A guidewire insertion tool configured to measure a length of an anatomic region. The tool can include a housing, a light chamber, and a track at least partially extending through the light chamber. The track is adapted to guide a guidewire as it is advanced through the insertion tool. The tool can also include an optical sensor assembly in optical communication with the light chamber. The optical sensor assembly can include one or more light sources, an optical sensor, and a magnifier. The one or more light sources can be adapted to direct light toward a portion of the guidewire within the track, and the optical sensor can be adapted to receive reflected light from the portion of the guidewire within the tract. A processing unit can analyze data from the optical sensor assembly to determine the length of the anatomic region and output the measurement to a display.