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Moreira P, Tuncali K, Tempany C, Tokuda J. AI-Based Isotherm Prediction for Focal Cryoablation of Prostate Cancer. Acad Radiol 2023; 30 Suppl 1:S14-S20. [PMID: 37236896 PMCID: PMC10524864 DOI: 10.1016/j.acra.2023.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/04/2023] [Accepted: 04/15/2023] [Indexed: 05/28/2023]
Abstract
RATIONALE AND OBJECTIVES Focal therapies have emerged as minimally invasive alternatives for patients with localized low-risk prostate cancer (PCa) and those with postradiation recurrence. Among the available focal treatment methods for PCa, cryoablation offers several technical advantages, including the visibility of the boundaries of frozen tissue on the intraprocedural images, access to anterior lesions, and the proven ability to treat postradiation recurrence. However, predicting the final volume of the frozen tissue is challenging as it depends on several patient-specific factors, such as proximity to heat sources and thermal properties of the prostatic tissue. MATERIALS AND METHODS This paper presents a convolutional neural network model based on 3D-Unet to predict the frozen isotherm boundaries (iceball) resultant from a given a cryo-needle placement. Intraprocedural magnetic resonance images acquired during 38 cases of focal cryoablation of PCa were retrospectively used to train and validate the model. The model accuracy was assessed and compared against a vendor-provided geometrical model, which is used as a guideline in routine procedures. RESULTS The mean Dice Similarity Coefficient using the proposed model was 0.79±0.08 (mean+SD) vs 0.72±0.06 using the geometrical model (P<.001). CONCLUSION The model provided an accurate iceball boundary prediction in less than 0.4second and has proven its feasibility to be implemented in an intraprocedural planning algorithm.
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Affiliation(s)
- Pedro Moreira
- Brigham and Women's Hospital, 75 Francis St, Boston, MA 22115 (P.M., K.T., C.T., J.T.); Harvard Medical School, 25 Shattuck St, Boston, MA 02115 (P.M., K.T., C.T., J.T.).
| | - Kemal Tuncali
- Brigham and Women's Hospital, 75 Francis St, Boston, MA 22115 (P.M., K.T., C.T., J.T.); Harvard Medical School, 25 Shattuck St, Boston, MA 02115 (P.M., K.T., C.T., J.T.)
| | - Clare Tempany
- Brigham and Women's Hospital, 75 Francis St, Boston, MA 22115 (P.M., K.T., C.T., J.T.); Harvard Medical School, 25 Shattuck St, Boston, MA 02115 (P.M., K.T., C.T., J.T.)
| | - Junichi Tokuda
- Brigham and Women's Hospital, 75 Francis St, Boston, MA 22115 (P.M., K.T., C.T., J.T.); Harvard Medical School, 25 Shattuck St, Boston, MA 02115 (P.M., K.T., C.T., J.T.)
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Campagnoli E, Ballatore A, Giaretto V, Anselmino M. Calorimetric analysis of ice onset temperature during cryoablation: a model approach to identify early predictors of effective applications. Sci Rep 2021; 11:15798. [PMID: 34349185 PMCID: PMC8339075 DOI: 10.1038/s41598-021-95204-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 07/22/2021] [Indexed: 12/01/2022] Open
Abstract
Aim of the present study is to analyze thermal events occurring during cryoablation. Different bovine liver samples underwent freezing cycles at different cooling rate (from 0.0075 to 25 K/min). Ice onset temperature and specific latent heat capacity of the ice formation process were measured according to differential scanning calorimetry signals. A computational model of the thermal events occurring during cryoablation was compiled using Neumann’s analytical solution. Latent heat (#1 = 139.8 ± 7.4 J/g, #2 = 147.8 ± 7.9 J/g, #3 = 159.0 ± 4.1 J/g) of all liver samples was independent of the ice onset temperature, but linearly dependent on the water content. Ice onset temperature was proportional to the logarithm of the cooling rate in the range 5 ÷ 25 K/min (#3a = − 12.2 °C, #3b = − 16.2 °C, #3c = − 6.6 °C at 5K/min; #3a = − 16.5 °C, #3b = − 19.3 °C, #3c = − 11.6 °C at 25 K/min). Ice onset temperature was associated with both the way in which the heat involved into the phase transition was delivered and with the thermal gradient inside the tissue. Ice onset temperature should be evaluated in the early phase of the ablation to tailor cryoenergy delivery. In order to obtain low ice trigger temperatures and consequent low ablation temperatures a high cooling rate is necessary.
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Affiliation(s)
| | - Andrea Ballatore
- Division of Cardiology, "Città della Salute e della Scienza di Torino" Hospital, Department of Medical Sciences, University of Turin, corso Dogliotti 14, 10126, Turin, Italy
| | | | - Matteo Anselmino
- Division of Cardiology, "Città della Salute e della Scienza di Torino" Hospital, Department of Medical Sciences, University of Turin, corso Dogliotti 14, 10126, Turin, Italy.
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Giaretto V, Ballatore A, Passerone C, Desalvo P, Matta M, Saglietto A, De Salve M, Gaita F, Panella B, Anselmino M. Thermodynamic properties of atrial fibrillation cryoablation: a model-based approach to improve knowledge on energy delivery. J R Soc Interface 2019; 16:20190318. [PMID: 31530136 DOI: 10.1098/rsif.2019.0318] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The objective of this study is to describe a suitable model of atrial fibrillation cryoablation thermodynamic properties. Three different thermal loads were applied to a cylindrical copper element simulating the cryoprobe, thermally coupled with a Peltier stack producing the freezing effect, and in contact with a bovine liver sample. Thermal events occurring inside the samples were measured using mirror image technique. Heat subtracted flux during ice formation and minimum temperature measured at probe-tissue interface were, respectively, 1.33 W cm-2 and -27.8°C for Sample#0, 1.88 W cm-2 and -35.6°C for Sample#1 and 1.82 W cm-2 and 1.44 W cm-2 before and after the ice trigger, respectively, and -29.3°C for Sample#2. Ice trigger temperature was around -8.5°C for Sample#0 and Sample#2, and -10.4°C for Sample#1. In all the investigated samples, ice front penetration was proportional to the square root of time and its velocity depended on the heat flux subtracted. The fraction of the useful energy spent for ice formation was less than 60% for Sample#0, and about 80% for Sample#1 and for Sample#2, before the reduction of the removed heat flux. Freezing time exceeding a cut-off, according to the heat subtracted flux, does not improve the procedure effectiveness and is detrimental to the surrounding tissues.
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Affiliation(s)
| | - Andrea Ballatore
- Division of Cardiology, 'Città della Salute e della Scienza di Torino' Hospital, Department of Medical Sciences, University of Turin, Turin, Italy
| | - Claudio Passerone
- Department of Electronics and Telecommunications, Politecnico di Torino, Italy
| | - Paolo Desalvo
- Division of Cardiology, 'Città della Salute e della Scienza di Torino' Hospital, Department of Medical Sciences, University of Turin, Turin, Italy
| | - Mario Matta
- Division of Cardiology, 'Città della Salute e della Scienza di Torino' Hospital, Department of Medical Sciences, University of Turin, Turin, Italy
| | - Andrea Saglietto
- Division of Cardiology, 'Città della Salute e della Scienza di Torino' Hospital, Department of Medical Sciences, University of Turin, Turin, Italy
| | | | - Fiorenzo Gaita
- Department of Cardiology, Clinica Pinna Pintor, Turin, Italy
| | | | - Matteo Anselmino
- Division of Cardiology, 'Città della Salute e della Scienza di Torino' Hospital, Department of Medical Sciences, University of Turin, Turin, Italy
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Computational study of the effects of arterial bifurcation on the temperature distribution during cryosurgery. Biomed Eng Online 2018; 17:4. [PMID: 29338729 PMCID: PMC5771102 DOI: 10.1186/s12938-018-0438-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 01/10/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Thermally significant blood flows into locally cooled diseased tissues and warm them during cryosurgery so that the iceball is often hard to cover the whole diseased volume. This paper is aimed at investigating the effects of large arterial bifurcation on the temperature distribution during cryosurgery through simulation method. METHODS A parametric geometry model is introduced to construct a close-to-real arterial bifurcation. The three-dimensional transient conjugate heat transfer between bifurcated artery and solid tissues with phase change during cryosurgery is performed by finite volume method. RESULTS The discussion was then made on the effects of the relative position between cryoprobe and artery bifurcation, the inlet velocity of root artery and the layout of multiple cryoprobes on the temperature distribution and iceball evolution. The results show that the thermal interaction between blood flow and iceball growth near bifurcation is considerable complex. The thermal effects of bifurcation could modulate the iceball morphology, severely weaken its freezing volume and prevent the blood vessel from being frozen. CONCLUSION The present work is expected to be valuable in optimizing cryosurgery scheme of the situation that the bifurcated artery is embedded into the disease tissue.
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Mirror image technique for the thermal analysis in cryoablation: Experimental setup and validation. Cryobiology 2017; 79:56-64. [PMID: 28939114 DOI: 10.1016/j.cryobiol.2017.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/05/2017] [Accepted: 09/10/2017] [Indexed: 11/20/2022]
Abstract
The paper presents a set of experiments that were performed to characterize the freezing front propagation in water first, and in an agar-gel solution afterwards. The experimental setup made of Peltier devices, to emulate the cryogenic effect, and a copper cold finger, to mimic the cold probe interface, are described. We claim that by monitoring some temperatures at the generating cryodevice, several pieces of information can be derived through the cold interface to assess the outside thermodynamic changes. The employed technique, known as mirror image, allows determining the occurrence of the initial ice formation outside the cryo-probe and in the surrounding material, also with different magnitudes of the thermal contact resistance at the cold interface. For both water and agar the ice penetration was found to be non linear versus time, and proportional to the square root of time in the performed experiments. The ice drift velocity decreases according to its penetration inside the tested materials. At the beginning of ice formation, the measured drift velocities are approximately 0.11 mm/s and 0.06 mm/s for water and agar, respectively, and after the ice penetrates 2 mm, they become approximately 0.03 mm/s for both materials.
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Ge MY, Shu C, Yang WM, Chua KJ. Incorporating an immersed boundary method to study thermal effects of vascular systems during tissue cryo-freezing. J Therm Biol 2017; 64:92-99. [PMID: 28166952 DOI: 10.1016/j.jtherbio.2017.01.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 01/19/2017] [Accepted: 01/19/2017] [Indexed: 11/19/2022]
Abstract
In this paper, the three-dimensional thermal effects of a clinically-extracted vascular tissue undergoing cryo-freezing are numerically investigated. Based on the measured experimental temperature field, the numerical results of the Pennes bioheat model combined with the boundary condition-enforced immersed boundary method (IBM) agreed well with experimental data with a maximum temperature discrepancy of 2.9°C. For simulating the temperature profile of a tumor sited in a dominantly vascularized tissue, our model is able to capture with ease the thermal effects at specified junctions of the blood vessels. The vascular complexity and the ice-ball shape irregularity which cannot be easily quantified via clinical experiments are also analyzed and compared for both two-dimensional and three-dimensional settings with different vessel configurations and developments. For the three-dimensional numerical simulations, a n-furcated liver vessels model from a three-dimensional segmented volume using hole-making and subdivision methods is applied. A specific study revealed that the structure and complexity of the vascular network can markedly affect the tissue's freezing configuration with increasing ice-ball irregularity for greater blood vessel complexity.
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Affiliation(s)
- M Y Ge
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore
| | - C Shu
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore
| | - W M Yang
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore
| | - K J Chua
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore.
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Kassab GS, An G, Sander EA, Miga MI, Guccione JM, Ji S, Vodovotz Y. Augmenting Surgery via Multi-scale Modeling and Translational Systems Biology in the Era of Precision Medicine: A Multidisciplinary Perspective. Ann Biomed Eng 2016; 44:2611-25. [PMID: 27015816 DOI: 10.1007/s10439-016-1596-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 03/18/2016] [Indexed: 12/18/2022]
Abstract
In this era of tremendous technological capabilities and increased focus on improving clinical outcomes, decreasing costs, and increasing precision, there is a need for a more quantitative approach to the field of surgery. Multiscale computational modeling has the potential to bridge the gap to the emerging paradigms of Precision Medicine and Translational Systems Biology, in which quantitative metrics and data guide patient care through improved stratification, diagnosis, and therapy. Achievements by multiple groups have demonstrated the potential for (1) multiscale computational modeling, at a biological level, of diseases treated with surgery and the surgical procedure process at the level of the individual and the population; along with (2) patient-specific, computationally-enabled surgical planning, delivery, and guidance and robotically-augmented manipulation. In this perspective article, we discuss these concepts, and cite emerging examples from the fields of trauma, wound healing, and cardiac surgery.
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Affiliation(s)
- Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, 92121, USA
| | - Gary An
- Department of Surgery, University of Chicago, Chicago, IL, 60637, USA
| | - Edward A Sander
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - Michael I Miga
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235, USA
| | - Julius M Guccione
- Department of Surgery, University of California, San Francisco, CA, 94143, USA
| | - Songbai Ji
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA.,Department of Surgery and of Orthopaedic Surgery, Geisel School of Medicine, Dartmouth College, Hanover, NH, 03755, USA
| | - Yoram Vodovotz
- Department of Surgery, University of Pittsburgh, W944 Starzl Biomedical Sciences Tower, 200 Lothrop St., Pittsburgh, PA, 15213, USA. .,Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15219, USA.
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Computational Modeling for Enhancing Soft Tissue Image Guided Surgery: An Application in Neurosurgery. Ann Biomed Eng 2015; 44:128-38. [PMID: 26354118 DOI: 10.1007/s10439-015-1433-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 08/18/2015] [Indexed: 01/14/2023]
Abstract
With the recent advances in computing, the opportunities to translate computational models to more integrated roles in patient treatment are expanding at an exciting rate. One area of considerable development has been directed towards correcting soft tissue deformation within image guided neurosurgery applications. This review captures the efforts that have been undertaken towards enhancing neuronavigation by the integration of soft tissue biomechanical models, imaging and sensing technologies, and algorithmic developments. In addition, the review speaks to the evolving role of modeling frameworks within surgery and concludes with some future directions beyond neurosurgical applications.
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He ZZ, Liu J. An efficient thermal evolution model for cryoablation with arbitrary multi-cryoprobe configuration. Cryobiology 2015; 71:318-28. [PMID: 26256654 DOI: 10.1016/j.cryobiol.2015.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/04/2015] [Accepted: 08/04/2015] [Indexed: 11/29/2022]
Abstract
Cryoablation has been demonstrated powerful in treating of a variety of diseases, especially for the tumor ablation, which destroys the target tissue through the controlled freezing of cryoprobe. The prediction of temperature evolution during cryoablation is of great importance for developing and improving clinical procedure. This paper presented an efficient thermal model to characterize the freezing effect of cryoprobe with arbitrary layout including its size, orientation and number. The key step of the presented model is to establish a boundary heat source method to implicitly characterize the heat transfer from cryoprobe with fixed temperature or convective heat transfer boundary condition, which is furthermore incorporated to a fast parallel alternating direction explicit (PADE) finite difference method for computation acceleration. A novel dynamical and conformal computational region is designed through the shortest distance definition to balance the thermal effect of tissue and computational efficiency. The detailed test cases including a real head tissue demonstrated that the current model can accurately predict the temperature field evolution induced by arbitrary multi-cryoprobe configuration, and achieve significant computational ability due to allowable large time step (100-fold compared with the explicit finite difference method), compact computational region (at least reducing 40% number of voxels) and high parallel efficiency (speedup ratio about 8 for 12 threads) for complex tissue structure.
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Affiliation(s)
- Zhi-Zhu He
- Key Laboratory of Cryogenics, and Beijing Key Laboratory of Cryo-Biomedical Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Jing Liu
- Key Laboratory of Cryogenics, and Beijing Key Laboratory of Cryo-Biomedical Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China; Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
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Ahmed M, Solbiati L, Brace CL, Breen DJ, Callstrom MR, Charboneau JW, Chen MH, Choi BI, de Baère T, Dodd GD, Dupuy DE, Gervais DA, Gianfelice D, Gillams AR, Lee FT, Leen E, Lencioni R, Littrup PJ, Livraghi T, Lu DS, McGahan JP, Meloni MF, Nikolic B, Pereira PL, Liang P, Rhim H, Rose SC, Salem R, Sofocleous CT, Solomon SB, Soulen MC, Tanaka M, Vogl TJ, Wood BJ, Goldberg SN. Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update. J Vasc Interv Radiol 2014; 25:1691-705.e4. [PMID: 25442132 PMCID: PMC7660986 DOI: 10.1016/j.jvir.2014.08.027] [Citation(s) in RCA: 332] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 02/11/2014] [Accepted: 03/26/2014] [Indexed: 12/12/2022] Open
Abstract
Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes.
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Affiliation(s)
- Muneeb Ahmed
- Department of Radiology, Beth Israel Deaconess Medical Center 1 Deaconess Rd, WCC-308B, Boston, MA 02215.
| | - Luigi Solbiati
- Department of Radiology, Ospedale Generale, Busto Arsizio, Italy
| | - Christopher L Brace
- Departments of Radiology, Biomedical Engineering, and Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - David J Breen
- Department of Radiology, Southampton University Hospitals, Southampton, England
| | | | | | - Min-Hua Chen
- Department of Ultrasound, School of Oncology, Peking University, Beijing, China
| | - Byung Ihn Choi
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Thierry de Baère
- Department of Imaging, Institut de Cancérologie Gustave Roussy, Villejuif, France
| | - Gerald D Dodd
- Department of Radiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Damian E Dupuy
- Department of Diagnostic Radiology, Rhode Island Hospital, Providence, Rhode Island
| | - Debra A Gervais
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - David Gianfelice
- Medical Imaging, University Health Network, Laval, Quebec, Canada
| | | | - Fred T Lee
- Department of Radiology, University of Wisconsin Hospital and Clinics, Madison, Wisconsin
| | - Edward Leen
- Department of Radiology, Royal Infirmary, Glasgow, Scotland
| | - Riccardo Lencioni
- Department of Diagnostic Imaging and Intervention, Cisanello Hospital, Pisa University Hospital and School of Medicine, University of Pisa, Pisa, Italy
| | - Peter J Littrup
- Department of Radiology, Karmonos Cancer Institute, Wayne State University, Detroit, Michigan
| | | | - David S Lu
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - John P McGahan
- Department of Radiology, Ambulatory Care Center, UC Davis Medical Center, Sacramento, California
| | | | - Boris Nikolic
- Department of Radiology, Albert Einstein Medical Center, Philadelphia, Pennsylvania
| | - Philippe L Pereira
- Clinic of Radiology, Minimally-Invasive Therapies and Nuclear Medicine, Academic Hospital Ruprecht-Karls-University Heidelberg, Heilbronn, Germany
| | - Ping Liang
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China
| | - Hyunchul Rhim
- Department of Diagnostic Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Steven C Rose
- Department of Radiology, University of California, San Diego, San Diego, California
| | - Riad Salem
- Department of Radiology, Northwestern University, Chicago, Illinois
| | | | - Stephen B Solomon
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Michael C Soulen
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Thomas J Vogl
- Institute for Diagnostic and Interventional Radiology, University Hospital Frankfurt, Johann Wolfgang Goethe-University, Frankfurt, Germany
| | - Bradford J Wood
- Radiology and Imaging Science, National Institutes of Health, Bethesda, Maryland
| | - S Nahum Goldberg
- Department of Radiology, Image-Guided Therapy and Interventional Oncology Unit, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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Jiang CP, Wu MC, Wu YS. Inducing occlusion effect in Y-shaped vessels using high-intensity focused ultrasound: finite element analysis and phantom validation. Comput Methods Biomech Biomed Engin 2012; 15:323-32. [DOI: 10.1080/10255842.2010.535521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Cho-Pei Jiang
- Department of Power Mechanical Engineering, National Formosa University, Yunlin County, Taiwan.
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Characterization of irreversible electroporation ablation in in vivo porcine liver. AJR Am J Roentgenol 2012; 198:W62-8. [PMID: 22194517 DOI: 10.2214/ajr.11.6940] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE The purpose of this study was to prospectively characterize and optimize irreversible electroporation ablation to determine the best parameters to achieve the largest target zones of coagulation for two electrodes. MATERIALS AND METHODS Ultrasound-guided irreversible electroporation ablation (n=110) was performed in vivo in 25 pig livers using two 18-gauge electroporation electrodes and an irreversible electroporation generator. Five variables for energy deposition and electrode configuration were sequentially studied: number of electrical pulses (n=20-90), length of pulses (20-100 microseconds), generator voltage (2250-3000 V), interelectrode spacing (1.5-2.5 cm), and length of active electrode exposure (1.0-3.0 cm). Zones of ablation were determined at gross pathology and histopathology 2-3 hours after irreversible electroporation. Dimensions were compared and subjected to statistical analysis. RESULTS For 1.5-cm spacing and 2-cm electrode exposure at 2250 V, there was no statistical difference in the size of coagulation when varying the number or length of pulses from 50 to 90 repetitions or 50-100 microseconds, respectively, with each parameter combination yielding 3.0±0.4×1.7±0.4×3.0±0.6 cm (width, depth, and height, respectively). Yet, increasing the pulse width or number over 70 caused increased hyperechogenic or gas and coagulation around the electrode. Increasing the voltage from 2250-3000 V for 70 pulses of 70 microseconds increased coagulation to 3.1±0.4×2.0±0.2 cm (p<0.01 for depth). Greater coagulation width of 3.9±0.5 cm (p<0.01) was achieved at 2-cm interelectrode spacing (with similar depth of 1.9±0.4 cm). However, consistent results required 90 repetitions and a 100-microsecond pulse width; 2.5-cm spacing resulted in two separate zones of ablation. Although electrode exposure did not influence width or depth, a linear correlation (r2=0.77) was noted for height, which ranged from 2.0±0.2-5.0±0.8 cm (for 1- and 3-cm exposures, respectively). CONCLUSION Predictable zones of tissue destruction can be achieved for irreversible electroporation. Ablation dimensions are sensitive to multiple parameters, suggesting that precise technique and attention to detail will be particularly important when using this modality.
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