[Principles of medical liability and practice in medical imaging]. / Principes de responsabilité médicale et exercice en imagerie médicale.

Radiologists are liable for all aspects of their practice, from the indication of an examination to the radiology report and follow-up, as well as for providing information and recommendations. They are liable for their decisions and actions. They are liable for their competence and continuous medical education. They are also liable for their own equipment and staff. In cases of litigation, the liability of a radiologist may be questioned. Four types of procedures must been known: penal, civil, administrative and disciplinary.

Minimal surface: a useful paradigm to describe the deeper part of the corpus callosum?

The aim of this magnetic resonance imaging study was to find a geometrical characterization of the deeper part of the corpus callosum. Its shape was studied in 12 middle-aged persons free of white matter pathology. Profiles of curvatures were measured showing that this surface was close to a minimal one, especially at the genu and near the splenium. To assess the effect of a white matter pathology on these geometrical features, the same measurements were performed in an extra group of nine patients with definite multiple sclerosis. The hypothesis of curvatures profiles parallelism for the two groups could be rejected at the 0.05 confidence level for the mean curvatures but not for the Gaussian ones. Curvatures profiles may give indications on balance between the cortex and the fiber bundles growth rates during the development and on large scale modifications co-occurring with multilocular white matter pathologies.

A prospective study of patients with CT detected pallidal calcifications.

In a prospective study pallidal calcification was detected in 30 of 1478 (2%) adult patients, on CT brain scans. In 8 cases (26%), the calcifications were detected either years after, or during the course of, conditions known to cause basal ganglia calcification, including AIDS in four cases. Eight patients (three with AIDS) had disturbances of calcium and phosphorus metabolism. It was concluded that: a) pallidal calcification is not uncommon and aetiological factors may be recognised more often than previously reported; b) AIDS is emerging as a significant cause of pallidal calcification in young adults, and c) in AIDS and other conditions, abnormal calcium and phosphate metabolism may act in conjunction with local vascular changes.

[Eye movements: initial dynamic approach in high resolution magnetic resonance imaging]. / Mouvements oculaires: première approche dynamique en imagerie par résonance magnétique (I.R.M.) de haute résolution.

New MR softwares allow a dynamic display of different fonctionnal anatomical regions. This work is a first attempt to visualize the ocular movements. A video tape constitute the support of our results. Technically, the work is performed on a Signa 1,5 T GE CGR System. During each MR acquisition, the subject is asked to fix his gaze successively on each spot of a scale set inside the bore of the magnet. Twenty four images are performed to show the entire lateral course of the globes. The examination time is about half an hour. The video display show the movements of agonist and antagonist muscles, the eyeballs and the optic nerves displacements, in the axial neuro-ocular plane (NOP). Different clinical applications of this new method are discussed (muscular surgery...).

[Semi-automated quantification of MRI high signals observed in multiple sclerosis]. / Quantification semi-automatisée des zones de haut signal IRM observées dans la sclérose en plaques.

MR T2 Weighted sequences on the brain demonstrate disseminated "high signal zones" (HSZ) in patients with Multiple Sclerosis; these morphological alterations are corresponding to the plaques. From the very beginnings of MR in 1981, everybody recognizes the main importance of this fact. MR appears as the most sensible exploration in patients with M.S. But the signal alteration is not specific; the clinical considerations and the evolution are requested. The aim of this work is to give a reference tool for evolutive evaluation of the disease. A work station with a specially developed software are presented. The HSZ thresholding is partially automatic. The edition of a cerebral mapping is developed. These results are discussed.

[Lobar holoprosencephaly associated with heterotopic gray matter. A case disclosed in adulthood by epilepsy]. / Holoprosencéphalie lobaire associée à des hétérotopies de substance grise. Un cas révélé à l'âge adulte par une épilepsie.

A case of lobar holoprosencephaly associated with heterotopias of the grey matter is reported. The patient was a young woman whose cerebral malformation was revealed by epileptic seizures at the age of 22. There was no intellectual deficit. Computerized tomography and, chiefly, magnetic resonance imaging, enabled the study of the malformation.

[Results of bromocriptine treatment of giant or invasive prolactin adenomas. Apropos of 20 cases]. / Résultats du traitement par Bromocriptine des adénomes à prolactine géants ou expansifs. A propos de 20 observations.

The therapeutic results of twenty patients with giant expansive prolactinomas were studied under bromocriptine as treatment of first intent (Group I, n = 10) or of second intent after surgery with or without radiotherapy (Group II, n = 10). Patients in Group I (PRL: 350-17 000 ng/ml) were given bromocriptine alone (10 to 20 mg/day) for a period of 21 days to 22 months. The visual fields and acuity returned to normal in 8 days to 3 months in 4 out of 7 patients and significantly improved in 2 out of 7 patients. A reduction in tumour size was demonstrated on CT scanning in 7 out of 10 patients mainly in the suprasellar region (6/9) with appearances of a partially empty sella in 4 cases. Normalisation of the PRL (7 out of 10 cases) was accompanied by a correction of one or more other hypophyseal deficits in 3 patients. Bromocriptine was continued in 5 out of 10 cases with a good result after 12 to 22 months follow-up. Five patients were referred secondarily for surgery for spontaneous rhinorrhea in 1 patient or because Bromocriptine was only partially effective in 4 patients; a postoperative visual improvement with reduced serum prolactin levels was observed in these 4 cases. In Group II (PRL: 200-11 600 ng/ml after surgery), bromocriptine therapy (5 to 30 mg/day for 1.5 to 72 months) was associated with normalisation or a significant improvement in visual symptoms in 6 out of 9 cases and a reduction in tumour size in 8 out of 10 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Myelographic diagnosis of radiculomeningeal metastases of carcinomas. Apropos of 10 cases]. / Diagnostic myélographique des métastases radiculo-méningées des carcinomes. A propos de dix observations.

The authors report ten cases of intra-arachnoid metastases affecting the spinal cord and its roots. These cases illustrate all the myelographic appearances seen: multiple nodular appearances, striated appearance related to thickening of the roots, failure to visualise one or more root sheaths, filling defect of varying regularity preferentially seen in the dural cul-de-sac, but also in the terminal part of the cord associated with varying degrees of block. Myelographic technique is essential of they are to be visualised: water soluble opaque agents and tomography, if possible by complex scanning alone ensure accurate analysis of the roots. This type of involvement raises a pathogenic problem regarding the exact mechanism of such metastases. The prognosis is very poor despite treatment based upon radiotherapy and chemotherapy.