Fig. 1

Percutaneous access marking for CTF-guided lung ablation. a Preprocedural CT of a patient scheduled for treatment by image-guided percutaneous lung ablation of a single lung colon cancer metastasis located in the left upper lobe (arrow). Note that the CT scan was performed in the position chosen to perform the procedure (prone). b Marking of the lesion with a radiopaque grid (triangle). The scanner parameters were modified to decrease the exposure to ionizing radiation of the operator and the patient. Hence the decreased image quality. c Example of the marking procedure. The vertical axis is marked with the radio-opaque marker, while the horizontal axis is provided by the CT laser marking (acknowledgment to our resident, Dr. Tomás Fernández, for volunteering for the figure). d CTF-guided percutaneous access to the lesion. Note that the access coincides with the point marked in (b) (triangle)