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Biomedical subjects

M Gayet-Delacroix

Publications and source records attributed to M Gayet-Delacroix.

10 recordsLinked to original sources

Radiation-induced cancers of the pharynx and larynx: a study of five clinical cases.

Radiation-induced cancer, a rare clinical entity, is often difficult to diagnose and manage. This study reports a series of five cases of radiocarcinogenesis of the pharynx and/or larynx that developed after external radiotherapy. The primary lesion was diagnosed at a mean age of 50 years (+/-12.9) and the radiation-induced cancer at a mean age of 59 years (+/-13.1), giving a latent period of 9 years (+/-3.7). Analysis of gammagraphic records indicated that four of the patients had developed a secondary tumour in the penumbra of irradiation fields. In these zones, the delivered dose was between 20 and 80% of the prescribed dose, corresponding to an estimated cumulative mean dose of 14.1-56.3 Gy. These results are compared with data in the literature to determine the diagnostic criteria for radiation-induced cancer, possible predisposition (genetic or acquired) and the dose effect.

Adult↗

[The foramen rotundum. Anatomy and radiological explorations. Pathology].

The foramen rotundum is a small canal deeply situated in the base of the skull which represents the way of exit of the maxillary nerve, second branch of the trigeminal nerve. Its precise individualization and analyse is difficult and necessitates a precise and adapted technique as well as a precise knowledge of its anatomical relationships. Its represents a frontier area between the endo- and exocranial spaces. Its involvement which is preferentially related with tumoral pathologies (and particularly with retrograde perineural invasion) profoundly modifies the prognosis of the disease and so should allow soon a multidisciplinary therapeutic discussion.

Bone Diseases↗

[Imaging of the cochleo-vestibular system].

This article will review the main pathologies affecting the vestibulocochlear system from the sensorineural organs to the cerebral cortex. MR imaging has greatly improved detection of these pathologies. Thin slice MR imaging using different pulse sequences now allows improved depiction of anatomical structures. Vestibular schwannoma is by far the most common lesion, but MR imaging allows detection and characterization of rarer lesions in patients often presenting with similar symptoms.

Brain Diseases↗

Diagnosis of brain death using two-phase spiral CT.

PURPOSE: The purpose of this study was to determine the utility of spiral CT in the diagnosis of brain death. METHODS: Spiral CT was evaluated prospectively in 14 brain-dead patients and in 11 healthy subjects. A two-phase protocol was used. Twenty seconds after intravenous injection of a nonionic iodinized contrast medium, the CT table was drawn through the gantry at a rate of 10 mm/s while scanning was in progress. The second scanning phase was started automatically a mean of 54 seconds later, using the same parameters. Opacification or absence of opacification of carotid, vertebral, and basilar arteries and intracerebral veins was ascertained for each image in both phases. The diagnosis of brain death was confirmed by elecroencephalography (n = 7), angiography (n = 5), or both (n = 2). Statistical analysis with the Fisher exact test enabled us to compare the brain-dead patients with the healthy control subjects. RESULTS: In brain death, the pericallosal and terminal arteries of the cortex did not opacify during the two phases of spiral CT, whereas the superficial temporal arteries were always visible. The internal cerebral veins, the great cerebral vein, and the straight sinus did not opacify, whereas the superior ophthalmic veins were visible on both sides 13 times. For each vessel type, specificity was 100% for nonvascular opacification criteria on the right and left sides. CONCLUSION: Two-phase spiral CT can demonstrate the absence of intracerebral blood flow in brain death.

Adolescent↗

[The value of beta-2 transferrin analysis and MR cisternography for the diagnosis of cerebrospinal fluid fistulas].

The diagnosis of cerebrospinal fluid (CSF) fistula may require invasive techniques. Detection of CSF and perilymph-specific beta 2 transferrin and MR cisternography which greatly enhances the CSF signal are sensitive and noninvasive techniques which allowed a precise diagnosis in seven patients with suspected CSF fistula. We review the different diagnostic techniques used for CSF fistula, beta 2 transferrin analysis and MR cisternography appear to provide accurate and noninvasive methods for investigating CSF fistulae. They should replace invasive techniques such as CT cisternography.

Adult↗

[Radio-anatomical study of the external auditory canal. Comparison between anatomical pieces and x-ray computed tomography].

Ear canal CT scan is widely used in addition to clinical examination, for diagnosis and evaluation of disease extension. Ear mouldings were performed on 11 cadavers (22 mouldings), 5 measurements were taken on each specimen and compared with CT scan measurement. Moulding measurements varied from side to side in one specimen, and moreover from one specimen on another one. Comparison between mouldings and CT scan showed that medial meatus measurements are identical. On the other hand, there are wide gaps for the lateral measurements. Biometrical disparity of the external auditory canal (EAC) was confirmed by this study. CT scan measurements in the lateral portion of the EAC are not reliable. Quantitative usefulness of CT scan is therefore limited to the study of the bony meatus.

Adult↗

Abdominal MRI using a negative contrast agent.

A dose of 0.5 g of a negative oral contrast agent for labelling the bowel, was given to 40 patients in a clinical trial. Oral magnetic particles (OMP) consist of crystals of iron oxide with superparamagnetic properties, and are administered in 800 ml of a viscous suspension in order to obtain a uniform distribution. The aim of the study was to identify any adverse effects up to 1 week following ingestion, as well as the contrast distribution and effect, together with the induction of artifacts. A comparison of diagnostic value of the pre and postcontrast ingestion series was also performed. Vomiting followed ingestion in a single patient already nauseated and was the only adverse effect. Good contrast distribution and effect with no artifacts were present. The diagnostic information was greatly improved after OMP ingestion, and the diagnosis would not have been possible without the use of the contrast agent in 41% of the examinations.

Abdominal Neoplasms↗

[Arteriography in renal metastases from solid tumors (excluding lymphomas). Study of 3 cases and review of the literature].

Three cases of arteriography of renal metastasis of solid tumors are presented. Twice the primitive cancer was bronchial, once laryngeal. There is not other clinical metastasis at the time of arteriography. A general revue of the 19 observations of the litterature is donemthe indication of the arteriography is justified if the primary tumor is not known or if there is not other metastasis. On the cortrary if they are diffused, the indications of this angiography are obviously very limited. In six cases, one can see, as in our observation, stretched thin, encased arteries with a lacune at the nephrographic time. In six other, at these images, are associated rare flecks and neovascularisations; Theses radiological syndromes seem to us characteristic. More rarely the angiography may be normal (3 cases) or look like a primitive renal tumor (3 cases). We must say, however, that nearly all the observations have anatomicaly a renal tumor. The other types of renal metastasis are not well known angiographycally.

Adult↗

The petrosquamosal sinus: CT and MR findings of a rare emissary vein.

BACKGROUND AND PURPOSE: Morphologic changes in the dural sinuses and emissary veins of the posterior fossa relate closely to the development of the brain. We report characteristic findings of imaging in six patients with a rare and forgotten emissary vein called the petrosquamosal sinus (PSS). METHODS: From a larger group of patients with ear abnormalities, we selected six patients from three ENT imaging centers, because they had CT features suggestive of a PPS. This was the criterion for inclusion in this retrospective study. They were explored by high-resolution CT (HRCT) of the temporal bone. MR venography was performed in three patients to determine the presence and patency of the emissary vein. RESULTS: The PPS was bilateral in two patients and unilateral in the other four. It affected mainly the left side (left:right ratio, 5:3). Three patients had associated inner ear (n = 2) or middle ear malformations (n = 1). Five of six patients had jugular vein hypoplasia, with development of emissary mastoid veins in three patients. CONCLUSION: Petrosquamosal sinus can be identified on HRCT in a typical location. It is encountered more frequently in patients referred for congenital abnormalities of the skull base. This rare anatomic variant should be assessed before surgical treatment, because proper identification of these large venous channels would be of interest to the surgeon.

Abnormalities, Multiple↗