Lack of Anatomical Concordance between Preablation and Postablation CT Images: A Risk Factor Related to Ablation Site Recurrence

Figure 4

Definition of ablation site recurrence. Examples of ablation site recurrences (ASRs). The largest diameter of both lesions on the right is in direct contact with the ablation zone. The lesion on the left is not an ASR, because the center of the line representing the largest diameter is not in direct contact with the ablation zone. It is more probably a satellite metastasis which was already present at the time of the ablation. Outgrowth of this lesion took place after the RFA procedure. This prerequisite is necessary to prevent erroneously identified outgrowing satellite lesions in the close vicinity of the ablated tumour as ASR.