HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Antoch, G. Articles by Kuehl, H. Search for Related Content PubMed PubMed Citation Articles by Antoch, G. Articles by Kuehl, H.

Assessment of Liver Tissue After Radiofrequency Ablation: Findings with Different Imaging Procedures

¹ Department of Diagnostic and Interventional Radiology, University Hospital Essen, Essen, Germany
² Department of Nuclear Medicine, University Hospital Essen, Essen, Germany
³ Department of Pathology, University Hospital Essen, Essen, Germany

Our goal was to assess the typical appearance of normal liver tissue immediately after radiofrequency ablation (RF-ablation) when imaged with contrast-enhanced ultrasound, CT, MRI, ¹⁸F-FDG PET, and PET/CT. Methods: Nineteen RF-ablation sessions were performed on nontumorous liver tissue of 10 Göttingen Mini Pigs. CT, ultrasound, MRI, ¹⁸F-FDG PET, and PET/CT were performed immediately after the intervention. All imaging procedures were evaluated qualitatively for areas of increased contrast enhancement (morphologic imaging) and regions of elevated tracer uptake (functional imaging). Images were assessed quantitatively by determination of ratios (r_p/p) comparing contrast enhancement/tracer uptake in the periphery of the necrosis with contrast enhancement/tracer uptake of normal liver parenchyma. Results: On morphologic imaging, an increase in contrast enhancement surrounding the ablative necrosis was detected in all lesions. Quantification of this area of increased contrast enhancement revealed ratios of r_p/p = 1.57 ± 0.2 for CT and r_p/p = 1.57 ± 0.19 for MRI. On PET and PET/CT, homogeneous tracer utilization was found surrounding all lesions. There were no areas of a focal or rim-like increase in glucose metabolism. The ratio r_p/p was found to be 1.05 ± 0.08 for functional data. Histologic examination revealed pooling of blood in the sinusoids of the lesion’s periphery that was caused by outflow obstruction due to the central necrosis. Conclusion: On morphologic imaging, a rim-like increase of contrast enhancement was found immediately after RF-ablation resembling peripheral hyperperfusion. This area of contrast enhancement may hamper detection of residual tumor. On the basis of homogeneous tracer distribution surrounding the area of necrosis, PET and PET/CT may serve for early assessment of patients after RF-ablation.

Key Words: radiofrequency ablation • liver • ¹⁸F-FDG PET • PET/CT

This article has been cited by other articles:

				L.-F. de Geus-Oei, D. Vriens, H. W.M. van Laarhoven, W. T.A. van der Graaf, and W. J.G. Oyen Monitoring and Predicting Response to Therapy with 18F-FDG PET in Colorectal Cancer: A Systematic Review J. Nucl. Med., May 1, 2009; 50(Suppl_1): 43S - 54S. [Abstract] [Full Text] [PDF]

				A. Bao, B. Goins, G. D. Dodd III, A. Soundararajan, C. Santoyo, R. A. Otto, M. D. Davis, and W. T. Phillips Real-Time Iterative Monitoring of Radiofrequency Ablation Tumor Therapy with 15O-Water PET Imaging J. Nucl. Med., October 1, 2008; 49(10): 1723 - 1729. [Abstract] [Full Text] [PDF]

				A. H. Khandani, B. F. Calvo, B. H. O'Neil, J. Jorgenson, and M. A. Mauro A Pilot Study of Early 18F-FDG PET to Evaluate the Effectiveness of Radiofrequency Ablation of Liver Metastases Am. J. Roentgenol., November 1, 2007; 189(5): 1199 - 1202. [Abstract] [Full Text] [PDF]

				F. M. Vogt, G. Antoch, P. Veit, L. S. Freudenberg, N. Blechschmid, O. Diersch, A. Bockisch, J. Barkhausen, and H. Kuehl Morphologic and Functional Changes in Nontumorous Liver Tissue After Radiofrequency Ablation in an In Vivo Model: Comparison of 18F-FDG PET/CT, MRI, Ultrasound, and CT J. Nucl. Med., November 1, 2007; 48(11): 1836 - 1844. [Abstract] [Full Text] [PDF]

				W. V. Vogel, J. A. van Dalen, B. Wiering, H. Huisman, F. H.M. Corstens, T. J.M. Ruers, and W. J.G. Oyen Evaluation of Image Registration in PET/CT of the Liver and Recommendations for Optimized Imaging J. Nucl. Med., June 1, 2007; 48(6): 910 - 919. [Abstract] [Full Text] [PDF]

				T. M. Blodgett, C. C. Meltzer, and D. W. Townsend PET/CT: Form and Function Radiology, February 1, 2007; 242(2): 360 - 385. [Abstract] [Full Text] [PDF]

				H. Kuehl, P. Veit, S. J. Rosenbaum, A. Bockisch, and G. Antoch Can PET/CT Replace Separate Diagnostic CT for Cancer Imaging? Optimizing CT Protocols for Imaging Cancers of the Chest and Abdomen J. Nucl. Med., January 1, 2007; 48(1_suppl): 45S - 57S. [Abstract] [Full Text] [PDF]