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What guidance code is most appropriate to assign? Is code 76940 reported due to the documentation of US guidance used for probe placement and subsequent ultrasound monitoring of the ablation? Or is code 77013 reported, as CT was used to validate the trajectory of the probes and CT imaging was performed to complete the procedure? "PROCEDURE: Percutaneous microwave ablation of a right hepatic lobe lesion. The patient was prepped and draped in sterile fashion. Under real-time ultrasound guidance, microwave probes were inserted bracketing the lesion. Unenhanced CT confirmed parallel trajectory of the probes and approximate positioning by landmarks. Ablation was performed with real-time ultrasound monitoring. Then, the probes were retracted 2 cm each and additional ablation performed. Tract ablation was performed as the probes were removed. Finally, contrast enhanced CT of the abdomen targeted at the liver was performed in the arterial and portal venous phases. IMPRESSION: Successful CT and ultrasound-guided microwave ablation of the right hepatic lobe lesion."