An MRI-guided medical device includes an elongated sheath, an elongated dilator, and an elongated needle. The sheath has a distal end, an opposite proximal end, and a central lumen extending between the proximal and distal ends. The sheath comprises MRI-compatible material and includes a tracking member located adjacent to the sheath distal end that is visible in an MRI image. The dilator comprises MRI-compatible material and is movably disposed within the sheath lumen. A distal end of the dilator is configured to extend outwardly from the sheath distal end and dilator includes at least one tracking member that is visible in an MRI image. The needle is movably disposed within the dilator lumen and is movable between stored and operative positions relative to the dilator. An RF shield may be coaxially disposed within the elongated sheath so as to surround a portion of the sheath central lumen.