[Anatomic variants of Meckel's cave on MRI]. / Variantes anatomiques du cavum de Meckel en IRM.

Magnetic resonance imaging (MRI) gives an accurate analysis of Meckel's cave variability. Images were acquired in 50 patients with several sections for anatomical comparison. Using several sections, MRI is a suitable method for better analysis of the trigeminal cistern. The most frequent findings are symmetrical trigeminal cisterns. Expansion of Meckel's cave or its disappearance has pathological significance.

[Spinal subdural hematoma. Presentation of 2 cases studied with MRI]. / Hématomes sous-duraux rachidiens. Présentation de deux cas explorés en IRM.

Spinal subdural hematomas are rare. They should be considered in the diagnosis of spinal cord compression. Prompt surgical treatment, if it is performed, may lead to complete recovery of the neurological deficit. But such treatment is not always necessary because of possible spontaneous recovery. MRI appears to be the method of choice to reveal hematomas even of small size and to follow up patients after treatment.

[MRI of normal spinal epidural fat]. / IRM de la graisse épidurale rachidienne normale.

The authors perform a retrospective study of 65 spines examined with MRI. They specify the distribution of normal posterior epidural fat and establish the relationship between the anteroposterior thickness of epidural fat and the sagittal diameter of the spine on axial sections. On sagittal sections, the fat has a variable appearance, but a constant location along the spinal canal.

[MRI of the spinal epidural fat in pathology]. / IRM de la graisse épidurale rachidienne en pathologie.

The authors report about their experience with the merits of the normal systematization of epidural fat with MRI. On sagittal sections, this fat has a variable appearance, but its location along the spinal canal is constant. On axial sections, its morphology is suggestive of the level of section: cervical, upper or lower thoracic, lumbar. Some changes in this fat are precious data to explain local hypertrophy (scoliosis) or to locate an intra- or extradural process.

[MRI of malformative syringomyelia. Descriptive and developmental aspect]. / IRM des syringomyélies malformatives. Aspect descriptif et évolutif.

132 cases of malformative syringomyelia have been studied at the C.I.E.R.M. (Interdepartmental Magnetic Resonance Center) of Bicêtre Hospital. The authors describe their technique for the exploration on the cord in case of suspected intramedullary cavitation, and emphasize the morphological and evolutive aspects of these abnormalities, whether they have been operated or not.

[Ultrasonic diagnosis of renal lymphoma in children. A series of 18 cases]. / Diagnostic échotomographique des lymphomes rénaux chez l'enfant. Une série de 18 cas.

Ultrasound tomography imaging is a very effective diagnostic examination for lymphoma of the kidneys, organs which are frequently the site of these tumors (51,5% of cases). A total of 18 cases of renal lymphoma explored by ultrasound tomography over the last 2 years were reviewed, the first patients seen in this series also undergoing intravenous urography and two others a CT scan. In most cases diagnosis from ultrasound imaging was based on findings typical of renal lymphoma and on the almost constant detection of other parenchymatous localizations (liver, spleen, pancreas) or lymph node and/or serous lesions. Tumors were bilateral in 13 cases and unilateral in 5. Ultrasound images showed: a) nephromegaly that was usually bilateral (9 cases) or sometimes unilateral (2 cases), while the kidney or kidneys were of normal size in 4 patients; b) the almost constant presence of hypoechogenic nodules scattered throughout the kidney or kidneys (16 cases); c) global hypoechogenicity of the kidney or kidneys (3 cases)--a sign not reported it the literature--; d) hydronephrosis that was either isolated (2 cases) or associated with the renal lymphomatous lesion (3 cases). The diagnostic reliability, cost and safety of ultrasound imaging make in the examination of choice for the exploration of this affection.