Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q9BWK5 (MRI)
 85,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We used a multitracer positron emission tomography (PET) approach to assess metabolic changes in infarcted and periinfarct tissue in acute ischaemic stroke. 16 patients were studied within 6-48 hours (mean, 23 h) after onset of symptoms from a first hemispheric stroke and again 13-25 days later (mean, 15.6 days). Regional cerebral metabolic rates of oxygen (CMRO2) and glucose (CMRGlc), blood flow (CBF) and blood volume (CBV) were measured and oxygen extraction (OEF) as well as glucose extraction (GEF) and microvascular transit time were calculated. PET images were three-dimensionally aligned using serial CT or MRI scans. Regions of interest on the side of the infarction were individually compared to contralateral mirror regions. In the infarction core CBF, CMRO2 and CMRGlc were significantly lower than on the contralateral side and did not change during time. In the periinfarct regions there was a decreased CMRO2 with progressive deterioration over time while CBF slightly increased. Only in a few ischaemic regions with initially increased OEF oxygen metabolism was preserved during the course of time.
 ...
PMID:Metabolic derangement in viable periinfarct tissue in the course of acute ischaemic infarction: a multitracer positron emission tomography (PET) study. 135 84

Twenty-four patients presenting an acute stroke with watershed cerebral infarct on CT scan or MRI were included in this retrospective study. Age was 63 +/- 14 years (mean +/- SD), and sex ratio was 2 men for 1 woman. Main clinical features were: in anterior location, lower limb weakness and frontal syndrome with transcortical motor aphasia in left lesions or spatial dyscalculia in right ones; in posterior location, brachiofacial weakness with constant quadranopsia and hypoesthesia, and Gerstmann syndrome in left lesion. There was no distinctive feature for subcortical and multiple infarcts. In bilateral infarcts, there were one pseudobulbar syndrome, and 2 pseudo brainstem syndromes with neuropsychological signs. Aetiologies were severe carotid artery disease in 14 cases, severe cardiopathy in 6, isolated cerebral angiitis in 1, essential thrombocythemia in 1, protein C deficiency with sickle cell disease in 1, and cholesterol emboli in 1 anatomical case. CBF performed in carotid artery occlusions or tight stenoses showed evidence of haemodynamic changes. Microembolic process can be proposed in the case with cholesterol emboli. Preventive treatment is discussed.
 ...
PMID:Watershed cerebral infarcts: retrospective study of 24 cases. 135

We compared the relative sensitivity of two interictal PET techniques, bolus injection of [15O] labeled water for estimation of cerebral blood flow (H2(15)O CBF-PET), and 18F 2-deoxyglucose (18FDG-PET) for cerebral glucose metabolism (CMRglc), and T2-weighted magnetic resonance imaging, in 28 patients with medically intractable complex partial seizures undergoing evaluation for surgery. There were statistically significant associations between lateralization by 18FDG-PET, and MRI, but not H2(15)O CBF-PET, and lateralization of the epileptic focus as defined by scalp-sphenoidal ictal EEG. Fifteen patients had surgery or subdural electrodes. 18FDG-PET was more closely associated with a good outcome than H2(15)O CBF-PET, which, in addition, showed hypoperfusion contralateral to the epileptic temporal lobe in several cases. H2(15)O sensitivity may have been reduced by technical factors, but 18FDG-PET appears to be more specific for localization of epileptic zones.
 ...
PMID:Comparison of PET measurements of cerebral blood flow and glucose metabolism for the localization of human epileptic foci. 146

A method for the noninvasive, quantitative determination of regional cerebral blood flow (rCBF) in small laboratory animals, such as the rat, is described. The change in magnetic susceptibility in the vicinity of brain capillaries evoked by iv infusion of Gd(DTPA), a paramagnetic agent not crossing the blood-brain barrier, is detected as an attenuation of the 1H signal in T2-weighted MRI sequences. The reduction of the MR signal intensity after 1 or 2 min of Gd(DTPA) infusion correlates well (r greater than 0.95) with the rCBF values obtained using the well-established [14C]iodoantipyrine method. At a slice thickness of 3 mm, the pixel size typically is 0.15 x 0.5 mm2. The clearance rate of Gd(DTPA) from blood allows repeated measurements of CBF to be made using this technique approximately every 30 min. The experimental results obtained in normal and ischemic rat brain have been rationalized within the frame of a two-compartment model, allowing the definition of optimal experimental conditions for a given CBF: for normal and reduced CBF values (less than 150 ml/100 g/min) the reduction in MR signal intensity, measured after 1 or 2 min of Gd (DTPA) infusion, correlates closely with the CBF. However, for CBF values greater than 150 ml/100 g/min, a more reliable parameter would be the time constant of the MR signal attenuation during the infusion.
 ...
PMID:Noninvasive determination of regional cerebral blood flow in rats using dynamic imaging with Gd(DTPA) 159 54

We have tomographically mapped changes in the blood brain barrier (BBB) (99 mTc Pertechnetate) in 20 patients with acute contusions, and four with acute subdural haematomas in situ. The changes were related to regional CBF, (99 mTc HMPAO SPECT) T2 weighted MRI scans, CT abnormalities and the clinical features. Seventy-five percent of contusions were accompanied by a BBB abnormality, usually a "halo" around the lesion, which was more common in scans made after the second day. All contusions demonstrated "oedema" as a zone of "T2" signal on MRI or a zone of lucency on CT, and all were accompanied by a focal zone of low CBF on SPECT. Early contusional oedema appears to be cytotoxic but in certain cases, delayed blood brain barrier lesions develop, suggesting a vasogenic component.
 ...
PMID:The time course of vasogenic oedema after focal human head injury--evidence from SPECT mapping of blood brain barrier defects. 208 18

Both CBF and CBV were evaluated by gamma-camera SPECT in 14 patients with classic migraine, all studied while symptom-free. Nuclear data were correlated with CT and MRI. A decreased regional CBF was observed in 13 of the 14 patients. The decreased perfusion was localized in the frontal lobe in 6 patients, the temporal lobe in one, the parietal lobe in 11 and the occipital lobe in 5 patients. The parieto-occipital cortex was involved more often than the frontal cortex; the association of hypoperfusion with parieto-occipital cortex was quite high. The right parieto-occipital regions were affected more often than the left ones. Regional CBV was increased in 8 patients. There was good topographical concordance between decreased CBF and increased CBV, but the increase of CBV was in general more evident at the periphery of the hypoperfusion. It is of interest that the only patient with a normal CBF study had a pathological CBV study. Apparently, CBF derangements are very common in symptom-free patients with classic migraine, a CBF decrease being often accompanied by a CBV increase. In these patients both CT and MRI have a lower diagnostic yield than SPECT.
 ...
PMID:Cerebral blood flow and volume in symptom-free migraineurs: a SPECT study. 217 53

Medullary Venous Malformation with an aneurysm is uncommon and only 4 cases have been reported in previous papers. We reported a case of a medullary venous malformation (MVM) of the frontal lobe with an aneurysm on its proximal artery. A 48 year old female with numbness of right fingers visited our hospital. On the CT scan, an abnormal enhanced area was found inside the left frontal lobe. The left carotid angiography showed both of an aneurysm around A com A in early arterial phase, and "MVM with early blush" in capillary-early venous phase. MRI showed linear signal void crossing the cortex to join paraventricular low intensity area (LIA) with slight cortical atrophy on sagittal slice. The CBF study by Xe-SPECT proved a high flow lesion, with mean CBF 69 (left), 59 (right) mg/100 g brain/min, Protective operation only for aneurysm was performed. The MVM in our case was proved to be a "high flow-low resistance system" by CBF study, although MVM has been considered a "low flow system". Reviewing papers, there were 3 cases of "high flow MVMs" confirmed by the measurement of CBF, all of them were large sized (greater than 4 cm) and with early blush angiographically. We conclude that large sized MVM with early blush needs hemodynamic inspection and special care to prevent "high flow MVMs" from hemorrhage and the steal.
 ...
PMID:[High flow medullary venous malformation with aneurysm on the proximal artery--a case report]. 220 55

We encountered two cases of typical transient global amnesia (a 53-year-old woman and a 50-year-old man). Both cases showed no evidence of abnormal findings which caused the attack on examinations of CSF, EEG, brain CT, brain MRI and cerebral angiography. Examinations of positron emission tomography, using 15O labeled CO2 and O2, were performed on 14 and 8 days after the attack in the female and male cases, respectively, and those disclosed decreased regional blood flow (CBF), increased oxygen extraction ratio (OER), and decreased oxygen metabolic ratio (CMRO2) in the bilateral medial temporal and occipital lobes, which were supplied by the bilateral posterior cerebral arteries. PET, performed on about one month after the attack, revealed normalized values of CBF, OER, CMRO2 in both cases. These findings strongly suggested that transient global amnesia in our cases may be related to ischemia of the bilateral posterior cerebral arteries.
 ...
PMID:[Positron emission tomography in two cases of transient global amnesia]. 279 10

All the papers were of a high scientific standard, giving us clearly defined information that will be applicable in the diagnosis and further management of infantile hydrocephalus. Particularly interesting subjects were the comparison of CT and MRI in the evaluation of hydrocephalus and cine MRI, which allows evaluation of the CSF dynamic flows. CBF measurements with xenon CT/CBF imaging or transcranial Doppler examinations of CBF velocity are used much more for evaluation of the shunt indications for shunting and also for definition of the outcome of shunting procedures. Although measurements of physiological CSF parameters are important, studies on the pathophysiology of hydrocephalus should be focused on the changes in CBF in hydrocephalus patients. The key points and conclusions presented by each author are discussed and the prospects mentioned for the future in neuroimaging and functional examination in hydrocephalus.
 ...
PMID:Neuroimaging and functional examination in hydrocephalus: a comment. 758 86

The authors present the policy they have worked out for hydrocephalus patients with special reference to the pressure measurement and test methods and to rCBF, SPECT and transcranial Doppler sonography (TDC) studies. For diagnosis, the protocol proposed by Gjerris and Borgesen was followed in 75 cases: besides other methods (CT, radionuclide cisternography, MRI) the intracranial pressure waves routinely recorded and analyzed by means of ventricular catheters for 24 h. The patients were roughly divided into groups in terms of diagnosis, baseline pressure, compliance, results of infusion tests and of surgery. In 13 patients the investigations were supplemented by rCBF SPECT and in 42 patients by TCD studies before and after CSF shunting or withdrawal to analyze the acute effects on cerebral circulation. Clinical follow-up shows that need for shunting was indicated fairly well by the common results of baseline ICP, compliance and infusion loading. The rCBF SPECT studies revealed a significant increase of the cerebral perfusion at the basal ganglia after shunting while, on the basis of CBF velocity changes three types of vasoregulatory response could be defined with TCD. In our hands, monitoring of the pressure and craniospinal capacity has proved to be a valuable aid in decisions on surgery; however, for a more precise (and beneficial) appreciation of whether surgery is indicated the vasoregulatory responses should also be taken into account in future.
 ...
PMID:Our policy in diagnosis and treatment of hydrocephalus. 775 7


1 2 3 4 5 6 7 8 9 10 Next >>