Contrast-enhanced Magnetic Resonance Imaging of Brain Metastases at 7.0T versus 1.5T: A Preliminary Result

Abstract

Purpose: To compare the depiction of brain metastases on contrast-enhanced imageswith 7.0 tesla (T) and at 1.5T MRI. Materials and Methods: Four consecutive patients with brain metastases werescanned on 7.0T whole-body scanner and 1.5T MRI. A 3D T1-weighted gradient echosequence (3D T1-GRE) at 1.5T (voxel size = 0.9 × 0.9 × 1.5 mm3 after double-dose,gadoterate meglumine, Gd-DOTA) was compared to a 7.0T 3D T1-GRE sequence(voxel size = 0.4 × 0.4 × 0.8 mm3, single-dose Gd-DOTA) in four patients after a 5minute delay. The number of contrast-enhancing metastases in MPRAGE images wascompared in each patient by two radiologists in consensus. We measured contrastratio of enhancing brain metastases and white matter in 1.5T and 7.0T. Results: In all four patients 7.0T 3D T1-GRE images after single-dose Gd-DOTAand 1.5T after double-dose Gd-DOTA depicted 11 brain metastases equally. In thequantitative analysis of contrast ratios of enhancing brain metastases and whitematter, the 1.5T 3D T1-GRE after double-dose showed an increased contrast ratiocompared to 7.0T 3D T1-GRE after single-dose (0.961 ± 0.571 versus 0.885 ± 0.494; n= 11 metastases). But this difference was not statistically significant (P = 0.711). Conclusion: Our preliminary results indicate that 7.0T single-dose Gd-enhancedimages were not different to 1.5T double-dose Gd-enhanced images for the detectionof brain metastases.