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Biomedical subjects

G Marchal

Publications and source records attributed to G Marchal.

At least 307 records · Page 17Linked to original sources
PubMed1989

[Computed tomography and magnetic resonance imaging in anomalies of neuronal migration].

This is a report of the CAT-scan and MRI characteristics in 14 patients with anomalies of neuronal migration. There were 3 cases of heterotopia of the gray matter, 2 cases of agyria, 3 cases of pachygyria, 2 cases of schizencephaly and 4 cases of hemimegalencephaly. The primary advantages of MRI in comparison with CAT-scanning, are better contrast between the white and gray matter; better delineation of the cerebral cortex and the possibility of direct mutiplanar imaging. NMRI will become the investigation of choice in children with epilepsy or psychomotor retardation.

Adolescent↗
PubMed1989

[Spontaneous dissection of the cervical internal carotid artery. Diagnosis by MRI].

A case of spontaneous dissection of the cervical internal carotid artery documented by angiography and MRI is reported. Angiography showed an irregular stenosis of the upper part of the cervical internal carotid artery extending up to the base of the skull, suggestive of spontaneous dissection. The diagnosis was confirmed beyond doubt by MRI which showed a sub-intimal collection of blood with a typical hyperintense appearance.

Aged↗
PubMed1989

MR imaging of the brain: preliminary results with a gradient echo sequence after paramagnetic contrast enhancement.

In a series of 15 patients with contrast enhancing lesions of the brain, a gradient echo sequence (TR = 400 ms; TE = 10 ms; flip angle 90 degrees, one excitation) after IV administration of a paramagnetic contrast agent provided equal diagnostic information and image quality to conventional T1 weighted spin-echo images. Imaging time for one sequence could be reduced by two thirds to 1 min 45 sec. Susceptibility artifacts caused only slight image degradation in the bitemporal region and the region of the sella turcica. This gradient echo sequence can be useful in combination with paramagnetic contrast enhancement, as a complement to conventional T1 and T2 weighted spin-echo sequences.

Brain Diseases↗
PubMed1989

Magnetic resonance imaging in acoustic neurinoma. Comparison with CT.

MRI and CT were performed in 16 patients with 17 acoustic neurinomas. MRI was superior to CT in the detection of small acoustic neurinomas, in the demonstration of intracanalicular extension and in the differentiation with cerebellopontine angle meningiomas. Overall advantages of MRI over CT included better tissue contrast, absence of bone artifacts and easy multiplanar imaging.

Adult↗
PubMed1989

Magnetic resonance imaging in lesions of the eye globe.

Magnetic Resonance Imaging (MRI) findings in 22 patients with lesions of the globe were examined. There were 16 cases of malignant uveal melanoma, 2 cases of retinoblastoma, 3 cases of hemorrhagic choroidal detachment and 1 case of senile macula degeneration. MRI adequately depicted the lesions in 20 cases. In two cases MRI findings were unconclusive due to movement artifacts of the eye globe. Fourteen out of 16 uveal melanomas displayed typical T1 and T2 shortening. In the two other cases the hypointense aspect on T2-weighted images was less pronounced due to a lesser amount of melanin in the lesions as demonstrated by subsequent histology. Unlike with CT, the tumoral lesions could clearly be differentiated from subretinal exudate. The case of senile macula degeneration, two retinoblastomas and two cases of hemorrhagic choroidal detachment had the same MRI characteristics as melanomas.

Adult↗
PubMed1989

Biliary ascariasis.

A patient with biliary ascariasis was observed. The diagnosis was strongly suggested on endoscopic cholangiography. X-ray examination of the small bowel confirmed intestinal infestation and the stools were positive for ascaris lumbricoides. The incidence, symptomatology, diagnostic features, complications and therapy of biliary ascariasis are briefly discussed.

Adult↗
PubMed1988

Early influx of Listeria-reactive T lymphocytes in liver of mice genetically resistant to listeriosis.

Murine listeriosis is a classical model for investigating mechanisms of cellular immunity, which involves interaction of macrophages and T lymphocytes. The early course of this experimental infection is under control of a limited number of genes in the murine host. In the present study, we asked whether the early efficient control of bacterial growth in the liver of resistant mice is related to the expression of a more rapid specific immune response in this organ than in susceptible mice. Therefore, we compared the frequencies of Listeria monocytogenes-reactive T cells in blood, spleen, and liver of resistant C57BL/6 and susceptible C3H/He Past mice after i.v. injection of a high dose of Listeria (9 x 10(5) CFU). T cells were titrated through their ability to locally transfer a delayed-type hypersensitivity reaction to viable L. monocytogenes, an effector function potentially relevant to the early step of protective mechanisms. We observed (1) a 9- and 4-fold increase by day 1 in the frequency of Listeria-reactive transfer units in the blood of C57BL/6 and C3H mice, respectively, (2) no increase in the number of Listeria-reactive transfer units in the spleen of 2-day infected mice of both strains, and (3) a 90-fold increase, at day 2, in the number of Listeria-reactive transfer units in the liver of resistant C57BL/6 compared with only a 9-fold increase in the liver of susceptible C3H/He. These results suggest that the ability of C57BL/6 mice to control the early bacterial growth (0 to 48 h) in their liver, may be related to a rapid influx of L. monocytogenes-reactive T lymphocytes.

Animals↗
PubMed1988

Intravenous digital subtraction angiography and Duplex scanning in the detection of late human umbilical vein degeneration.

To define the exact incidence of late degeneration, 32 patients underwent intravenous digital subtraction angiography (IVDSA) and/or a Duplex scan more than 3 years after human umbilical vein (HUV) grafting. IVDSA (n = 26) showed a 23 per cent aneurysmal degeneration rate which increased to 40 per cent with Duplex scanning (n = 25). Although the differences obtained in those patients receiving both examinations (n = 19) were statistically not significant, Duplex scanning appeared to be more sensitive, demonstrating two additional cases of aneurysmal degeneration not detected by IVDSA. Since, moreover, Duplex scanning proved able to detect anastomotic stenosis, it appears to be the examination of choice in long-term follow-up of the HUV graft. Despite this relatively high degeneration rate, the authors consider continued use of the HUV graft in selected patients to be justified, especially when the long-term patency rates, the available alternatives, and the less favourable long-term survival after femoropopliteal reconstruction are taken into consideration.

Aneurysm↗
PubMed1988

Surface coil magnetic resonance imaging of the orbit at 1.5T.

MRI of the orbit at 1.5-Tesla was performed in 5 healthy volunteers and 30 patients with a variety of pathological intraocular or intraconal conditions. Major advantages of MRI over CT include higher spatial resolution, higher tissue contrast, possibility of direct multiplanar imaging, absence of bony and dental artifacts, and of ionising radiation. Specific indications of MRI in orbital pathology concern differentiation of uveal melanoma from subretinal haemorrhage, identification of lesions of the orbital apex, the orbital fissure or the optic canal, differentiation of inflammatory pseudotumour from malignant lesions, determination of the posterior extension of lesions of the optic nerve, and detection of abnormal flow in normal or hypertrophic intraorbital vessels. Limitations are due to motion artifacts on T2 weighted sequences, less accurate visualisation of calcification, poor specificity of some findings, and absence of signal from cortical bone.

Cranial Nerve Neoplasms↗
PubMed1988

The effect of blood transfusion on cerebral blood-flow in preterm infants: a Doppler study.

Stable infants with anaemia needing a transfusion with adult red blood-cells were studied to elucidate changes in brain blood-flow velocity. Within 24 hours and at five to six days following transfusion a substantial mean flow velocity reduction was observed. Haemodynamic factors contributing to the reduction were an increase in cerebrovascular resistance and an increase in whole blood viscosity, as reflected by a raised pulsatility index. Transfusion with adult red blood-cells causes an elevation in haemoglobin concentration, thereby increasing the total oxygen-carrying capacity of arterial blood; however, this lowers the concentration of fetal haemoglobin which possesses a higher affinity for oxygen. Since cerebral oxygen transport is equal to the product of cerebral blood-flow and arterial oxygen content, this finding suggests the existence of a homeostatic mechanism for cerebral oxygen transport. The actual amount of cerebral oxygen transport was found to increase progressively as the percentage of fetal haemoglobin rose above 30 per cent. At higher fetal haemoglobin levels, appropriate elevations in cerebral blood-flow occurred, causing an increase in the supply of oxygen to the brain.

Blood Flow Velocity↗
PubMed1988

Staging and follow-up of rheumatoid arthritis of the knee. Comparison of sonography, thermography, and clinical assessment.

Twenty patients with longstanding polyarticular rheumatoid arthritis (including knee involvement) were selected for this study. The severity of the knee synovitis was assessed before and during treatment (with intra-articular corticosteroid injections) using clinical scores, sonography, and thermography. In all patients, the inflammation regressed during treatment. During follow-up, the quantity of synovial fluid, as measured sonographically 10 days after the start of therapy, correlated best with the clinical status. Maximal regression of synovial thickening was noted on delayed sonograms performed three months after treatment. Thermographic peak temperature showed good correlation with the clinical status, but the thermographic index was unreliable.

Adrenal Cortex Hormones↗