MR imaging of CNS tumors: are all contrast agents created the same?

The challenging and multiple goals and requirements of CNS tumor imaging require optimization of the CNS imaging protocols, including selection of the optimal contrast medium. There are several gadolinium compounds available for imaging the CNS, and all of these except the compound Gd-BOPTA have nearly identical profiles. The unique protein interaction of Gd-BOPTA results in double T1 and T2 relaxivity. This article summarizes the advantages of Gd-BOPTA over conventional gadolinium compounds in both conventional and functional MR imaging. The results of recent studies in adults and pediatric patients are presented and discussed. The principal conclusion of this article is that not all contrast agents approved for MR imaging of the CNS behave in the same way. The use of the high-relaxivity agent Gd-BOPTA for morphological and functional MR imaging allows improved detection and delineation of CNS lesions compared to conventional gadolinium agents. This not only permits more confident diagnoses, but also results in a substantially improved differential diagnostic process. The higher relaxivity of Gd-BOPTA helps to optimize functional MR imaging studies e.g. perfusion MR imaging and other dynamic MR imaging protocols.