have been proposed over the last decade to obtain quantitative estimates of the tissue blood oxygen saturation (StO2) using a quantification of the blood oxygen level dependent effect. These approaches are all based on mathematical models describing the time evolution of the MR signal in biological tissues in the presence of magnetic(More)
Knowledge of the blood volume per unit volume of brain tissue is important for understanding brain function in health and disease. We describe a direct method using two-photon laser scanning microscopy to obtain in vivo the local capillary blood volume in the cortex of anesthetized mouse. We infused fluorescent dyes in the circulating blood and imaged the(More)
Tumors create a heterogeneous acidic microenvironment which assists their growth and which must be taken into account in the design of drugs and their delivery. In addition, the acidic extracellular pH (pHe) is itself exploited in several experimental techniques for drug delivery. The way the acidity is created is not clear. We report here the spatial(More)
This study has shown that murine monocytes/macrophages (Mo/Ma) can be labeled simply and efficiently with large, green-fluorescent, micrometer-sized particles of iron-oxide (MPIO). Neither size nor proliferation rate of the Mo/Ma is significantly affected by this labeling. The labeled Mo/Ma have been administered intravenously to rats that had developed a(More)
This study aimed at combining an iron-based, steady-state, vessel size index magnetic resonance imaging (VSI MRI) approach, and a gadolinium (Gd)-based, dynamic contrast-enhanced MRI approach (DCE MRI) to characterize tumoral microvasculature. Rats bearing an orthotopic glioma (C6, n=14 and RG2, n=6) underwent DCE MRI and combined VSI and DCE MRI 4 h later,(More)
PURPOSE Synchrotron microbeam radiation therapy (MRT) relies on spatial fractionation of the incident photon beam into parallel micron-wide beams. Our aim was to analyze the effects of MRT on normal brain and 9L gliosarcoma tissues, particularly on blood vessels. METHODS AND MATERIALS Responses to MRT (two arrays, one lateral, one anteroposterior (2 × 400(More)
Microbeam Radiation Therapy (MRT) is a preclinical form of radiosurgery dedicated to brain tumor treatment. It uses micrometer-wide synchrotron-generated X-ray beams on the basis of spatial beam fractionation. Due to the radioresistance of normal brain vasculature to MRT, a continuous blood supply can be maintained which would in part explain the surprising(More)
The aim of this study was to compare magnetic resonance imaging (MRI) and histological estimates of the mean vessel diameter (mVD), the vessel density (Density), and the vessel size index (VSI) obtained in the same tumor-bearing animals. Twenty-seven rats bearing intracranial glioma (C6 or RG2) were imaged by MRI. Changes in transverse relaxations (ΔR 2*(More)
Lactate (Lac) and mobile lipids (Lip), which are present in rat gliomas, are difficult to map because their 1H resonances overlap in the 1.3 ppm region. 2D J-resolved spectroscopy enables proper separation of the two resonance lines. To obtain high-spatial-resolution mapping of Lac and Lip resonances within a reasonable experiment time, we coupled 2D(More)
Vessel size index (VSI), a parameter related to the distribution of vessel diameters, may be estimated using two MRI approaches: (i) dynamic susceptibility contrast (DSC) MRI following the injection of a bolus of Gd-chelate. This technique is routinely applied in the clinic to assess intracranial tissue perfusion in patients; (ii) steady-state(More)