Evaluation of Skull Base Tumors with Dynamic TurboFLASH MRI during Gadolinium Injection.

Background and Purpose  This study was aimed to investigate the role of dynamic TurboFLASH gadolinium (Gd) magnetic resonance (MR) imaging in improving the differential diagnosis of skull base tumors. Methods  Eleven patients with skull base tumors underwent standard MR and ultrafast TurboFLASH sequence during gadolinium injection. Results  The characterization of tumor vascularity was performed. Different patterns of gadolinium uptake for each tumor type were observed. This is particularly important to identify tumors at high risk of intraoperative bleeding. All glomus tumors, typically highly vascularized, showed an enhancement at the arterial phase, reflecting the arterialization of these tumors which is not detectable on conventional MR. No signal increase at the arterial phase was instead observed in other cases in which the ruling out of a glomus tumor was important because of the location of the lesion. Moreover TurboFLASH identified the pathognomonic "filling-in" profile of cavernous sinus cavernous hemangiomas (CSCH), that is, the progressive centripetal enhancement of the lesion at the beginning of the venous phase. Conclusion  The dynamic analysis of tumor contrast enhancement with the TurboFLASH sequence provides useful additional information to that obtained with conventional MR, improving the differential diagnosis of skull base tumors, particularly in the distinction between glomus and nonglomus tumors and in diagnosing CSCH.