Fig. 7.

Technique of marking skin entry using grid method.

A. Axial CT image of 60-year-old man showing infiltrative mass. Skin entry site selected on CT console and its location was noted in relation to superimposed grid lines. B. Firstly, axial level was marked by moving patient in CT gantry at same table position. C. Lateral distance is measured from midline laser light in alignment with central grid line. D. After marking skin entry site, impression was made over skin by pressing back of needle hub (arrow), since it remains visible even if ink is erased during cleaning process.