PURPOSE: The aim of this study was to compare the size and shape of the indicated ablation zone using magnetic resonance (MR) imaging with different contrast weightings after MR-guided radiofrequency ablation (RFA) at 1.5 T. MATERIALS AND METHODS: Magnetic resonance images of 50 patients treated for hepatic malignancies using MR-guided RFA were retrospectively evaluated. Areas indicating ablation zones in contrast-enhanced images were compared with nonenhanced T1- and T2-weighted images acquired after the intervention and 1 and 7 months after therapy. Corresponding slices were selected and registered to each other. Regions indicating ablation zones were segmented and compared. Areas in cm, positive predictive value, and sensitivity of native T1- and T2-weighted images were calculated with regard to their accordance with the contrast-enhanced images. RESULTS: Directly after the intervention, the ratios between the areas of the ablation zone in the contrast-enhanced and the tested sequences were 1.02 ± 0.12 in the T1-weighted images and 2.03 ± 0.78 in the T2-weighted images. Sensitivity (portion of the coagulation zone that was correctly detected based on the tested sequences) was 0.88 ± 0.08 using the T1-weighted and 0.54 ± 0.20 using the T2-weighted images. The positive predictive values were 0.89 ± 0.06 (T1 weighted) and 0.93 ± 0.06 (T2 weighted). One month after therapy, the ratios between the areas in the contrast-enhanced and the tested sequences were 1.02 ± 0.12 in the T1-weighted images and 1.04 ± 0.25 in the T2-weighted images. Seven months after therapy, the ratios were 1.04 ± 0.16 in the T1-weighted and 1.18 ± 0.22 in the T2-weighted images. CONCLUSION: In examinations performed directly after the intervention, the T2-weighted images tend to underestimate the ablation zone, whereas T1-weighted images clearly better reflect the ablation zone. T1-weighted images therefore seem more adequate for repetitive monitoring of MR-guided RFA at 1.5 T.
PURPOSE: The aim of this study was to compare the size and shape of the indicated ablation zone using magnetic resonance (MR) imaging with different contrast weightings after MR-guided radiofrequency ablation (RFA) at 1.5 T. MATERIALS AND METHODS: Magnetic resonance images of 50 patients treated for hepatic malignancies using MR-guided RFA were retrospectively evaluated. Areas indicating ablation zones in contrast-enhanced images were compared with nonenhanced T1- and T2-weighted images acquired after the intervention and 1 and 7 months after therapy. Corresponding slices were selected and registered to each other. Regions indicating ablation zones were segmented and compared. Areas in cm, positive predictive value, and sensitivity of native T1- and T2-weighted images were calculated with regard to their accordance with the contrast-enhanced images. RESULTS: Directly after the intervention, the ratios between the areas of the ablation zone in the contrast-enhanced and the tested sequences were 1.02 ± 0.12 in the T1-weighted images and 2.03 ± 0.78 in the T2-weighted images. Sensitivity (portion of the coagulation zone that was correctly detected based on the tested sequences) was 0.88 ± 0.08 using the T1-weighted and 0.54 ± 0.20 using the T2-weighted images. The positive predictive values were 0.89 ± 0.06 (T1 weighted) and 0.93 ± 0.06 (T2 weighted). One month after therapy, the ratios between the areas in the contrast-enhanced and the tested sequences were 1.02 ± 0.12 in the T1-weighted images and 1.04 ± 0.25 in the T2-weighted images. Seven months after therapy, the ratios were 1.04 ± 0.16 in the T1-weighted and 1.18 ± 0.22 in the T2-weighted images. CONCLUSION: In examinations performed directly after the intervention, the T2-weighted images tend to underestimate the ablation zone, whereas T1-weighted images clearly better reflect the ablation zone. T1-weighted images therefore seem more adequate for repetitive monitoring of MR-guided RFA at 1.5 T.
Authors: Muneeb Ahmed; Luigi Solbiati; Christopher L Brace; David J Breen; Matthew R Callstrom; J William Charboneau; Min-Hua Chen; Byung Ihn Choi; Thierry de Baère; Gerald D Dodd; Damian E Dupuy; Debra A Gervais; David Gianfelice; Alice R Gillams; Fred T Lee; Edward Leen; Riccardo Lencioni; Peter J Littrup; Tito Livraghi; David S Lu; John P McGahan; Maria Franca Meloni; Boris Nikolic; Philippe L Pereira; Ping Liang; Hyunchul Rhim; Steven C Rose; Riad Salem; Constantinos T Sofocleous; Stephen B Solomon; Michael C Soulen; Masatoshi Tanaka; Thomas J Vogl; Bradford J Wood; S Nahum Goldberg Journal: J Vasc Interv Radiol Date: 2014-10-23 Impact factor: 3.464
Authors: Susann-Cathrin Olthof; Daniel Wessling; Moritz T Winkelmann; Hansjörg Rempp; Konstantin Nikolaou; Rüdiger Hoffmann; Stephan Clasen Journal: Insights Imaging Date: 2022-03-21
Authors: Moritz T Winkelmann; Rami Archid; Georg Gohla; Gerald Hefferman; Jens Kübler; Jakob Weiss; Stephan Clasen; Konstantin Nikolaou; Silvio Nadalin; Rüdiger Hoffmann Journal: Cancer Imaging Date: 2020-05-27 Impact factor: 3.909