Triple-dose contrast/magnetization transfer suppressed imaging of 'non-enhancing' brain gliomas

Purpose. Triple-dose (TD) gadolinium contrast administration and magnetization transfer suppression (MTS) in brain magnetic resonance imaging (MRI) have proven to be useful for demonstrating additional enhancing lesions in some diseases. The purpose of this study was to determine if there is a subset of brain tumors that demonstrate contrast enhancement with TD and MTS that do not enhance with standard imaging and standard contrast dose. Materials and methods. Fifteen patients with either newly diagnosed primary brain tumor or brain tumor that had been followed for more than 2 years were enrolled. T1-weighted MTS images without IV contrast, with 0.1 mmol/kg without MTS (single-dose (SD) images), and with additional 0.2 mmol/kg gadolinium and MTS ('TD/MTS') were obtained. Results. None of the patients had enhancement on SD images. Six patients had areas of enhancement on TD/MTS images ('exact' chi-squared p = 0.017). Conclusion. A statistically significant increased rate of contrast enhancement was found on TD/MTS images in patients whose tumors did not enhance at single dose without MTS. It is possible that small areas of enhancement seen only with TD/MTS might represent areas of higher-grade tumor.