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Olthof SC, Wessling D, Winkelmann MT, Rempp H, Nikolaou K, Hoffmann R, Clasen S. Single-centre survival analysis over 10 years after MR-guided radiofrequency ablation of liver metastases from different tumour entities. Insights Imaging 2022; 13:48. [PMID: 35312842 PMCID: PMC8938560 DOI: 10.1186/s13244-022-01178-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/09/2022] [Indexed: 11/10/2022] Open
Abstract
Background Radiofrequency ablation (RFA) is a minimal-invasive, local therapy in patients with circumscribed metastatic disease. Although widely used, long time survival analysis of treated liver metastases is still pending while also analysing the patients’ experience of MR-based radiofrequency. Methods Monocentric, retrospective analysis of long-time overall and progression free survival (OS; PFS) of 109 patients, treated with MRI-guided hepatic RFA between 1997 and 2010, focusing on colorectal cancer patients (CRC). Complimentary therapies were evaluated and Kaplan Meier-curves were calculated. Patients’ experience of RFA was retrospectively assessed in 28 patients. Results 1-, 3-, 5-, 10-year OS rates of 109 patients with different tumour entities were 83.4%, 53.4%, 31.0% and 22.9%, median 39.2 months, with decreasing survival rates for larger metastases size. For 72 CRC patients 1-, 3-, 5-, 10-year OS rates of 90.2%, 57.1%, 36.1% and 26.5% were documented (median 39.5 months). Thereof, beneficial outcome was detected for patients with prior surgery of the CRC including chemotherapy (median 53.0 months), and for liver metastases up to 19 mm (28.5% after 145 months). Hepatic PFS was significantly higher in patients with liver lesions up to 29 mm compared to larger ones (p = 0.035). 15/28 patients remembered RFA less incriminatory than other applied therapies. Conclusions This is the first single-centre, long-time OS and PFS analysis of MRI-guided hepatic RFA of liver metastases from different tumour entities, serving as basis for further comparison studies. Patients’ experience of MR based RFA should be analysed simultaneously to the performed RFA in the future.
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Affiliation(s)
- Susann-Cathrin Olthof
- Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany.
| | - Daniel Wessling
- Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Moritz T Winkelmann
- Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Hansjörg Rempp
- Radiologie Waiblingen, Alter Postplatz 2, 71332, Waiblingen, Germany
| | - Konstantin Nikolaou
- Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Stephan Clasen
- Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany.,Department of Radiology, Kreiskliniken Reutlingen, Steinenbergstraße 31, 72764, Reutlingen, Germany
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Kessler DE, Weiss J, Rempp H, Pereira PL, Nikolaou K, Clasen S, Hoffmann R. In vitro artifact assessment of an MR-compatible, microwave antenna device for percutaneous tumor ablation with fluoroscopic MRI-sequences. MINIM INVASIV THER 2017; 27:60-68. [PMID: 29231067 DOI: 10.1080/13645706.2017.1414062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To evaluate artifact configuration and diameters of a magnetic resonance (MR) compatible microwave (MW) applicator using near-realtime MR-fluoroscopic sequences for percutaneous tumor ablation procedures. MATERIAL AND METHODS Two MW applicators (14 G and 16 G) were tested in an ex-vivo phantom at 1.5 T with two 3 D fluoroscopic sequences: T1-weighted spoiled Gradient Echo (GRE) and T1/T2-weighted Steady State Free Precession (SSFP) sequence. Applicator orientation to main magnetic field (B0), slice orientation and phase encoding direction (PED) were systematically varied. The influence of these variables was assessed with ANOVA and post-hoc testing. RESULTS The artifact was homogenous along the whole length of both antennas with all tested parameters. The tip artifact diameter of the 16 G antenna measured 6.9 ± 1.0 mm, the shaft artifact diameter 8.6 ± 1.2 mm and the Tip Location Error (TLE) was 1.5 ± 1.2 mm.The tip artifact diameter of the 14 G antenna measured 7.7 ± 1.2 mm, the shaft artifact diameter 9.6 ± 1.5 mm and TLE was 1.6 ± 1.2 mm. Orientation to B0 had no statistically significant influence on tip artifact diameters (16 G: p = .55; 14 G: p = .07) or TLE (16 G: p = .93; 14 G: p = .26). GRE sequences slightly overestimated the antenna length with TLE(16 G) = 2.6 ± 0.5 mm and TLE(14 G) = 2.7 ± 0.7 mm. CONCLUSIONS The MR-compatible MW applicator's artifact seems adequate with an acceptable TLE for safe applicator positioning during near-realtime fluoroscopic MR-guidance.
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Affiliation(s)
- David-Emanuel Kessler
- a Department of Diagnostic and Interventional Radiology , Eberhard Karls University , Tuebingen , Germany
| | - Jakob Weiss
- a Department of Diagnostic and Interventional Radiology , Eberhard Karls University , Tuebingen , Germany
| | - Hansjörg Rempp
- a Department of Diagnostic and Interventional Radiology , Eberhard Karls University , Tuebingen , Germany
| | - Philippe L Pereira
- b Department of Radiology, Minimally Invasive Therapies and Nuclear Medicine , SLK-Kliniken Heilbronn , Heilbronn , Germany
| | - Konstantin Nikolaou
- a Department of Diagnostic and Interventional Radiology , Eberhard Karls University , Tuebingen , Germany
| | - Stephan Clasen
- a Department of Diagnostic and Interventional Radiology , Eberhard Karls University , Tuebingen , Germany
| | - Rüdiger Hoffmann
- a Department of Diagnostic and Interventional Radiology , Eberhard Karls University , Tuebingen , Germany
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Hoffmann R, Kessler DE, Weiss J, Clasen S, Pereira PL, Nikolaou K, Rempp H. Preclinical evaluation of an MR-compatible microwave ablation system and comparison with a standard microwave ablation system in an ex vivo bovine liver model. Int J Hyperthermia 2017; 33:617-623. [DOI: 10.1080/02656736.2017.1284349] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - David-Emanuel Kessler
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Jakob Weiss
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Stephan Clasen
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Philippe L. Pereira
- Department of Radiology, Minimally Invasive Therapies and Nuclear Medicine, SLK-Kliniken Heilbronn GmbH, Heilbronn, Germany
| | - Konstantin Nikolaou
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Hansjörg Rempp
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Tuebingen, Germany
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Hoffmann R, Rempp H, Keßler DE, Weiß J, Pereira PL, Nikolaou K, Clasen S. MR-guided microwave ablation in hepatic tumours: initial results in clinical routine. Eur Radiol 2016; 27:1467-1476. [PMID: 27553935 DOI: 10.1007/s00330-016-4517-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/11/2016] [Accepted: 07/19/2016] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Evaluation of the technical success, patient safety and technical effectiveness of magnetic resonance (MR)-guided microwave ablation of hepatic malignancies. METHODS Institutional review board approval and informed patient consent were obtained. Fifteen patients (59.8 years ± 9.5) with 18 hepatic malignancies (7 hepatocellular carcinomas, 11 metastases) underwent MR-guided microwave ablation using a 1.5-T MR system. Mean tumour size was 15.4 mm ± 7.7 (7-37 mm). Technical success and ablation zone diameters were assessed by post-ablative MR imaging. Technique effectiveness was assessed after 1 month. Complications were classified according to the Common Terminology Criteria for Adverse Events (CTCAE). Mean follow-up was 5.8 months ± 2.6 (1-10 months). RESULTS Technical success and technique effectiveness were achieved in all lesions. Lesions were treated using 2.5 ± 1.2 applicator positions. Mean energy and ablation duration per tumour were 37.6 kJ ± 21.7 (9-87 kJ) and 24.7 min ± 11.1 (7-49 min), respectively. Coagulation zone short- and long-axis diameters were 31.5 mm ± 10.5 (16-65 mm) and 52.7 mm ± 15.4 (27-94 mm), respectively. Two CTCAE-2-complications occurred (pneumothorax, pleural effusion). Seven patients developed new tumour manifestations in the untreated liver. Local tumour progression was not observed. CONCLUSIONS Microwave ablation is feasible under near real-time MR guidance and provides effective treatment of hepatic malignancies in one session. KEY POINTS • Planning, applicator placement and therapy monitoring are possible without using contrast enhancement • Energy transmission from the generator to the scanner room is safely possible • MR-guided microwave ablation provides effective treatment of hepatic malignancies in one session • Therapy monitoring is possible without applicator retraction from the ablation site.
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Affiliation(s)
- Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany.
| | - Hansjörg Rempp
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany
| | - David-Emanuel Keßler
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany
| | - Jakob Weiß
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany
| | - Philippe L Pereira
- Department of Radiology, Minimally Invasive Therapies and Nuclear Medicine, SLK-Kliniken Heilbronn GmbH, Am Gesundbrunnen 20-26, 74078, Heilbronn, Germany
| | - Konstantin Nikolaou
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany
| | - Stephan Clasen
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany
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Hoffmann R, Rempp H, Schraml C, Schwenzer N, Grözinger G, Blumenstock G, Rothgang E, Pereira PL, Claussen CD, Clasen S. Diffusion-weighted imaging during MR-guided radiofrequency ablation of hepatic malignancies: analysis of immediate pre- and post-ablative diffusion characteristics. Acta Radiol 2015; 56:908-16. [PMID: 25182804 DOI: 10.1177/0284185114545148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 06/28/2014] [Indexed: 01/26/2023]
Abstract
BACKGROUND Previous studies have shown a benefit of magnetic resonance (MR)-diffusion-weighted imaging (DWI) for follow-up after liver radiofrequency (RF) ablation. However, no data are available concerning acute changes of DWI characteristics immediately after RF ablation. PURPOSE To analyze and compare the MR-diffusion characteristics of pre-interventional hepatic malignancies and the ablation zone during successful MR-guided RF ablation. MATERIAL AND METHODS This retrospective study was conducted in accordance with the guidelines of the local institutional review board. Forty-seven patients with 29 HCC (24 patients) and 30 hepatic metastases (23 patients) underwent MR-guided radiofrequency ablation including DWI before and immediately after ablation (b = 0, 400, 800 s/mm(2)). Two reviewers (A and B) analyzed DWI with focus on detectability of the tumor before ablation and characteristics of the coagulative area after treatment. Mean apparent diffusion coefficient (ADC) was compared between liver, untreated tumor, and hyperintense areas in post-ablative DWI (b = 800 s/mm(2)) with the paired Student's t-test. RESULTS Pre-ablative: the reviewers classified 19/29 (A) and 23/29 (B) HCC and 25/30 (A and B) metastases as detectable in DWI. Post-ablative: a hyperintense rim surrounding the ablation zone was observed in 28/29 treated HCC and 30/30 treated metastases (A and B). A homogenous hypointense central ablation zone was found in 18/29 (A) and 20/29 (B) treated HCC and 17/30 (A & B) treated metastases in DWI. ADC of the rim was significantly lower than ADC of the liver (P < 0.001). CONCLUSION DWI enables visualization of the target tumor in MR-guided liver radiofrequency ablation in most cases. A common post-ablative DWI finding is a hyperintense rim with decreased ADC surrounding the ablation zone.
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Affiliation(s)
- Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University, Tübingen, Germany
| | - Hansjörg Rempp
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University, Tübingen, Germany
| | - Christina Schraml
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University, Tübingen, Germany
| | - Nina Schwenzer
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University, Tübingen, Germany
| | - Gerd Grözinger
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University, Tübingen, Germany
| | - Gunnar Blumenstock
- Department of Clinical Epidemiology and Applied Biometry, Eberhard Karls University, Tübingen, Germany
| | - Eva Rothgang
- Center for Applied Medical Imaging, Siemens Corporate Research, Germany and Baltimore, MD, USA
| | - Philippe L Pereira
- Department of Radiology, Minimally Invasive Therapies and Nuclear Medicine, SLK-Kliniken Heilbronn GmbH, Heilbronn, Germany
| | - Claus D Claussen
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University, Tübingen, Germany
| | - Stephan Clasen
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University, Tübingen, Germany
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Brendle C, Schwenzer NF, Rempp H, Schmidt H, Pfannenberg C, la Fougère C, Nikolaou K, Schraml C. Assessment of metastatic colorectal cancer with hybrid imaging: comparison of reading performance using different combinations of anatomical and functional imaging techniques in PET/MRI and PET/CT in a short case series. Eur J Nucl Med Mol Imaging 2015. [DOI: 10.1007/s00259-015-3137-z] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Hoffmann R, Rempp H, Eibofner F, Keßler DE, Blumenstock G, Weiß J, Pereira PL, Nikolaou K, Clasen S. In vitro artefact assessment of a new MR-compatible microwave antenna and a standard MR-compatible radiofrequency ablation electrode for tumour ablation. Eur Radiol 2015; 26:771-9. [DOI: 10.1007/s00330-015-3891-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 06/02/2015] [Accepted: 06/10/2015] [Indexed: 12/13/2022]
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Panahova S, Rempp H, Sipos B, Malek NP, Boozari B. [Primary perivascular epitheloid cell tumour (PEComa) of the liver - is a new entity of the liver tumors?]. Z Gastroenterol 2015; 53:399-408. [PMID: 25965987 DOI: 10.1055/s-0034-1399391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Perivascular epitheloid cell tumor (PEComa) is a rare tumor, characterized by dual Expression of smooth muscle and melanocytic markers. Due to the development of diagnostic procedures, we now diagnose PEComa more often. We report about a case of PEComa of the liver as an accidental finding. We analyze the clinical and morphological characteristics of this tumor and compare it with the data of the literature. Management of patients with PEComa is not yet standardized; therefore biopsy with immunhistochemical staining is necessary for the diagnosis. In case of liver tumors which cannot be classified by their morphology on imaging modalities, it is important to think about this rare entity.
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Affiliation(s)
- S Panahova
- Medizinische Klinik I, Universitätsklinikum Tübingen, Tübingen, Germany
| | - H Rempp
- Abteilung für diagnostische und interventionelle Radiologie, Radiologische Klinik, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - B Sipos
- Institut für Pathologie und Neuropathologie, Universitätsklinikum Tübingen, Germany
| | - N P Malek
- Medizinische Klinik I, Universitätsklinikum Tübingen, Tübingen, Germany
| | - B Boozari
- Medizinische Klinik I, Universitätsklinikum Tübingen, Tübingen, Germany
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Rempp H, Schwenk J, Reischl G, Nikolaou K, La Fougère C, Pfannenberg C. Vergleich von 68Ga-PSMA und 11C-Cholin-PET/CT in der Diagnostik des Prostatakarzinoms. ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1551228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hoffmann R, Rempp H, Syha R, Ketelsen D, Pereira PL, Claussen CD, Clasen S. Transarterial chemoembolization using drug eluting beads and subsequent percutaneous MR-guided radiofrequency ablation in the therapy of intermediate sized hepatocellular carcinoma. Eur J Radiol 2014; 83:1793-8. [PMID: 25052871 DOI: 10.1016/j.ejrad.2014.06.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 06/10/2014] [Accepted: 06/26/2014] [Indexed: 12/27/2022]
Abstract
OBJECTIVE To evaluate safety, efficacy, survival and recurrence-free survival of transarterial chemoembolization (TACE) with drug eluting (DC) beads combined with MR-guided radiofrequency (RF) ablation for the treatment of hepatocellular carcinomas (HCC) larger than 3 cm. MATERIALS AND METHODS This retrospective study was approved by the institutional review board. 20 patients (69.6 years ± SD 8.8) with HCC underwent DC Bead TACE and subsequent MR-guided RF ablation. Treatment interval varied between 5 and 15 days. Mean HCC diameter was 39 mm ± SD 7 mm (range 31-50mm). Rates of recurrence-free survival and overall survival were estimated using the Kaplan-Meier method. RESULTS Technical success rate, primary and secondary technical effectiveness rate were 100%, 90% and 95%, respectively. Local tumour progression developed in one patient. Cumulative survival rates at 1, 3 and 5 years were 90% (Confidence Interval [CI]: 67%-97%), 50% (CI: 29%-70%), 27% (CI: 11%-51%) respectively. Median survival time was 37.4 months. During follow up (mean: 39.1 months ± SD 22.4; range 5-84 months), tumour progression in untreated liver developed in 14 cases. Cumulative recurrence-free survival rates at 1, 3 and 5 years were 48% (CI: 27-69%), 16% (5-39%), 16% (5-39%) respectively. Median recurrence-free survival time was 10.7 months. One major complication occurred due to misdiagnosed local recurrence. CONCLUSION In conclusion, we demonstrated that MR-guided RF ablation with subsequent DC Bead TACE is safe and effective in local tumour control in patients with intermediate sized HCC.
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Affiliation(s)
- Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
| | - Hansjörg Rempp
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
| | - Roland Syha
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
| | - Dominik Ketelsen
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
| | - Philippe L Pereira
- Department of Radiology, Minimally Invasive Therapies and Nuclearmedicine, SLK-Kliniken Heilbronn GmbH, Am Gesundbrunnen 20-26, 74078 Heilbronn, Germany.
| | - Claus D Claussen
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
| | - Stephan Clasen
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
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Hoffmann R, Rempp H, Schraml C, Schwenzer N, Grözinger G, Blumenstock G, Rothgang E, Pereira PL, Claussen CD, Clasen S. Diffusionsbildgebung während MR-gesteuerter Radiofrequenzablation primärer und sekundärer Lebertumoren. ROFO-FORTSCHR RONTG 2014. [DOI: 10.1055/s-0034-1373070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Rempp H, Hoffmann R, Loh H, Rothgang E, Pan L, Claussen CD, Clasen S. Visualisierung primärer und sekundärer Leberläsionen in fluoroskopischen MRT-Sequenzen. ROFO-FORTSCHR RONTG 2014. [DOI: 10.1055/s-0034-1373069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Hoffmann R, Bustamante J, Pitsaer C, Voigtländer M, Enderle MD, Claussen CD, Clasen S, Rempp H. Forms of energy delivery during cryo-cooled radiofrequency ablation for optimization of the ablation result. ROFO-FORTSCHR RONTG 2014; 186:945-50. [PMID: 24691837 DOI: 10.1055/s-0034-1366232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE Energy transfer from radiofrequency (RF) applicator to tissue is both precondition and limiting factor. The purpose of this ex vivo study was to examine the influence of form of energy delivery on ablation result during RF ablation with cryo-cooled applicators. MATERIALS AND METHODS One hundred eight ablations were performed in ex vivo bovine liver under continuous energy delivery (A), pulsed energy delivery with reduced current during ablation pause (B) and impedance-dependent energy delivery. Maximum ablation time was 20 min. Early termination of ablation in case of loss of conductivity. Optimal ablation parameters were assessed. Short axis diameter of the ablation zone and ablation duration were determined. Ablation results under mode A, B and C were compared with analysis of variance and Tukey-Kramer HSD test. Influence of ablation duration on short axis diameter was evaluated with regression analysis. RESULTS Significantly largest short axis diameter (51.1 mm ± SD 2.3; p = 0.01) was reached with impedance-dependent energy delivery (pulsed: 46.1 mm ± SD 5.6; continuous: 44.4 mm ± SD 4.1). Significantly longest ablation duration (1061.6 s ± SD 42.4; p = 0.01) was reached with impedance-dependent energy delivery (pulsed: 815.7 s ± 41.3; continuous: 715.3 s ± SD 82.2). Linear correlation between ablation duration and short axis diameter was calculated (R = 0.7). CONCLUSION Modification of energy delivery during RF ablation with cryo-cooled applicators improves energy transfer to tissue and enables larger ablation zones. KEY POINTS • Impedance-dependent energy delivery prevents early termination in kryo-based RF-ablation,• Impedance-dependent energy delivery enables larger ablation zones than continuous energy delivery,• Reduced current during ablation pause does not improve ablation results.
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Affiliation(s)
- R Hoffmann
- Diagnostic and Interventional Radiology, University Hospital Tübingen
| | - J Bustamante
- Diagnostic and Interventional Radiology, University Hospital Tübingen
| | - C Pitsaer
- ERBE Elektromedizin GmbH, ERBE, Derendingen
| | | | | | - C D Claussen
- Diagnostic and Interventional Radiology, University Hospital Tübingen
| | - S Clasen
- Diagnostic and Interventional Radiology, University Hospital Tübingen
| | - H Rempp
- Diagnostic and Interventional Radiology, University Hospital Tübingen
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Clasen S, Rempp H, Hoffmann R, Graf H, Pereira PL, Claussen CD. Image-guided radiofrequency ablation of hepatocellular carcinoma (HCC): Is MR guidance more effective than CT guidance? Eur J Radiol 2014; 83:111-6. [DOI: 10.1016/j.ejrad.2013.09.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 08/14/2013] [Accepted: 09/30/2013] [Indexed: 12/20/2022]
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Engeholm M, Leo-Kottler B, Rempp H, Lindig T, Lerche H, Kleffner I, Henes M, Dihné M. Encephalopathic Susac's Syndrome associated with livedo racemosa in a young woman before the completion of family planning. BMC Neurol 2013; 13:185. [PMID: 24274741 PMCID: PMC4222806 DOI: 10.1186/1471-2377-13-185] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 11/20/2013] [Indexed: 01/11/2023] Open
Abstract
Background Susac’s Syndrome (SS) consists of the triad of encephalopathy, branch retinal artery occlusions (BRAO) and hearing loss (HL). Histopathologically, SS is characterised by a microangiopathy, and some observations suggest that an immune-mediated damage of endothelial cells might play a role. These findings also implicate a similarity between SS and other autoimmune diseases, most notably juvenile dermatomyositis (JDM). However, SS and JDM are commonly thought to affect distinct and non-overlapping sets of organs, and it is currently not clear how these specificities arise. Moreover, in the absence of clinical trials, some authors suggest that therapeutic approaches in SS should rely on the model of other autoimmune diseases such as JDM. Case presentation Here, we report a case of SS in a 32-year-old pregnant woman. She initially was admitted to the hospital with subacute severe encephalopathy and multifocal neurologic signs. As cranial magnetic resonance imaging (MRI) revealed multifocal white matter lesions including the corpus callosum, erroneously a diagnosis of multiple sclerosis (MS) was made, and intravenous methylprednisolone (IVMP) therapy was initiated. A few days later, an exanthema appeared on the trunk and extremities, which was diagnosed as livedo racemosa (LR). Several weeks later, the patient was readmitted to the clinic with an obscuration of her left visual hemifield and a bilateral HL. Ophthalmologic examination revealed extensive ischemic damage to both retinae. Now the correct diagnosis of SS was established, based on the above triad of clinical symptoms in conjunction with typical MRI and fundoscopic findings. When SS was diagnosed, the standard therapy with intravenous cyclophosphamide (IVCTX) was not instituted because of a significant risk of permanent infertility. Instead, sustained control of disease activity could be achieved with a therapeutic regime combining prednisolone, intravenous immunoglobulins (IVIG), mycophenylate mofetil (MM), and methotrexate (MTX). Conclusions An association with LR has only been described in very few cases of SS before and further underlines the pathogenetic relationship between SS and other autoimmune diseases such as JDM. In young women with SS and the desire for a child the combination of MM and MTX may represent a reasonable alternative to IVCTX.
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Affiliation(s)
- Maik Engeholm
- Department of Neurology and Hertie Institute for Clinical Brain Research, Hoppe-Seyler-Str, 3, 72076 Tübingen, Germany.
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Hoffmann R, Rempp H, Pereira PL, Clasen S. [Image-guided therapy with closed MRI: an update]. Radiologe 2013; 53:986-92. [PMID: 24170285 DOI: 10.1007/s00117-012-2461-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
STANDARD RADIOLOGICAL METHODS Standard imaging modalities for percutaneous minimally invasive therapy are ultrasound, fluoroscopy and computed tomography. METHODICAL INNOVATIONS Magnetic resonance imaging is becoming increasingly more popular for minimally invasive procedures. The advantages are high soft-tissue contrast, the possibility of free selection of multiple imaging slices, multiple tools for intrainterventional monitoring and the absence of ionizing radiation for the patient and the interventional radiologist. ACHIEVEMENTS Magnetic resonance imaging is a promising imaging modality for minimally invasive procedures. The most common clinical applications are thermoablative procedures for treatment of hepatic, renal and prostatic malignancies.
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Affiliation(s)
- R Hoffmann
- Abteilung für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Deutschland,
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Rempp H, Loh H, Hoffmann R, Rothgang E, Pan L, Claussen CD, Clasen S. Liver lesion conspicuity during real-time MR-guided radiofrequency applicator placement using spoiled gradient echo and balanced steady-state free precession imaging. J Magn Reson Imaging 2013; 40:432-9. [PMID: 24677447 DOI: 10.1002/jmri.24371] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 07/26/2013] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To retrospectively evaluate the conspicuity of liver lesions in a fluoroscopic spoiled gradient echo (GRE) and a balanced steady-state free precession (SSFP) magnetic resonance imaging (MRI) sequence. MATERIALS AND METHODS In all, 103 patients with hepatocellular carcinomas (HCC) (41) or liver metastases (67) were treated using MR-guided radiofrequency ablation in a wide-bore 1.5 T scanner. A multislice real-time spoiled GRE sequence allowing for a T1 weighting (T1W) and a balanced SSFP sequence allowing for a T2/T1W contrast were used for MR guidance. The contrast-to-noise-ratio (CNR) of the lesions was calculated and lesion conspicuity was assessed retrospectively (easily detectable / difficult to detect / not detectable). RESULTS HCC was easily detectable in 33/52% (GRE/SSFP), difficult to detect in 30/18%, and not detectable in 37/30% of the cases. Mean CNR varied widely (9.1 for GRE vs. 16.4 for SSFP). Liver metastases were easily detectable in 58/41% (GRE/SSFP), difficult to detect in 14/21%, and not detectable in 28/38% of the cases. Mean CNR for liver metastases was 11.5 (GRE) vs. 12.7 (SSFP). Twenty percent of all lesions could not be detected with either of the MR fluoroscopy sequences. CONCLUSION MR fluoroscopy using GRE and SSFP contrast enabled real-time detectability of 80% of the liver lesions.
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Affiliation(s)
- Hansjörg Rempp
- Eberhard Karls University of Tübingen, Department of Diagnostic and Interventional Radiology, Tübingen, Germany
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Hoffmann R, Rempp H, Erhard L, Blumenstock G, Pereira PL, Claussen CD, Clasen S. Comparison of four microwave ablation devices: an experimental study in ex vivo bovine liver. Radiology 2013; 268:89-97. [PMID: 23440327 DOI: 10.1148/radiol.13121127] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE To compare volume, sphericity, and short-axis diameter of the coagulation zone of four commercially available microwave ablation systems with three technical concepts in an ex vivo setting and to formulate mathematical models to predict these quantities. MATERIALS AND METHODS Two high-power systems (systems A and B), a system that enables simultaneous use of three antennas (system C), and a non-perfusion-cooled system that automatically adapts power and frequency (system D) were tested in ex vivo bovine livers (108 ablations). Coagulation volume, sphericity, and mean short-axis diameter were assessed, and mathematical functions were fitted for each system and assessed with the coefficient of determination (R(2)). Analysis of variance and Tukey post hoc tests were used for interdevice comparison after 5 and 10 minutes and after maximum recommended ablation time. RESULTS Volume and short-axis diameter were determined by using a mathematical model for every system, with coefficients of determination of 0.75-0.98 and 0.70-0.97, respectively. Correlation for determination of sphericity was lower (R(2) = 0.01-0.68). Mean results with ablation performed according to manufacturer recommendations were as follows: Volume, sphericity, and short-axis diameter were 57.5 cm(3), 0.75, and 43.4 mm, respectively, for system A; 72.3 cm(3), 0.68, and 45.5 mm, respectively, for system B; 17.1 cm(3), 0.58, and 26.8 mm, respectively, for system C (one antenna); 76.5 cm(3), 0.89, and 50.6 mm, respectively, for system C (three antennas); and 56.0 cm(3), 0.64, and 40.9 mm, respectively, for system D. Systems A (mean volume, 52.4 cm(3) ± 4.5 [standard deviation]) and B (39.4 cm(3) ± 1.7) reach large ablation zones with 5-minute ablation. CONCLUSION The largest ablation zone is obtained with systems B and C (three antennas) under maximum recommended ablation duration and with system A under short ablation time. The most spherical zone is obtained with system C (three antennas).
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Affiliation(s)
- Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology and Department of Medical Biometry, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
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Rempp H, Voigtländer M, Schenk M, Enderle D, Greiner TO, Scharpf M, Neugebauer A, Hoffmann R, Claussen CD, Clasen S. Gas-gekühlte Radiofrequenzablation als Alternative zur herkömmlichen Radiofrequenzablation und zur Mikrowellenablation: eine In-vivo-Vergleichsstudie. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0032-1329762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
CLINICAL ISSUE The majority of patients with hepatic malignancies are not amenable to surgical resection. In some of these cases minimally invasive ablative therapies are a treatment option. STANDARD TREATMENT Besides radiofrequency ablation, the most common ablative therapies are cryoablation, laser ablation and microwave ablation. TREATMENT INNOVATIONS The classic fields of application of microwave ablation are the treatment of malignancies of the liver, kidneys and lungs. Furthermore, cases of treatment of bone tumors and tumors of the adrenal gland have been reported as well as treatment of secondary hypersplenism. PERFORMANCE The manufacturers of microwave systems pursue different strategies to reach an optimal ablation zone, such as water or gas cooling of the antenna, the simultaneous use of different antennas or an automatic modulation of the microwave energy and frequency. ACHIEVEMENTS In contrast to other tumor ablation methods microwave ablation causes a direct heating of a tissue volume, thus this method is less vulnerable to the cooling effect of vessels in the ablation zone. Moreover the electric conductivity of the treated tissue does not influence microwave radiation so that microwave ablation has advantages for the treatment of high-resistance organs, such as the lungs or bone. Some publications have shown that microwave ablation causes larger ablation zones in less time in comparison to radiofrequency ablation. PRACTICAL RECOMMENDATIONS Classic indications for microwave ablation are the treatment of malignancies of the liver, lungs and kidneys. Initial technical problems have been solved, so that an increasing significance of the microwave ablation among the ablative therapies is to be expected.
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Affiliation(s)
- R Hoffmann
- Abteilung für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Deutschland.
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Rempp H, Hoffmann R, Roland J, Pereira PL, Schick F, Claussen CD, Clasen S. MRT-Temperaturmessung bei Radiofrequenzablation von Lebertumoren: Korrelation der Temperaturdaten mit der Ablationszone. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0032-1311448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Rempp H, Boss A, Helmberger T, Pereira P. The current role of minimally invasive therapies in the management of liver tumors. ACTA ACUST UNITED AC 2012; 36:635-47. [PMID: 21562884 DOI: 10.1007/s00261-011-9749-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This is a review of minimally invasive therapy options for liver tumors, such as highly focused ultrasound, microwave ablation, and irreversible electroporation, as well as new aspects of radiofrequency ablation. Radiofrequency ablation is recommended for patients with early-stage HCC with up to 3 lesions with a tumor diameter within 3 cm and for patients with non-resectable liver metastasis. Indications and contraindications to treatment are designated, and different modalities for image-based therapy guidance are compared. Options for therapy monitoring and controlling are reviewed, namely intraprocedural tools, imaging and functional parameters and their evolution during therapy. Prevention and control of local recurrences is discussed. We also present a short review of current clinical results in treating liver metastasis and primary liver tumors.
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Affiliation(s)
- Hansjörg Rempp
- Department on Diagnostic and Interventional Radiology, Eberhard Karls University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany.
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Hoffmann R, Rempp H, Schmidt D, Pereira PL, Claussen CD, Clasen S. Prolonged antibiotic prophylaxis in patients with bilioenteric anastomosis undergoing percutaneous radiofrequency ablation. J Vasc Interv Radiol 2012; 23:545-51. [PMID: 22365593 DOI: 10.1016/j.jvir.2011.12.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 12/20/2011] [Accepted: 12/24/2011] [Indexed: 01/02/2023] Open
Abstract
PURPOSE To reduce risk of development of a hepatic abscess in patients with preexisting bilioenteric anastomosis (BEA) undergoing radiofrequency (RF) ablation of hepatic tumors by use of prolonged antibiotic prophylaxis over at least 10 days. MATERIALS AND METHODS Between April 2003 and June 2011, 184 patients underwent 206 percutaneous RF ablation procedures for hepatic malignancies. Eight patients presented with BEA and were treated in 10 sessions at 14 tumor locations. These 8 patients were male and ranged in age from 55-73 years. Median follow-up was 34 months. Antibiotic prophylaxis was given before the intervention (n = 9, piperacillin/tazobactam; n = 1, ciprofloxacin). Oral antibiotic prophylaxis after the intervention was continued with ciprofloxacin for at least 10 days. In four cases, prophylaxis after the intervention was extended with additional antibiotics. RESULTS A liver abscess occurred 22 days after 1 of 10 RF ablation sessions in patients with preexisting BEA. The patient who developed an abscess presented with a large hepatocellular carcinoma (59 mm × 54 mm) and underwent transarterial chemoembolization 8 days before RF ablation. No hepatic abscess occurred after 196 RF ablation sessions in 176 patients without BEA. CONCLUSIONS Preexisting BEA is a risk factor for formation of hepatic abscesses after RF ablation. An antibiotic prophylaxis regimen before the intervention and for a prolonged period after the intervention that covers anaerobic bacteria for at least 10 days is presented. Combined therapy of transarterial chemoembolization and RF ablation increases the risk for complications in patients with known BEA.
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Affiliation(s)
- Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology, University of Tübingen, Hoppe-Seyler-Strasse 3, 72076 Tübingen.
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Rempp H, Hoffmann R, Roland J, Buck A, Kickhefel A, Claussen CD, Pereira PL, Schick F, Clasen S. Threshold-based prediction of the coagulation zone in sequential temperature mapping in MR-guided radiofrequency ablation of liver tumours. Eur Radiol 2011; 22:1091-100. [PMID: 22105843 DOI: 10.1007/s00330-011-2335-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/15/2011] [Accepted: 09/27/2011] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To evaluate different cut-off temperature levels for a threshold-based prediction of the coagulation zone in magnetic resonance (MR)-guided radiofrequency (RF) ablation of liver tumours. METHODS Temperature-sensitive measurements were acquired during RF ablation of 24 patients with primary (6) and secondary liver lesions (18) using a wide-bore 1.5 T MR sytem and compared with the post-interventional coagulation zone. Temperature measurements using the proton resonance frequency shift method were performed directly subsequent to energy application. The temperature maps were registered on the contrast-enhanced follow-up MR images acquired 4 weeks after treatment. Areas with temperatures above 50°, 55° and 60°C were segmented and compared with the coagulation zones. Sensitivity and positive predictive value were calculated. RESULTS No major complications occurred and all tumours were completely treated. No tumour recurrence was observed at the follow-up examination after 4 weeks. Two patients with secondary liver lesions showed local tumour recurrence after 4 and 7 months. The 60°C threshold level achieved the highest positive predictive value (87.7 ± 9.9) and the best prediction of the coagulation zone. CONCLUSIONS For a threshold-based prediction of the coagulation zone, the 60°C cut-off level achieved the best prediction of the coagulation zone among the tested levels. KEY POINTS • Temperature monitoring can be used to survey MR-guided radiofrequency ablation • The developing ablation zone can be estimated based on post-interventional temperature measurements • A 60°C threshold level can be used to predict the ablation zone • The 50°C and 55°C temperature zones tend to overestimate the ablation zone.
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Affiliation(s)
- Hansjörg Rempp
- Department on Diagnostic and Interventional Radiology, Eberhard Karls University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany.
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Hoffmann R, Thomas C, Rempp H, Schmidt D, Pereira PL, Claussen CD, Clasen S. Performing MR-guided biopsies in clinical routine: factors that influence accuracy and procedure time. Eur Radiol 2011; 22:663-71. [PMID: 21960160 DOI: 10.1007/s00330-011-2297-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 09/10/2011] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To assess the accuracy, the duration and factors that influence the duration of MRI-guided liver or soft-tissue biopsies. METHODS Nineteen liver biopsies and 19 soft-tissue biopsies performed using 1.5T-MRI guidance were retrospectively analysed. Diagnostic performance and complications were assessed. Intervention time was subdivided into preparation period, puncture period and control period. Correlation between procedure time and target size, skin-to-target-distance, used sequences and interventionalists' experience were analysed. RESULTS Overall sensitivity, specificity and accuracy were 0.86, 1.0 and 0.92, respectively. Two minor complications occurred. Overall median procedure time was 103.5 min. Liver biopsies lasted longer than soft-tissue biopsies (mean([soft-tissue]): 73.0 min, mean([liver]): 134.1 min, P < 0.001). The most time consuming part was the preparation period in both, soft-tissue and liver biopsies corresponding to 59.6% and 47.4% of the total intervention time, respectively. Total procedure time in liver biopsies (P = 0.027) and puncture period in liver and soft-tissue biopsies (P ([liver]) = 0.048, P ([soft-tissue]) = 0.005) was significantly prolonged for longer skin-to-target-distances. Lower numbers of image acquisitions (P ([liver]) = 0.0007, P ([soft-tissue]) = 0.0012) and interventionalists' experience reduces the procedure duration significantly (P < 0.05), besides all false-negative results appeared during the first five biopsies of each individual radiologist. CONCLUSION The interventionalists' experience, skin-to-target-distances and number of image acquisition influence the procedure time significantly. KEY POINTS •Appropriate training and supervision is essential for inexperienced interventionalists. •Two perpendicular image orientations should confirm the correct biopsy needle position. •Communication between interventionalist and technician is essential for a fluent biopsy procedure. •To shorten intervention time appropriate previous imaging is essential.
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Affiliation(s)
- Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology, University of Tübingen, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany
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Thomas C, Wojtczyk H, Rempp H, Clasen S, Horger M, von Lassberg C, Fritz J, Claussen CD, Pereira PL. Carbon fibre and nitinol needles for MRI-guided interventions: First in vitro and in vivo application. Eur J Radiol 2011; 79:353-8. [DOI: 10.1016/j.ejrad.2010.07.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 07/02/2010] [Accepted: 07/07/2010] [Indexed: 10/19/2022]
Affiliation(s)
- Christoph Thomas
- Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany.
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Kickhefel A, Rosenberg C, Weiss CR, Rempp H, Roland J, Schick F, Hosten N. Clinical evaluation of MR temperature monitoring of laser-induced thermotherapy in human liver using the proton-resonance-frequency method and predictive models of cell death. J Magn Reson Imaging 2011; 33:704-12. [PMID: 21563256 DOI: 10.1002/jmri.22499] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To assess the feasibility, precision, and accuracy of real-time temperature mapping (TMap) during laser-induced thermotherapy (LITT) for clinical practice in patients liver with a gradient echo (GRE) sequence using the proton resonance frequency (PRF) method. MATERIALS AND METHODS LITT was performed on 34 lesions in 18 patients with simultaneous real-time visualization of relative temperature changes. Correlative contrast-enhanced T1-weighted magnetic resonance (MR) images of the liver were acquired after treatment using the same slice positions and angulations as TMap images acquired during LITT. For each slice, TMap and follow-up images were registered for comparison. Afterwards, segmentation based on temperature (T) >52°C on TMap and based on necrosis seen on follow-up images was performed. These segmented structures were overlaid and divided into zones where the TMap was found to either over- or underestimate necrosis on the postcontrast images. Regions with T>52°C after 20 minutes were defined as necrotic tissue based on data received from two different thermal dose models. RESULTS The average intersecting region of TMap and necrotic zone was 87% ± 5%, the overestimated 13% ± 4%, and the underestimated 13% ± 5%. CONCLUSION This study demonstrates that MR temperature mapping appears reasonably capable of predicting tissue necrosis on the basis of indicating regions having greater temperatures than 52°C and could be used to monitor and adjust the thermal therapy appropriately during treatment.
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Rempp H, Clasen S, Pereira PL. Image-based monitoring of magnetic resonance-guided thermoablative therapies for liver tumors. Cardiovasc Intervent Radiol 2011; 35:1281-94. [PMID: 21785888 DOI: 10.1007/s00270-011-0227-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 06/23/2011] [Indexed: 12/27/2022]
Abstract
Minimally invasive treatment options for liver tumor therapy have been increasingly used during the last decade because their benefit has been proven for primary and inoperable secondary liver tumors. Among these, radiofrequency ablation has gained widespread consideration. Optimal image-guidance offers precise anatomical information, helps to position interventional devices, and allows for differentiation between already-treated and remaining tumor tissue. Patient safety and complete ablation of the entire tumor are the overriding objectives of tumor ablation. These may be achieved most elegantly with magnetic resonance (MR)-guided therapy, where monitoring can be performed based on precise soft-tissue imaging and additional components, such as diffusion-weighted imaging and temperature mapping. New MR scanner types and newly developed sequence techniques have enabled MR-guided intervention to move beyond the experimental phase. This article reviews the current role of MR imaging in guiding radiofrequency ablation. Signal characteristics of primary and secondary liver tumors are identified, and signal alteration during therapy is described. Diffusion-weighted imaging (DWI) and temperature mapping as special components of MR therapy monitoring are introduced. Practical information concerning coils, sequence selection, and parameters, as well as sequence gating, is given. In addition, sources of artifacts are identified and techniques to decrease them are introduced, and the characteristic signs of residual tumor in T1-, T2-, and DWI are described. We hope to enable the reader to choose MR sequences that allow optimal therapy monitoring depending on the initial signal characteristics of the tumor as well as its size and location in the liver.
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Affiliation(s)
- Hansjörg Rempp
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University of Tübingen, 72076, Tübingen, Germany.
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Clasen S, Rempp H, Boss A, Schmidt D, Fritz J, Schraml C, Schick F, Claussen CD, Pereira PL. MR-guided radiofrequency ablation of hepatocellular carcinoma: long-term effectiveness. J Vasc Interv Radiol 2011; 22:762-70. [PMID: 21530311 DOI: 10.1016/j.jvir.2011.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 03/01/2011] [Accepted: 03/04/2011] [Indexed: 01/20/2023] Open
Abstract
PURPOSE To evaluate long-term effectiveness of magnetic resonance (MR)-guided radiofrequency (RF) ablation of hepatocellular carcinoma (HCC). MATERIALS AND METHODS This prospective study was approved by the institutional review board. In 20 patients, 28 HCCs (mean diameter, 28.0 mm; range, 6-58 mm) were treated with 25 sessions of MR-guided RF ablation. Previous chemoembolization had been performed in nine HCCs with diameters greater than 3 cm. The entire RF ablation procedures were carried out on a 0.2-T open MR system. Placement of MR-compatible internally cooled electrodes was performed under MR fluoroscopic imaging with fast gradient-echo sequences. Therapeutic assessment was based on dynamic MR-imaging (1.5 T) at a mean follow-up of 24.2 months (range, 6-52 mo). RESULTS MR-guided RF ablation was technically successful in all 25 sessions (100%), as assessed at the end of each session. T2-weighted sequences were accurate to monitor the ablation zone and supported guidance of overlapping ablations if necessary. Technique effectiveness, defined as complete ablation confirmed at MR imaging 4 months after RF ablation, was achieved in 27 of 28 HCCs (96.4%). To achieve complete ablation, 25 of 27 tumors (92.6%) were treated in a single session and two tumors were treated twice. In one tumor initially defined as having been treated with technically effective RF ablation, local tumor progression was detected more than 4 months after ablation. Consequently, the available follow-up indicated complete ablation in 26 of 28 HCCs (92.9%). There was one major complication (4.0%) and one minor complication (4.0%). CONCLUSIONS On a long-term basis, MR-guided RF ablation is an effective therapy option in the treatment of HCC.
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Affiliation(s)
- Stephan Clasen
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Hoppe-Seyler Str. 3, 72076 Tübingen, Germany.
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Rempp H, Mezger D, Voigtländer M, Enderle M, Hoffmann R, Pereira PL, Claussen CD, Clasen S. Ex-vivo Vergleichsstudie von mono- und bipolaren intern gas- und wassergekühlten Radiofrequenzapplikatoren. ROFO-FORTSCHR RONTG 2011. [DOI: 10.1055/s-0031-1279419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Rempp H, Waibel L, Hoffmann R, Pereira PL, Claussen CD, Clasen S. MR-gesteuerte Radiofrequenzablation in einem weitgebohrten 1,5 T-System: Klinische Ergebnisse von 202 behandelten Lebertumoren. ROFO-FORTSCHR RONTG 2011. [DOI: 10.1055/s-0031-1279578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Clasen S, Rempp H, Hoffmann R, Waibel L, Schmidt D, Schick F, Claussen CD, Pereira PL. MRT-gesteuerte Radiofrequenz-Ablation: Effektivitäts-Beurteilung in der Behandlung von 50 Patienten mit Hepatozellulärem Karzinom (HCC). ROFO-FORTSCHR RONTG 2011. [DOI: 10.1055/s-0031-1279418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Schmidt D, Clasen S, Schäfer J, Rempp H, Erdtmann B, König CW, Duda S, Trübenbach J, Kluba T, Claussen CD, Pereira PL. Manuelle versus maschinelle Bohrung in der CT gesteuerten RFA von Osteoid-osteomen - 11-jährige klinische Erfahrung. ROFO-FORTSCHR RONTG 2011. [DOI: 10.1055/s-0031-1279420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Hoffmann R, Rempp H, Schmidt D, Claussen CD, Pereira PL, Clasen S. Antibiotikaprophylaxe zur Prävention chologener Abszesse nach Radiofrequenz-Ablation bei Risikopatienten mit biliodigestiver Anastomose. ROFO-FORTSCHR RONTG 2011. [DOI: 10.1055/s-0031-1279090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Schmidt D, Clasen S, Schaefer J, Rempp H, Duda S, Trübenbach J, König C, Erdtmann B, Claussen C, Pereira P. CT-gesteuerte Radiofrequenz(RF)-Ablation von Osteoidosteomen: klinische Langzeitergebnisse. ROFO-FORTSCHR RONTG 2011; 183:381-7. [DOI: 10.1055/s-0029-1245998] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Clasen S, Rempp H, Schmidt D, Schraml C, Hoffmann R, Claussen CD, Pereira PL. Multipolar radiofrequency ablation using internally cooled electrodes in ex vivo bovine liver: correlation between volume of coagulation and amount of applied energy. Eur J Radiol 2010; 81:111-3. [PMID: 21112714 DOI: 10.1016/j.ejrad.2010.10.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 10/20/2010] [Accepted: 10/20/2010] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the relationship between applied energy and volume of coagulation induced by multipolar radiofrequency (RF) ablation. METHODS AND MATERIALS Multipolar RF ablations (n=80) were performed in ex vivo bovine liver. Three bipolar applicators with two electrodes located on each applicator shaft were placed in a triangular array. The power-output (75-225 W) and the distance between the different applicators (2, 3, 4, 5 cm) were systematically varied. The volume of confluent white coagulation and the amount of applied energy were assessed. Based on our experimental data the relationship between the volume of coagulation and applied energy was assessed by nonlinear regression analysis. The variability explained by the model was determined by the parameter r(2). RESULTS The volume of coagulation increases with higher amounts of applied energy. The maximum amount of energy was applied at a power-output of 75 W and an applicator distance of 5 cm. The corresponding maximum volume of coagulation was 324 cm(3) and required an application of 453 kJ. The relationship between amount of applied energy (E) and volume (V) of coagulation can be described by the function, V=4.39E(0.7) (r(2)=0.88). By approximation the volume of coagulation can be calculated by the linear function V=0.61E+40.7 (r(2)=0.87). CONCLUSION Ex vivo the relationship between volume of coagulation and amount of applied energy can be described by mathematical modeling. The amount of applied energy correlates to the volume of coagulation and may be a useful parameter to monitor multipolar RF ablation.
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Affiliation(s)
- Stephan Clasen
- University Hospital, Department of Diagnostic and Interventional Radiology, Hoppe-Seyler Str. 3, 72076 Tübingen, Germany.
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Thomas C, Müller-Bierl BM, Rempp H, Siegmann K, Martirosian P, Claussen CD, Pereira PL. In vitro Assessment of Artifacts from Commercially Available Markers for Image-guided Preoperative Marking of Bone and Soft Tissue Lesions. J Vasc Interv Radiol 2010; 21:1100-4. [DOI: 10.1016/j.jvir.2010.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 02/28/2010] [Accepted: 04/03/2010] [Indexed: 10/19/2022] Open
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Würslin C, Machann J, Rempp H, Claussen C, Yang B, Schick F. Topography mapping of whole body adipose tissue using A fully automated and standardized procedure. J Magn Reson Imaging 2010; 31:430-9. [PMID: 20099357 DOI: 10.1002/jmri.22036] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
PURPOSE To obtain quantitative measures of human body fat compartments from whole body MR datasets for the risk estimation in subjects prone to metabolic diseases without the need of any user interaction or expert knowledge. MATERIALS AND METHODS Sets of axial T1-weighted spin-echo images of the whole body were acquired. The images were segmented using a modified fuzzy c-means algorithm. A separation of the body into anatomic regions along the body axis was performed to define regions with visceral adipose tissue present, and to standardize the results. In abdominal image slices, the adipose tissue compartments were divided into subcutaneous and visceral compartments using an extended snake algorithm. The slice-wise areas of different tissues were plotted along the slice position to obtain topographic fat tissue distributions. RESULTS Results from automatic segmentation were compared with manual segmentation. Relatively low mean deviations were obtained for the class of total tissue (4.48%) and visceral adipose tissue (3.26%). The deviation of total adipose tissue was slightly higher (8.71%). CONCLUSION The proposed algorithm enables the reliable and completely automatic creation of adipose tissue distribution profiles of the whole body from multislice MR datasets, reducing whole examination and analysis time to less than half an hour.
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Affiliation(s)
- Christian Würslin
- Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany.
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Schmidt D, Clasen S, Schäfer J, Rempp H, König CW, Duda S, Erdtmann B, Claussen C, Pereira PL. 10-jährige klinische Erfahrung der CT gesteuerten Radiofrequenzablation von Osteoid-Osteomen. ROFO-FORTSCHR RONTG 2010. [DOI: 10.1055/s-0030-1252786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Schmidt D, Clasen S, Weihusen A, Rempp H, Schraml C, Boss A, Schick F, Claussen C, Pereira PL. Computerunterstützte Bildgebung zur Optimierung des Therapieerfolges der MR-gesteuerten Radiofrequenzablation von malignen Leberneoplasien. ROFO-FORTSCHR RONTG 2010. [DOI: 10.1055/s-0030-1252885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Clasen S, Rempp H, Dorn J, Schmidt D, Claussen C, Pereira PL. Experimentelle ex-vivo Evaluation der hepatischen Mikrowellen-Ablation. ROFO-FORTSCHR RONTG 2010. [DOI: 10.1055/s-0030-1252796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Schmidt D, Clasen S, Rempp H, Weihusen A, Kern B, Claussen C, Pereira PL. Bestimmung der Wertigkeit der computerunterstützten präinterventionellen Planung und Ergebniskontrolle für die MR gesteuerte RFA von malignen Lebertumoren. ROFO-FORTSCHR RONTG 2010. [DOI: 10.1055/s-0030-1252768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Thomas C, Springer F, Röthke M, Rempp H, Clasen S, Fritz J, Claussen CD, Pereira PL. In Vitro Assessment of Needle Artifacts with an Interactive Three-dimensional MR Fluoroscopy System. J Vasc Interv Radiol 2010; 21:375-80. [DOI: 10.1016/j.jvir.2009.11.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2009] [Revised: 11/08/2009] [Accepted: 11/11/2009] [Indexed: 01/20/2023] Open
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Rempp H, Clasen S, Schraml C, Schmidt D, Boss A, Roland J, Kickhefel A, Miller S, Schick F, Claussen C, Pereira PL. MR-Temperaturmapping bei der Radiofrequenzablation von hepatischen Tumoren: Wie genau kann das Koagulationsareal vorhergesagt werden? ROFO-FORTSCHR RONTG 2010. [DOI: 10.1055/s-0030-1253030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bartsch I, Bläser S, Röseler S, Sandrock K, Busse A, Huber M, Rempp H, Lieber M, Horn J, Brendle C, Zieger B. Human endothelial and platelet septin SEPT11: Cloning of novel variants and characterisation of interaction partners. Thromb Haemost 2010; 104:1201-10. [DOI: 10.1160/th10-07-0472] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 08/15/2010] [Indexed: 11/05/2022]
Abstract
SummarySeptins are cytoskeletal GTPases forming heteropolymeric complexes involved in processes characterised by active membrane movement such as cytokinesis, vesicle trafficking, and exocytosis. Septins are expressed in non-mitotic cells such as neurons and platelets. SEPT11 belongs to the SEPT6 group and was identified as interaction partner of SEPT5. We cloned and characterised novel SEPT11 variants and investigated interaction partners of SEPT11 in platelets and human umbilical vein endothelial cells. An endothelial cell library was used for cloning novel SEPT11 variants. Using Northern analysis the different SEPT11 transcripts were illustrated. Interaction studies were performed using yeast two-hybrid system, precipitation, FRET, and immunofluorescence microscopy. We demonstrate that SEPT11 partners with SEPT2, SEPT4 and SEPT7 using yeast two-hybrid system and precipitation. The interaction of SEPT11 with SEPT7 is also demonstrated by FRET. In addition to the known SEPT11 transcript (SEPT11_v1) we identified a novel SEPT11 variant (SEPT11_v2) as interaction partner of SEPT4 and SEPT7. Library screening of an endothelial cell library also revealed the presence of this novel SEPT11_v2 transcript. In addition, a third SEPT11 variant (SEPT11_v3) was identified. Expression of SEPT11_v1 and of SEPT11_v2 and SEPT11_v3 in human brain regions was investigated by Northern analysis. Further interaction partners of SEPT11 are characterised using immunofluorescence. Co-localisation of SEPT2, SEPT4, SEPT7 and SEPT11 with tubulin and transferrin receptor (endocytotic marker) is demonstrated. In addition, co-localisation of SEPT4 and SEPT11 with the vesicle-associated protein synaptobrevin 1 (VAMP1), but not clearly with actin, was shown. Only SEPT2 and SEPT7 definitely co-localised with actin, but not clearly with VAMP1.
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Rempp H, Clasen S, Boss A, Roland J, Kickhefel A, Schraml C, Claussen CD, Schick F, Pereira PL. Prediction of cell necrosis with sequential temperature mapping after radiofrequency ablation. J Magn Reson Imaging 2009; 30:631-9. [DOI: 10.1002/jmri.21863] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Rempp H, Martirosian P, Boss A, Clasen S, Kickhefel A, Kraiger M, Schraml C, Claussen C, Pereira P, Schick F. MR temperature monitoring applying the proton resonance frequency method in liver and kidney at 0.2 and 1.5 T: segment-specific attainable precision and breathing influence. Magn Reson Mater Phy 2008; 21:333-43. [DOI: 10.1007/s10334-008-0139-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 07/18/2008] [Accepted: 08/07/2008] [Indexed: 12/13/2022]
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Boss A, Rempp H, Martirosian P, Clasen S, Schraml C, Stenzl A, Claussen CD, Schick F, Pereira PL. Wide-bore 1.5 Tesla MR imagers for guidance and monitoring of radiofrequency ablation of renal cell carcinoma: initial experience on feasibility. Eur Radiol 2008; 18:1449-55. [PMID: 18351355 DOI: 10.1007/s00330-008-0894-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 01/29/2008] [Accepted: 02/04/2008] [Indexed: 01/18/2023]
Abstract
This study was conducted to test and demonstrate the feasibility of magnetic resonance (MR)-guided radiofrequency (RF) ablation of renal cell carcinoma (RCC) using a 1.5 T whole-body scanner equipped with a wide-bore superconductive magnet. Two patients with contrast-enhancing renal masses were treated with multipolar RF ablation (Celon ProSurge). Applicator navigation and near real-time ablation monitoring were performed in a wide-bore 1.5 T scanner using adapted fluoroscopic and diagnostic sequences. In addition to T2-weighted imaging for ablation monitoring, perfusion-weighted images acquired with an arterial spin-labeling technique (FAIR-TrueFISP) were applied. Results were compared to a previous study on 12 patients performed at 0.2 T. Navigation and monitoring of RF ablation using the wide-bore system operating at 1.5 T were clearly improved compared to former experiences on a 0.2 T MR unit. Fluoroscopic and diagnostic images for MR guidance could be acquired with distinctly higher image quality and shorter acquisition time resulting in higher accuracy of applicator placement and shorter treatment time. Spin-labeling perfusion imaging exhibited good image quality, potentially providing additional clinically important information. MR-guided RF ablation of RCC can safely be performed in a 1.5 T wide-bore scanner offering higher image quality, shorter acquisition time, and new monitoring modalities not feasible at 0.2 T.
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Affiliation(s)
- Andreas Boss
- Section of Experimental Radiology, Eberhard Karls University of Tübingen, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
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Rempp H, Boss A, Martirosian P, Claussen CD, Schick F. Ganzkörper-Magnetisierungstransfer-MR-Bildgebung. ROFO-FORTSCHR RONTG 2007. [DOI: 10.1055/s-2006-956197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Rempp H, Boss A, Kraiger M, Pereira P, Claussen CD, Schick F. MR-Thermographie an Leber und Nieren mittels Phasenkontrast-Methode – Einflüsse von Atmung und Bewegung auf die Messgenauigkeit. ROFO-FORTSCHR RONTG 2007. [DOI: 10.1055/s-2006-956196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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