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Biomedical subjects

R Ethier

Publications and source records attributed to R Ethier.

At least 73 records · Page 4Linked to original sources
PubMed1979

Computerized tomography findings in arteriovenous malformations of the brain.

Computerized tomography (CT) scans of 54 patients with an arteriovenous malformation (AVM) of the brain were reviewed. The 31 males and 23 females (mean age: 33 years) were classified according to clinical presentation: 1) intracranial hemorrhage (30 patients); 2) seizure disorder (19 patients); and 3) other neurological disturbance (five patients). A brain hematoma was identified in all of the patients in the hemorrhage group have a CT scan within 1 week of the bleed. Extension of hemorrhage into the ventricular system as seen in eight cases was invariably accompanied by severe neurological dysfunction. A high-density lesion without associated mass effect was found in 48% of patients presenting with a seizure disorder. Dilatation of the ipsilateral lateral ventricle, a common finding in this group of patients, was thought to indicate an atrophic process. Evidence of discrete brain infarction was unusual. Intravenous infusion with Hypaque provided additional information in 31 of the 35 patients so studied. Demonstration of prominent or enlarged feeding arteries and/or draining veins occurred in 20% of patients with large malformations. Six cases of angiographically occult AVM's were found. A correlation of the CT scan with clinical, angiographic, and histological findings is presented.

Adolescent↗
PubMed1978

Cerebellar hemorrhage in adults. Diagnosis by computerized tomography.

A series of 10 adult patients with cerebellar hemorrhage diagnosed by computerized tomography (CT) is described. Hypertension was the most common etiological factor, accounting for 70% of the cases. The clinical presentation appeared to fall into two basic groups. The first group (60% of the cases) ran a progressive course with early brain-stem compression. The second group had a benign course with findings of focal cerebellar dysfunction. The CT findings reflected the two clinical categories. The scans of Group 1 patients revealed a lorge hematoma (greater to or equal to 3cm) and substantial ventricular dilatation. In contrast, scans of Group 2 patients demonstrated a small hematoma (less than 3 cm) without ventricular dilatation. Use of CT scanning allowed the accurate diffferentiation of cerebellar hemorrhage from primary brain-stem and intraventricular hemorrhage. The findings of the CT investigations proved very helpful in defining appropriate therapy.

Adult↗
PubMed1977

Computed tomography in intracranial arteriovenous malformations.

22 patients with proved intracranial arteriovenous malformations (AVM) were studied by computed tomography (CT). Of these, 18 were also studied by CT after intravenous injection of contrast material. The plain scan was normal in 23% of cases. A combination of plain and contrast-enhancement CT proved to be superior to other screening techniques in patients with a possible intracranial AVM.

Humans↗
PubMed1977

Computed tomography in the evaluation of intracranial aneurysms and subarachnoid hemorrhage.

Computed tomography (CT) is a reliable technique for examining patients with subarachnoid hemorrhage and intracranial aneurysms. Extravasated blood is easily recognized and the location of the ruptured aneurysm may frequently be predicted by its distribution into the subarachnoid spaces and brain parenchyma. CT alleviates the need for repeat angiography while following the patient's clinical evolution since it clearly shows rebleed, edema follwoing vasospasm, and hydrocephalus.

Female↗
PubMed1977

Computerized tomography as a possible aid to histological grading of supratentorial gliomas.

Computerized tomography (CT) is known to be very helpful in demostrating the presence and extent of supratentorial gliomas, practically in combination with intravenous injection of contrast material. Certain specific density patterns were found to exist and enabled us to differentiate with confidence the low-grade gliomas from the glioblastomas. Overlapping did occur, however, as was to be expected, since histological proof was sometimes obtained by the needle biopsy with its inherent doubt as to true tumor representation. Future CT techniques such as sequential scanning after intravenous injection of contrast material may further increase the usefulness of CT scans in the diagnosis and therapeutic approach to the patient with a suspected glioma.

Brain↗
PubMed1977

Intraventricular hemorrhage in adults.

A series of 54 adult patients with intraventricular hemorrhage diagnosed by computed tomography (CT scan) is described. Hypertension, arterial aneurysm, and arteriovenous malformation (AVM) accounted for 83% of the cases. Three categories of clinical presentation are defined. CT scan reliably demonstrated the presence and distribution of blood within the ventricular system, including the third and fourth ventricles. The increased density caused by intraventricular blood was seen to disappear in 12 days. An intracerebral hematoma was identified in 78% of cases. Surgical treatment was beneficial in only a small number of cases.

Adult↗
PubMed1977

A syndrome of early recognition of occult hydrocephalus and cerebral atrophy.

A clinical and neuropsychological syndrome for early recognition of occult hydrocephalus and cerebral atrophy is described. Five illustrative patients are reported. The main features of the syndrome are (i) subjective non-specific complaints (headaches, depression and loss of memory); (ii) the tonic foot response of the sole and the grasp reflex of the foot in the absence of the grasp reflex of the hand; (iii) attacks of sudden and transient loss of muscle tone in both lower limbs leading to falls without warning while standing or while walking. These attacks indistinguishable from drop-attacks are termed chalastic fits; (iv) a dissociation between the satisfactory performances on the Ottawa-Wechsler scale and the poor performances on Kohs Block Design test. Clinical and neuropsychological findings could not differentiate between occult hydrocephalus and cerebral atrophy; only radionuclide cisternography and computerized tomography were able to delineate the final diagnosis.

Aged↗
PubMedDate not supplied

Spinal cord paralysis following sclerotherapy for esophageal varices.

A child with cryptogenic cirrhosis underwent a third session of elective sclerotherapy. Endoscopic therapy consisted of intravascular injection of ethanolamine oleate in varices newly developed at the midesophagus level. Irreversible paraplegia was documented within 8 hr postoperatively. Two years later she eventually died from gastrointestinal bleeding. Autopsy findings were compatible with an infarct of the spinal cord secondary to an occlusion of the anterior spinal artery. Various hypotheses which might explain the passage of the sclerosing material from the esophagus to the anterior spinal artery include: arterial occlusion secondary to venous thrombosis and spinal cord necrosis, accidental injection in an intercostal artery or azygous vein through the esophageal wall, the presence of a congenital arteriovenous fistula or the opening of arteriovenous shunt. Paravasal injection of dilute sclerosing agent might protect against this unusual but dramatic complication.

Arteries↗
PubMedDate not supplied

Diatrizoate in computed cranial tomography: a quantitative study.

Plasma diatrizoate concentrations during computed cranial tomography were measured by UV spectrophotometry in 14 patients. A loading dose of 0.82 mg diatrizoate/kg followed by a stead infusion of 0.01 mg/kg was required to attain and maintain plasma concentrations of approximately 400 mg/100 ml. Lowering the beam energy resulted in a substantial increase in the EMI numbers of diatrizoate and significant improvement in the delineation of contrast containing lesions. A contrast index estimating the volume of pixel containing diatrizoate was calculated for five diagnosed lesions and this factor appears to be related to vascularity and extravasation.

Adenocarcinoma↗
PubMedDate not supplied

Proportional localization system for anatomical interpretation of cerebral computed tomograms.

The existence of individual variations in size and shape of the human brain constitutes a problem for the anatomical interpretation of brain reconstructed images obtained from scanning devices; it is, for example, responsible for most of the inaccuracies in reading CT scans. One way to account for these variations is to use a proportional localization system. In the 1960s a group of neurosurgeons developed such a system based on two pivotal intracerebral structures, the anterior and the posterior commissures; they published an atlas consisting of horizontal, coronal, and sagittal brain sections interpreted in the proportional system. The atlas also included standard proportional brain schemes based on anatomical and radiological studies on large numbers of individuals. In this article we report a target localization experiment that we carried out to determine if this atlas could be used as a reference for a more accurate interpretation of CT and, eventually, of positron emission tomography (PET) and nuclear magnetic resonance (NMR) scans. Ten radiopaque small targets were inserted through the skull in the cortex of three cadavers; head CT was performed, and the atlas was used for predicting the cortical location of the targets seen on the CT images: The predictions were confirmed. These results strongly support the use of the proportional atlas for the interpretation of CT as well as of PET and NMR scans.

Anatomy, Artistic↗