In vivo MRI of the human finger at 7 T

Abstract

Purpose: To demonstrate a dedicated setup for ultrahigh resolution MR imaging of the human finger in vivo.

Methods: A radiofrequency coil was designed for optimized signal homogeneity and sensitivity in the finger at ultrahigh magnetic field strength (7 T), providing high measurement sensitivity. Imaging sequences (2D turbo-spin echo (TSE) and 3D magnetization-prepared rapid acquisition gradient echo (MPRAGE)) were adapted for high spatial resolution and good contrast of different tissues in the finger, while keeping acquisition time below 10 minutes. Data was postprocessed to display finger structures in three dimensions.

Results: 3D MPRAGE data with isotropic resolution of 200 µm, along with 2D TSE images with in-plane resolutions of 58 × 78 µm² and 100 × 97 µm² , allowed clear identification of various anatomical features such as bone and bone marrow, tendons and annular ligaments, cartilage, arteries and veins, nerves, and Pacinian corpuscles.

Conclusion: Using this dedicated finger coil at 7 T, together with adapted acquisition sequences, it is possible to depict the internal structures of the human finger in vivo within patient-compatible measurement time. It may serve as a tool for diagnosis and treatment monitoring in pathologies ranging from inflammatory or erosive joint diseases to injuries of tendons and ligaments to nervous or vascular disorders in the finger. Magn Reson Med 79:588-592, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Keywords: 3D visualization; MR microscopy; MRI; Pacinian corpuscle; RF coil; human finger; ligaments; solenoid; tendons; ultrahigh field; vasculature.