In vivo high-resolution MR imaging of the carpal tunnel at 8.0 tesla

Objective: To determine the feasibility of acquiring in vivo images of the human carpal tunnel at 8 tesla (T). Design: The wrist of an asymptomatic volunteer was imaged with an 8 T /80 cm magnet. The subject was imaged prone with the arm over the head and the wrist placed in neutral position in a custom-built dedicated shielded wrist coil. Axial two-dimensional gradient-echo (GRE) images of the wrist were acquired. Results: Image contrast and resolution at 8 T are excellent. The infrastructure of the median nerve, particularly the interfascicular epineurium and individual fascicles, is better visualized at 8 T than at 1.5 T. The flexor tendons are well delineated from each other and the surrounding soft tissues, and tertiary tendon fiber bundles are resolved. The boundaries of the carpal tunnel are better defined at 8 T. Conclusion: We have obtained the first high-quality in vivo images of the human carpal tunnel at 8 T. The 8 T images demonstrated better contrast and resolution than those obtained at 1.5 T.