[High dosage administration of paramagnetic contrast media in diagnosis of focal brain lesions]

In analogy with high-dose contrast-enhanced CT, there have been a few studies during recent years that have dealt with high-dose paramagnetic contrast dyes in MRI. One reason for these studies was the development of new and low-osmolar contrast agents in the MR field. Depending on the clinical problem, a high-dose contrast study in MRI is rarely indicated: (1) in metastatic disease, MR imaging with high-dose contrast material is indicated when the standard dose study is negative or only shows a solitary cerebral lesion or a number of lesions just suitable for radiosurgery; (2) in patients with malignant glioma the high-dose study allows better definition of the tumor margins. If a radical surgical approach is planned, the diagnostic potential should be fully used; if only a biopsy or subtotal debulking is planned, a standard dose study is enough. (3) in patients with MS, a high-dose study is only recommended within therapeutic trials in which the number of active plaques is a primary variable.