Published in:
01-02-2012 | Interventional
MRI contrast enhancement of malignant liver tumours following successful cryoablation
Published in: European Radiology | Issue 2/2012
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Objectives
To assess the incidence and degree of MRI contrast enhancement in liver tumours following successful percutaneous cryoablation.
Methods
Thirty-eight patients with liver metastases (n = 29) or hepatocellular carcinoma (n = 9) underwent percutaneous cryoablation of 45 tumours between March 2004 and June 2009, with complete ablation zone coverage of the tumour and no local recurrence on follow-up imaging to date (range 3–60 months, mean 16). Contrast-enhanced MRI was used to assess 45 tumours at 24 h, 32 tumours at 2–4 months, and 21 tumours at 5–7 months. Percentage of tumours with contrast enhancement was assessed using dynamic spoiled gradient echo T1-weighted images.
Results
Twenty-four hours post-cryoablation, 23 out of 45 tumours (51%) enhanced compared with 42 out of 43 (98%) pre-ablation (p < 0.001). Mean percentage tumour enhancement decreased from 157% (range 26–745%) pre-ablation, to 107% (27–260%) at 24 h (p = 0.003), and 43% (24–103%) at 2–4 months (p < 0.001). The incidence and degree of tumour enhancement decreased through 5–7 months.
Conclusions
Unlike previously reported studies of radiofrequency ablation, successful cryoablation of liver tumours is often associated with persistent tumour contrast enhancement on MRI performed at 24 h and decreasing over 2–7 months.
Key Points
• Liver neoplasms often demonstrate MRI contrast enhancement following successful percutaneous cryoablation.
• This differs from radiofrequency ablation techniques where contrast enhancement suggests residual tumour
• This difference could potentially lead to important errors in follow up strategies.