Fig. 9

Pulmonary metastases. A focal lung nodule is found in a 65-year-old female diagnosed with ovarian carcinoma. A biopsy reveals a non-small-cell carcinoma. A multidisciplinary team meeting leads to the choice for RF ablation treatment. Coronal reconstructions of the lesion in the right upper lobe before (first column), 24 h after the first RF ablation (second column), and 24 h after microwave ablation (third column) are demonstrated. a A focal nodule of 9 mm in the upper lobe is seen on the 70-keV lung window (black arrow) prior to the ablation. This nodule is “enhanced” on the synthesised monochromatic images compared to the water map image. This “increase in density” is better appreciated on the 40-keV rather than on the 70-keV images. Twenty-four hours after the first ablation, the spicular nodule appears enlarged on the lung windows. On the 40-keV image, a focal enhancement (arrow) is noted at the inferior border of the ablation zone, again more clearly visible compared to the 70-keV image. After re-ablation with microwave technique, we notice more important changes on the lung window than after the first ablation. b The iodine content of the hypermetabolic lesion before the RF ablation is most observable on the greyscale- and colour-coded iodine images (circles). The nodule is hypermetabolic on PET/CT. Twenty-four hours after the first ablation, the greyscale- and colour-coded iodine maps clearly show the focal area of iodine uptake (white arrows) on the inferior border. PET/CT confirms hypermetabolic remnants (yellow arrow). After re-ablation, the larger area of thermal damage has lost its internal focal iodine uptake, which is most appreciable on the iodine-coded images (arrowheads). Images after the re-ablation lack FDG uptake on PET/CT