HIGH-DOSE CONTRAST STUDY USING PARAMETRIC CONTRAST AGENTS IN THE 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 paramagneti c contrast dyes in MRI. One reason for these studies was the developme nt of new and low-osmolar contrast agents in the MR field. Depending o n the clinical problem, a high-dose contrast study in MRI is rarely in dicated: (1) in metastatic disease, MR imaging with high-dose contrast material is indicated when the standard dose study is negative or onl y shows a solitary cerebral lesion or a number of lesions just suitabl e for radiosurgery; (2) in patients with malignant glioma the high-dos e study allows better definition of the tumor margins. If a radical su rgical approach is planned, the diagnostic potential should be fully u sed; if only a biopsy or subtotal debulking is planned, a standard dos e study is enough. (3) in patients with MS, a high-dose study is only recommended within therapeutic trials in which the number of active pl aques is a primary variable.