Time dependence of serial diffusion-weighted imaging features in a case of pyogenic brain abscess.

Both signal intensity on trace images and apparent diffusion coefficient measurements on mapped images evolved rapidly on serial diffusion-weighted sequences in a case of pyogenic brain abscess that was monitored primarily by MRI before a biopsy was performed. Considering only the signal intensities on the trace images would have led to an underestimation of the intrinsic tissue changes.

Pre- and peroperative misdiagnosed sellar tumour.

We describe the case of a 76-year old woman complaining of headaches and progressive sight loss. Cerebral CT scan and MRI disclosed a large sellar tumour. Endocrine evaluation showed no evidence of pituitary hypersecretion, but a slight hyperprolactinemia related to stalk compression.

MR-monitored remitting-relapsing pattern of cortical involvement in Rasmussen syndrome: comparative evaluation of serial MR and PET/SPECT features.

We report the serial MR and PET/SPECT findings in a 2 1/2-year-old boy presenting with Rasmussen syndrome and highlight the close qualitative correlations between the results of the imaging modality and the functional isotopic techniques. The latter demonstrated a wider field of extension of the disease process. Routine MRI demonstrated its ability to detect brain changes matching the more sensitive PET and SPECT data and correlated well with the clinical evolution.

Whipple disease confined to the central nervous system in childhood.

In a case of pediatric Whipple disease confined to the central nervous system, white matter lesions initially appeared as areas of very low signal intensity on T1-weighted MR images and as areas of hyperintensity on proton density-weighted and T2-weighted images, and showed slight peripheral enhancement on delayed contrast-enhanced T1-weighted images. On MR studies obtained 3 and 6 months after antibiotic therapy, the lesions had decreased in size and no longer enhanced. They became progressively less hypointense on T1-weighted images and less hyperintense on T2-weighted images.

Pathogenetic factors in chronic subdural haematoma and causes of recurrence after drainage.

The radiological aspect, pathology, treatment and results of 132 subdural haematomas observed in 100 patients, are discussed. The majority of these cases were characterized by a nonhomogenous CT scan picture, resulting from repeated bleeding in a previous subdural haematoma evolving to chronicity, or in a pre-existent subdural hygroma. Taking aspirin may have constituted a predisposing factor in 16% of our patients, whilst coagulation disturbances, including anticoagulant treatment, were observed in another 6%; ethylism was present in 11%.