Limited MRI of the brain as an alternative to CT.

摘要

The suggestion by Diego Martin and Richard Semelka (May 27, p 1712)1 to decrease the use of CT, where possible, ought to be given serious attention by everyone involved in patients' care. On an individual basis, although the benefits substantially outweigh the risk from the small amount of radiation involved with a CT scan, when extrapolated to a large growing population being imaged with CT, the trend points to a long-term public-health concern.To assess intracranial pathology, a CT scan of the head is usually done instead of MRI owing to cost considerations. However, a limited MRI with Tl-weighted, T2-weighted, and diffusion-weighted images (with apparent diffusion coefficient mapping), could substantially decrease the duration and cost of the procedure. Such a limited MRI would yield better results than a CT, and a further MRI might be obviated.Although the brain was once considered relatively radioresistant, recent data suggest that it is in fact radiosensitive, especially in childhood.High-dose cranial irradiation has been shown to be associated with cognitive decline.