Search results for "Echoencephalography"
showing 8 items of 8 documents
Transcranial Doppler ultrasound study of the effects of nitrous oxide on cerebral autoregulation during neurosurgical anesthesia: a randomized contro…
2003
Object. Nitrous oxide has an adverse effect on cerebrovascular hemodynamics. Increased intracranial pressure, cerebral blood flow (CBF), cerebral metabolic rate of O2 (CMRO2), and reduced autoregulation indices have been reported, but their magnitudes are still being debated. This study was designed to evaluate the effect of N2O on CBF and autoregulatory indexes during N2O—sevoflurane anesthesia in a prospective randomized controlled series of patients. Methods. Two groups of 20 patients were studied on the basis of the use of N2O in the anesthetic gas mixture. The transient hyperemic response test, which relies on transcranial Doppler ultrasound techniques, was used to assess cerebral hemo…
Hyperechogenicity of the substantia nigra in healthy controls is related to MRI changes and to neuronal loss as determined by F-Dopa PET
2009
Abstract Transcranial ultrasound (TCS) has been shown to reveal hyperechogenicity of the substantia nigra (SN) in Parkinsonian patients and in about 10% of healthy controls. It is hypothesized that SN hyperechogenicity in healthy subjects is a vulnerability marker for idiopathic Parkinson's disease (IPD). Although there is strong evidence that the echomarker results from increased local iron content, the exact pathophysiological mechanisms remain incompletely understood. Thus, prognostic impact can only be estimated. We examined 14 subjects with SN hyperechogenicity (SN+) (7 IPD patients and 7 controls) and 7 healthy controls without the echomarker (SN−) by a magnetic resonance imaging meth…
CT-guided stereotactic biopsy aided by Doppler ultrasonic vascular monitoring
1992
The use of a 20 MHz pulsed Doppler technique during stereotactic brain tumour biopsies is described. By means of a miniaturized ultrasonic probe the tissue planned for biopsy was investigated for vessel signals. Out of 41 patients, with this technique a flow-pulse curve in front of the biopsy cannula was registered in 14 cases. In 9 cases one pulse curve was determined and in 5 cases two or more flow curves were found, indicating the presence of arterial vessels. The depth of the vessels signal could be localized and this area avoided for biopsy sampling. In a series of 41 stereotactic biopsies carried out in this way there was no intra-operative haemorrhage or postoperative haematoma.
Endo-neuro-sonography: principles and 3-D technique
1997
To evaluate the usefulness of transendoscopic sonography we studied two new sono probes 6 F in diameter in 17 fresh specimens. We saw precise imaging of well-known anatomical structures and also gained an additional dimension in endoscopy, as the sono adds to the endo-view a transverse scan like a mini-CT at the tip of the probe. We also experienced the navigation characteristic of this imaging technique, both in real time and on line. Some 3-D reconstructions of the ventricular system were examined. The equipment has been used in clinical practice and must now be adapted for neurosurgery.
Battered child syndrome: cerebral ultrasound and CT findings after vigorous shaking.
1992
Child abuse by whiplash-shaking can lead to severe cerebral damage, neurological defects and mental retardation. Cerebral damage has been found with and without external evidence of head injury. We report the sonographic findings in two children after traumatization due to repetitive vigorous whiplash shaking. Cerebral sonography revealed cerebral edema at admission or within 48 hours thereafter. Follow-up studies demonstrated development of marked brain atrophy in both cases. The sonographic findings were confirmed by cranial computerized tomography. Doppler sonography was used to monitor cerebral perfusion by measuring intracranial blood flow. The clinical history of the patients demonstr…
Examination of the fetal brain by transabdominal three-dimensional ultrasound: potential for routine neurosonographic studies
2006
Objective To evaluate the role of transabdominal three-dimensional (3D) ultrasound in the assessment of the fetal brain and its potential for routine neurosonographic studies. Methods We studied prospectively 202 consecutive fetuses between 16 and 24 weeks' gestation. A 3D ultrasound volume of the fetal head was acquired transabdominally. The entire brain anatomy was later analyzed using the multiplanar images by a sonologist who was expert in neonatal cranial sonography. The quality of the conventional planes obtained (coronal, sagittal and axial, at different levels) and the ability of the 3D multiplanar neuroscan to visualize properly the major anatomical structures of the brain were eva…
Beziehung zwischen Kopfumfang und sonographischer Morphometrie der Ventrikelstrukturen im Neugeborenen- und Säuglingsalter
2001
AIM: To determine normal values of sonographic measurements of the brain in neonates and infants. METHOD: Cerebral ultrasonographic examinations were performed in 143 healthy newborns and infants. The size of the ventricles was determined by ascertaining distances as well as performing planimetric measurements of the ventricular area and circumference in standardized planes. RESULTS: Throughout the course of the study we observed a continous increase in size and a strong correlation with head circumference. The middle coronary plane used for the measurements allows the accurate representation of the ventricles and a more objective assessment of size. CONCLUSION: Based on the morphometric da…
Endo-neuro-sonography: anatomic aspects of the ventricles.
1997
To evaluate the usefulness of transendoscopic sonography, we have studied the use of a new sonographic probe of 6 F diameter in 11 fresh specimens. We achieved a precise imaging of well known anatomic structures and, moreover, obtained an additional dimension in endoscopy, since the sonographic probe adds a transverse scan to the endoscopic view, like a mini-CT at the tip of the probe. In this way, we also examined the guiding characteristics of this imaging technique, both in real time and on-line. Our results promise further interesting aspects of this technique in minimally invasive neurosurgery and suggest that further development and clinical experience seem to be justified.