Intracranial microvascular imaging at 7 T MRI with transceiver RF coils

Abstract

PurposeTo investigate intracranial microvascular images with transceiver radio-frequency (RF) coils at ultra-high field 7T magnetic resonance imaging (MRI). Materials and methodsWe designed several types of RF coils for the study of 7T magnetic resonance angiography and analyzed quantitatively each coil's performance in terms of the signal-to-noise ratio (SNR) profiles to evaluate the usefulness of RF coils for microvascular imaging applications. We also obtained the microvascular images with different resolutions and parallel imaging technique. ResultsThe overlapped 6-channel (ch) transceiver coil exhibited the highest performance for angiographic imaging. Although other multi-channel coils, such as 4- or 8-ch, were also suitable for fast imaging, these coils performed poorly in homogeneity or SNR for angiographic imaging. Furthermore, the 8-ch coil was poor in SNR at the center of the brain, while it had the highest SNR at the periphery. ConclusionThe present study has demonstrated that the overlapped 6-ch coil with large-size loop coils provided the best performance for microvascular imaging or angiography with the ultra-high-field 7T MRI, mainly because of its long penetration depth together with high SNR.