[Hilar adenopathy compressing the pulmonary arteries in the course of sarcoidosis]. / Adénopathies hilaires compressives sur les artères pulmonaires au cours d'une sarcoïdose.

INTRODUCTION: In pulmonary sarcoidosis, vascular involvement is usually limited to the small and medium-sized vessels. Enlarged hilar lymph nodes are usually considered to be soft and hence unlikely to cause pressure on adjacent bronchi or blood vessels. CASE REPORT: We report a rare symptomatic compression of a major pulmonary artery by lymphadenopathy in a case of sarcoidosis. Our patient presented with exertional dyspnoea, with enlarged hilar lymph nodes responsible for segmental pulmonary arterial hypertension, without other thoracic abnormalities. The symptoms and lymphadenopathy regressed with corticosteroid therapy. CONCLUSION: Enlarged hilar lymph nodes can compress major pulmonary arteries and cause segmental pulmonary hypertension. The prognosis can be grave in the absence of treatment.

[Diffusion tensor MR imaging of the brain. Clinical applications]. / Imagerie en tenseur de diffusion et système nerveux central. Pour quelles applications cliniques?

Diffusion tensor MR imaging is a technique that provides details on tIssue microstructure and organization well beyond the usual image resolution. With diffusion tensor MR imaging, diffusion anisotropy can be quantified and subtle white matter changes not normally seen on conventional MRI can be detected. The purpose of this article is to review the current applications of diffusion tensor MR imaging for the study of the brain, including normal aging, Alzheimer's disease, neuropsychiatric disorders, strokes, multiple sclerosis, brain tumors and intractable seizures.