A microcoil is manufactured by rolling a trace unit in such a way as to form at least one winding. The trace unit is comprised of a conductive trace attached to a flexible insulating film. A preferred embodiment of the microcoil contains both a first winding and a second winding electrically connected and spaced apart by a joining portion. The microcoil may be used for internal magnetic resonance imaging of patient by attaching the microcoil to a catheter.