Learn More
The effect of focal ischemia on tissue pH was studied at various times up to 6 hours after permanent middle cerebral artery occlusion in rats. Tissue pH was imaged by using umbelliferone fluorescence and correlated with cerebral blood flow, ATP content, and recordings of the steady potential. Circumscribed foci of allalosis (pH 7.32+/-0.11) were detected(More)
The quantitative NMR parameters T1, T2, rho, and apparent diffusion coefficient (ADC) were determined during the 7 h after middle cerebral artery occlusion in rats. In the normal caudate-putamen (CP), 869 +/- 145 ms and 72 +/- 2 ms for T1 and for T2, respectively, were found; the corresponding values for cortex were 928 +/- 117 ms and 73 +/- 2 ms. The ADC(More)
Focal cerebral ischaemia was produced in 11 rats by permanent occlusion of the right middle cerebral artery (MCA) using a suture model modified to enable manipulation with the animals in situ in an NMR spectrometer. The development of the ischaemic insults and the resultant infarcts were observed for up to 6 h by localized 1H MRS and diffusion-weighted MRI(More)
Previous magnetic resonance (MR) investigations of middle cerebral artery (MCA) occlusion in rats were limited by the lack of early post-occlusion MR measurements and/or electrophysiological monitoring. Therefore, we have developed a technique which allows to perform MCA occlusion inside the magnet under simultaneous recording of EEG and direct current (DC)(More)
High speed magnetic resonance imaging (MRI) and short diffusion times are used to investigate the appearance of restricted diffusion in three different models of cerebral infarction. The models are: the middle cerebral artery occlusion (MCAO) model in the rat, the carotid occlusion model in the gerbil, and the Rose Bengal microvascular occlusion model in(More)
Focal cerebral ischemia causes rapid intensity changes in diffusion-weighted images (DWI) and elevated lactate as detected by localized proton spectroscopy (1H-MRS). To investigate whether such changes can also be evoked by perischemic depolarizations, we combined DWI and 1H-MRS measurements with DC potential recordings. About 40 min after occlusion of the(More)
The effect of the glutamate antagonist MK-801 on the ischemic threshold of energy metabolism and protein synthesis (CPS) was studied in rats submitted to 3 h occlusion of the left middle cerebral artery (MCA). Local blood flow and CPS were measured by double tracer autoradiography, and local ATP content by bioluminescence imaging. In untreated animals(More)
An infant presented with a rare cervical (non-terminal) myelocystocele as a congenital skin-covered mass located in the midline of the posterior aspect of her neck. Magnetic resonance (MR) imaging and computed tomography showed a cystic mass filled with cerebrospinal fluid in the midline of the posterior aspect of the neck, with a fibrous streak extending(More)
The contrast between edema and F98 glioma in rat brain was distinctly enhanced in T2-weighted MRI (TE 130 ms, TR 3 s) by intraperitoneal injection of the synthetic gadolinium-porphyrin complex, GdTPPS. The T1 relaxation time of the gliomas was selectively shortened by about 50% from 1339 +/- 109 ms to 628 +/- 106 ms, and the T2 relaxation time was shortened(More)