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Wegierak D, Cooley MB, Perera R, Wulftange WJ, Gurkan UA, Kolios MC, Exner AA. Decorrelation Time Mapping as an Analysis Tool for Nanobubble-Based Contrast Enhanced Ultrasound Imaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2024; 43:2370-2380. [PMID: 38329864 PMCID: PMC11234354 DOI: 10.1109/tmi.2024.3364076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Nanobubbles (NBs; ~100-500 nm diameter) are preclinical ultrasound (US) contrast agents that expand applications of contrast enhanced US (CEUS). Due to their sub-micron size, high particle density, and deformable shell, NBs in pathological states of heightened vascular permeability (e.g. in tumors) extravasate, enabling applications not possible with microbubbles (~1000-10,000 nm diameter). A method that can separate intravascular versus extravascular NB signal is needed as an imaging biomarker for improved tumor detection. We present a demonstration of decorrelation time (DT) mapping for enhanced tumor NB-CEUS imaging. In vitro models validated the sensitivity of DT to agent motion. Prostate cancer mouse models validated in vivo imaging potential and sensitivity to cancerous tissue. Our findings show that DT is inversely related to NB motion, offering enhanced detail of NB dynamics in tumors, and highlighting the heterogeneity of the tumor environment. Average DT was high in tumor regions (~9 s) compared to surrounding normal tissue (~1 s) with higher sensitivity to tumor tissue compared to other mapping techniques. Molecular NB targeting to tumors further extended DT (11 s) over non-targeted NBs (6 s), demonstrating sensitivity to NB adherence. From DT mapping of in vivo NB dynamics we demonstrate the heterogeneity of tumor tissue while quantifying extravascular NB kinetics and delineating intra-tumoral vasculature. This new NB-CEUS-based biomarker can be powerful in molecular US imaging, with improved sensitivity and specificity to diseased tissue and potential for use as an estimator of vascular permeability and the enhanced permeability and retention (EPR) effect in tumors.
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Li S, Zhou Z, Wu S, Wu W. Ultrasound Homodyned-K Contrast-Weighted Summation Parametric Imaging Based on H-scan for Detecting Microwave Ablation Zones. ULTRASONIC IMAGING 2023; 45:119-135. [PMID: 36995065 DOI: 10.1177/01617346231162928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The homodyned-K (HK) distribution is a generalized model of envelope statistics whose parameters α (the clustering parameter) and k (the coherent-to-diffuse signal ratio) can be used to monitor the thermal lesions. In this study, we proposed an ultrasound HK contrast-weighted summation (CWS) parametric imaging algorithm based on the H-scan technique and investigated the optimal window side length (WSL) of the HK parameters estimated by the XU estimator (an estimation method based on the first moment of the intensity and two log-moments, which was used in the proposed algorithm) through phantom simulations. H-scan diversified ultrasonic backscattered signals into low- and high-frequency passbands. After envelope detection and HK parameter estimation for each frequency band, the α and k parametric maps were obtained, respectively. According to the contrast between the target region and background, the (α or k) parametric maps of the dual-frequency band were weighted and summed, and then the CWS images were yielded by pseudo-color imaging. The proposed HK CWS parametric imaging algorithm was used to detect the microwave ablation coagulation zones of porcine liver ex vivo under different powers and treatment durations. The performance of the proposed algorithm was compared with that of the conventional HK parametric imaging and frequency diversity and compounding Nakagami imaging algorithms. For two-dimensional HK parametric imaging, it was found that a WSL equal to 4 pulse lengths of the transducer was sufficient for estimating the α and k parameters in terms of both parameter estimation stability and parametric imaging resolution. The HK CWS parametric imaging provided an improved contrast-to-noise ratio over conventional HK parametric imaging, and the HK αcws parametric imaging achieved the best accuracy and Dice score of coagulation zone detection.
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Affiliation(s)
- Sinan Li
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Zhuhuang Zhou
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Shuicai Wu
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Weiwei Wu
- College of Biomedical Engineering, Capital Medical University, Beijing, China
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Li S, Zhou Z, Wu S, Wu W. A Review of Quantitative Ultrasound-Based Approaches to Thermometry and Ablation Zone Identification Over the Past Decade. ULTRASONIC IMAGING 2022; 44:213-228. [PMID: 35993226 DOI: 10.1177/01617346221120069] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Percutaneous thermal therapy is an important clinical treatment method for some solid tumors. It is critical to use effective image visualization techniques to monitor the therapy process in real time because precise control of the therapeutic zone directly affects the prognosis of tumor treatment. Ultrasound is used in thermal therapy monitoring because of its real-time, non-invasive, non-ionizing radiation, and low-cost characteristics. This paper presents a review of nine quantitative ultrasound-based methods for thermal therapy monitoring and their advances over the last decade since 2011. These methods were analyzed and compared with respect to two applications: ultrasonic thermometry and ablation zone identification. The advantages and limitations of these methods were compared and discussed, and future developments were suggested.
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Affiliation(s)
- Sinan Li
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Zhuhuang Zhou
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Shuicai Wu
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Weiwei Wu
- College of Biomedical Engineering, Capital Medical University, Beijing, China
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Li S, Tsui PH, Song S, Wu W, Zhou Z, Wu S. Detection of microwave ablation coagulation areas using ultrasound Nakagami imaging based on Gaussian pyramid decomposition: A feasibility study. ULTRASONICS 2022; 124:106758. [PMID: 35617777 DOI: 10.1016/j.ultras.2022.106758] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 03/14/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
In this paper, we explored the feasibility of using ultrasound Nakagami-m parametric imaging based on Gaussian pyramid decomposition (GPD) to detect microwave ablation coagulation areas. Monte Carlo simulation and phantom simulation results demonstrated that a 2-layer GPD model was sufficient to achieve the same m parameter estimation accuracy, smoothness and resolution as 3-layer and 4-layer. The performances of GPD, moment-based estimator (MBE) and window-modulated compounding (WMC) algorithms were compared in terms of parameter estimation, smoothness, resolution and contrast-to-noise (CNR). Results showed that the m parameter estimation obtained by GPD algorithm was better than that of MBE and WMC algorithms except the small window size (27 × 5). When using a window size of >3 pulse lengths, GPD algorithm could achieve better smoothness and CNR than MBE and WMC algorithms, but there was a certain loss of axial resolution. The computation time of GPD algorithm was less than that of WMC algorithm, while about 2.24 times that of MBE algorithm. Experimental results of porcine liver microwave ablation ex vivo (n = 20) illustrated that the average areas under the operating characteristic curve (AUCs) of Nakagami mGPD, mMBE and mWMC parametric imaging and homodyned-K (HK) α and k parametric imaging to detect coagulation areas were significantly improved by polynomial approximation (PAX). Kruskal-Wallis test showed that the accuracy of coagulation area detection obtained by PAX imaging of mGPD parameter had no significant difference with that of mMBE, mWMC, HK_α and HK_k parameters. This preliminary study suggested that Nakagami imaging based on GPD algorithm may have the potential to detect microwave ablation coagulation areas.
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Affiliation(s)
- Sinan Li
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Institute for Radiological Research, Chang Gung University, Taoyuan, Taiwan; Division of Pediatric Gastroenterology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Shuang Song
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Weiwei Wu
- College of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Zhuhuang Zhou
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China.
| | - Shuicai Wu
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China.
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Ghahramani Z E, Grimm PD, Eary KJ, Swearengen MP, Dayavansha EGSK, Mast TD. Three-dimensional echo decorrelation monitoring of radiofrequency ablation in ex vivo bovine liver. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 151:3907. [PMID: 35778168 PMCID: PMC9187351 DOI: 10.1121/10.0011641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 05/14/2022] [Accepted: 05/23/2022] [Indexed: 06/03/2023]
Abstract
Three-dimensional (3D) echo decorrelation imaging was investigated for monitoring radiofrequency ablation (RFA) in ex vivo bovine liver. RFA experiments (N = 14) were imaged by 3D ultrasound using a matrix array, with in-phase and quadrature complex echo volumes acquired about every 11 s. Tissue specimens were then frozen at -80 °C, sectioned, and semi-automatically segmented. Receiver operating characteristic (ROC) curves were constructed for assessing ablation prediction performance of 3D echo decorrelation with three potential normalization approaches, as well as 3D integrated backscatter (IBS). ROC analysis indicated that 3D echo decorrelation imaging is potentially a good predictor of local RFA, with the best prediction performance observed for globally normalized decorrelation. Tissue temperatures, recorded by four thermocouples integrated into the RFA probe, showed good correspondence with spatially averaged decorrelation and statistically significant but weak correlation with measured echo decorrelation at the same spatial locations. In tests predicting ablation zones using a weighted K-means clustering approach, echo decorrelation performed better than IBS, with smaller root mean square volume errors and higher Dice coefficients relative to measured ablation zones. These results suggest that 3D echo decorrelation and IBS imaging are capable of real-time monitoring of thermal ablation, with potential application to clinical treatment of liver tumors.
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Affiliation(s)
- E Ghahramani Z
- Department of Biomedical Engineering, University of Cincinnati, Ohio 45267-0586, USA
| | - P D Grimm
- Department of Biomedical Engineering, University of Cincinnati, Ohio 45267-0586, USA
| | - K J Eary
- Department of Biomedical Engineering, University of Cincinnati, Ohio 45267-0586, USA
| | - M P Swearengen
- Department of Biomedical Engineering, University of Cincinnati, Ohio 45267-0586, USA
| | | | - T D Mast
- Department of Biomedical Engineering, University of Cincinnati, Ohio 45267-0586, USA
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Li X, Jia X, Shen T, Wang M, Yang G, Wang H, Sun Q, Wan M, Zhang S. Ultrasound Entropy Imaging for Detection and Monitoring of Thermal Lesion During Microwave Ablation of Liver. IEEE J Biomed Health Inform 2022; 26:4056-4066. [PMID: 35417359 DOI: 10.1109/jbhi.2022.3167252] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Ultrasonic B-mode imaging offers non-invasive and real-time monitoring of thermal ablation treatment in clinical use, however it faces challenges of moderate lesion-normal contrast and detection accuracy. Quantitative ultrasound imaging techniques have been proposed as promising tools to evaluate the microstructure of ablated tissue. In this study, we introduced Shannon entropy, a non-model based statistical measurement of disorder, to quantitatively detect and monitor microwave-induced ablation in porcine livers. Performance of typical Shannon entropy (TSE), weighted Shannon entropy (WSE), and horizontally normalized Shannon entropy (hNSE) were explored and compared with conventional B-mode imaging. TSE estimated from non-normalized probability distribution histograms was found to have insufficient discernibility of different disorder of data. WSE that improves from TSE by adding signal amplitudes as weights obtained area under receiver operating characteristic (AUROC) curve of 0.895, whereas it underestimated the periphery of lesion region. hNSE provided superior ablated area prediction with the correlation coefficient of 0.90 against ground truth, AUROC of 0.868, and remarkable lesion-normal contrast with contrast-to-noise ratio of 5.86 which was significantly higher than other imaging methods. Data distributions shown in horizontally normalized probability distribution histograms indicated that the disorder of backscattered envelope signal from ablated region increased as treatment went on. These findings suggest that hNSE imaging could be a promising technique to assist ultrasound guided percutaneous thermal ablation.
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Radiofrequency Ablation for Liver: Comparison between Expert Eye and Hyperspectral Imaging Assessment. Photodiagnosis Photodyn Ther 2021; 37:102699. [PMID: 34942401 DOI: 10.1016/j.pdpdt.2021.102699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 12/14/2021] [Accepted: 12/17/2021] [Indexed: 11/27/2022]
Abstract
Liver/hepatic cancer (HC) is a disease that roughly afflicts 10% of cancer patients worldwide. HC is in charge of the death of 0.8 million patients on the earth. Multiple approaches, including thermal ablation, target the treatment of HC. In this study, we investigated radiofrequency (RF) ablation. Expert clinicians' visual assessment (VA) dominantly evaluated the outcome of ablation. Inattentively, the disfavors of VA are being subjective and eye-acuity dependent. In support, we propose hyperspectral imaging (HSI) for objective assessment of liver ablation. To verify our proposal, we computed the ablated liver area using VA and HSI. Unfortunately, HSI is a time-intensive technique. To make it less intensive, we present a way of reducing data analysis time. Saving time permits medical decisions, likewise continue or stop RF ablation, to be taken safer and faster. The way to reduce the time for HSI data analysis depends on narrowing the spectral bands of interest to only the most relevant ones to liver chromophores. Liver chromophores change in concentration because of thermal ablation. VA hardly senses these changes, however, HSI does it. Ultimately, the spectral band centered at 630 nm is optimal for objectively support RF ablation decision-makers.
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Karunakaran CP, Burgess MT, Rao MB, Holland CK, Mast TD. Effect of Overpressure on Acoustic Emissions and Treated Tissue Histology in ex Vivo Bulk Ultrasound Ablation. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:2360-2376. [PMID: 34023187 PMCID: PMC8243850 DOI: 10.1016/j.ultrasmedbio.2021.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 04/08/2021] [Accepted: 04/11/2021] [Indexed: 06/12/2023]
Abstract
Bulk ultrasound ablation is a thermal therapy approach in which tissue is heated by unfocused or weakly focused sonication (average intensities on the order of 100 W/cm2) to achieve coagulative necrosis within a few minutes exposure time. Assessing the role of bubble activity, including acoustic cavitation and tissue vaporization, in bulk ultrasound ablation may help in making bulk ultrasound ablation safer and more effective for clinical applications. Here, two series of ex vivo ablation trials were conducted to investigate the role of bubble activity and tissue vaporization in bulk ultrasound ablation. Fresh bovine liver tissue was ablated with unfocused, continuous-wave ultrasound using ultrasound image-ablate arrays sonicating at 31 W/cm2 (0.9 MPa amplitude) for either 20 min at a frequency of 3.1 MHz or 10 min at 4.8 MHz. Tissue specimens were maintained at a static overpressure of either 0.52 or 1.2 MPa to suppress bubble activity and tissue vaporization or at atmospheric pressure for control groups. A passive cavitation detector was used to record subharmonic (1.55 or 2.4 MHz), broadband (1.2-1.5 MHz) and low-frequency (5-20 kHz) acoustic emissions. Treated tissue was stained with 2% triphenyl tetrazolium chloride to evaluate thermal lesion dimensions. Subharmonic emissions were significantly reduced in overpressure groups compared with control groups. Correlations observed between acoustic emissions and lesion dimensions were significant and positive for the 3.1-MHz series, but significant and negative for the 4.8-MHz series. The results indicate that for bulk ultrasound ablation, where both acoustic cavitation and tissue vaporization are possible, bubble activity can enhance ablation in the absence of tissue vaporization, but can reduce thermal lesion dimensions in the presence of vaporization.
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Affiliation(s)
| | - Mark T Burgess
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Marepalli B Rao
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA; Department of Environmental Health, University of Cincinnati, Cincinnati, Ohio, USA
| | - Christy K Holland
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA; Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, Ohio, USA
| | - T Douglas Mast
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA; Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, Ohio, USA.
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Wang D, Adams MS, Jones PD, Liu D, Burdette EC, Diederich CJ. High contrast ultrasonic method with multi-spatiotemporal compounding for monitoring catheter-based ultrasound thermal therapy: Development and Ex Vivo Evaluations. IEEE Trans Biomed Eng 2021; 68:3131-3141. [PMID: 33755552 DOI: 10.1109/tbme.2021.3067910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Changes in ultrasound backscatter energy (CBE) imaging can monitor thermal therapy. Catheter-based ultrasound (CBUS) can treat deep tumors with precise spatial control of energy deposition and ablation zones, of which CBE estimation can be limited by low contrast and robustness due to small or inconsistent changes in ultrasound data. This study develops a multi-spatiotemporal compounding CBE (MST-CBE) imaging approach for monitoring specific to CBUS thermal therapy. METHODS Ex vivo thermal ablations were performed with stereotactic positioning of a 180 directional CBUS applicator, temperature monitoring probes, endorectal US probe, and subsequent lesion sectioning and measurement. Five frames of raw radiofrequency data were acquired throughout in 15s intervals. Using window-by-window estimation methods, absolute and positive components of MST-CBE images at each point were obtained by the compounding ratio of squared envelope data within an increasing spatial size in each short-time window. RESULTS Compared with conventional US, Nakagami, and CBE imaging, the detection contrast and robustness quantified by tissue-modification-ratio improved by 37.24.7 (p<0.001), 37.55.2 (p<0.001), and 6.44.0 dB (p<0.05) in the MST-CBE imaging, respectively. Correlation coefficient and bias between cross-sectional dimensions of the ablation zones measured in tissue sections and estimated from MST-CBE were up to 0.91 (p<0.001) and -0.02 mm2, respectively. CONCLUSION The MST-CBE approach can monitor the detailed changes within target tissues and effectively characterize the dimensions of the ablation zone during CBUS energy deposition. SIGNIFICANCE The MST-CBE approach could be practical for improved accuracy and contrast of monitoring and evaluation for CBUS thermal therapy.
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Song S, Tsui PH, Wu W, Wu S, Zhou Z. Monitoring microwave ablation using ultrasound homodyned K imaging based on the noise-assisted correlation algorithm: An ex vivo study. ULTRASONICS 2021; 110:106287. [PMID: 33091652 DOI: 10.1016/j.ultras.2020.106287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 09/15/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
In this paper, we proposed ultrasound homodyned K (HK) imaging based on the noise-assisted correlation algorithm (NCA) for monitoring microwave ablation of porcine liver ex vivo. The NCA-based HK (αNCA and kNCA) imaging was compared with NCA-based Nakagami (mNCA) imaging and NCA-based cumulative echo decorrelation (CEDNCA) imaging. Backscattered ultrasound radiofrequency signals of porcine liver ex vivo during and after the heating of microwave ablation were collected (n = 15), which were processed for constructing B-mode imaging, NCA-based HK imaging, NCA-based Nakagami imaging, and NCA-based CED imaging. To quantitatively evaluate the final coagulation zone, the polynomial approximation (PAX) technique was applied. The accuracy of detecting coagulation area with αNCA, kNCA, mNCA, and CEDNCA parametric imaging was evaluated by comparing the PAX imaging with the gross pathology. The receiver operating characteristic (ROC) curve was used to further evaluate the performance of the three quantitative ultrasound imaging methods for detecting the coagulation zone. Experimental results showed that the average accuracies of αNCA, kNCA, mNCA, and CEDNCA parametric imaging combined with PAX imaging were 89.6%, 83.25%, 89.23%, and 91.6%, respectively. The average areas under the ROC curve (AUROCs) of αNCA, kNCA, mNCA, and CEDNCA parametric imaging were 0.83, 0.77, 0.83, and 0.86, respectively. The proposed NCA-based HK imaging may be used as a new method for monitoring microwave ablation.
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Affiliation(s)
- Shuang Song
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Weiwei Wu
- College of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Shuicai Wu
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China.
| | - Zhuhuang Zhou
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China.
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Cox MT, Abbass MA, Mast TD. Numerical analysis of three-dimensional echo decorrelation imaging. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:EL478. [PMID: 32611173 PMCID: PMC7275868 DOI: 10.1121/10.0001334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A numerical model for three-dimensional echo decorrelation imaging, a pulse-echo ultrasound method applicable to thermal ablation monitoring, is presented. Beam patterns for steered transmit and receive array apertures are combined with a three-dimensional numerical tissue model to yield beamformed scan lines in a pyramidal configuration, volumetric B-mode images, and spatial maps of normalized decorrelation between sequential image volumes. Simulated three-dimensional echo decorrelation images of random media are analyzed as estimators of local tissue reflectivity decoherence, mimicking thermal ablation effects. The estimation error is analyzed as a function of correlation window size, scan line density, and ensemble averaging of decorrelation maps.
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Affiliation(s)
- Michael T Cox
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45267, , ,
| | - Mohamed A Abbass
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45267, , ,
| | - T Douglas Mast
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45267, , ,
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Abbass MA, Ahmad SA, Mahalingam N, Krothapalli KS, Masterson JA, Rao MB, Barthe PG, Mast TD. In vivo ultrasound thermal ablation control using echo decorrelation imaging in rabbit liver and VX2 tumor. PLoS One 2019; 14:e0226001. [PMID: 31805129 PMCID: PMC6894854 DOI: 10.1371/journal.pone.0226001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 11/18/2019] [Indexed: 12/21/2022] Open
Abstract
The utility of echo decorrelation imaging feedback for real-time control of in vivo ultrasound thermal ablation was assessed in rabbit liver with VX2 tumor. High-intensity focused ultrasound (HIFU) and unfocused (bulk) ablation were performed using 5 MHz linear image-ablate arrays. Treatments comprised up to nine lower-power sonications, followed by up to nine higher-power sonications, ceasing when the average cumulative echo decorrelation within a control region of interest exceeded a predefined threshold (- 2.3, log10-scaled echo decorrelation per millisecond, corresponding to 90% specificity for tumor ablation prediction in previous in vivo experiments). This threshold was exceeded in all cases for both HIFU (N = 12) and bulk (N = 8) ablation. Controlled HIFU trials achieved a significantly higher average ablation rate compared to comparable ablation trials without image-based control, reported previously. Both controlled HIFU and bulk ablation trials required significantly less treatment time than these previous uncontrolled trials. Prediction of local liver and VX2 tumor ablation using echo decorrelation was tested using receiver operator characteristic curve analysis, showing prediction capability statistically equivalent to uncontrolled trials. Compared to uncontrolled trials, controlled trials resulted in smaller thermal ablation regions and higher contrast between echo decorrelation in treated vs. untreated regions. These results indicate that control using echo decorrelation imaging may reduce treatment duration and increase treatment reliability for in vivo thermal ablation.
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Affiliation(s)
- Mohamed A. Abbass
- Dept of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Syed A. Ahmad
- Dept of Surgery, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Neeraja Mahalingam
- Dept of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - K. Sameer Krothapalli
- Dept of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Jack A. Masterson
- Dept of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Marepalli B. Rao
- Dept of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
- Dept of Environmental Health, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Peter G. Barthe
- Guided Therapy Systems/Ardent Sound, Mesa, Arizona, United States of America
| | - T. Douglas Mast
- Dept of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
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13
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Liu D, Brace CL. Evaluation of tissue deformation during radiofrequency and microwave ablation procedures: Influence of output energy delivery. Med Phys 2019; 46:4127-4134. [PMID: 31260115 DOI: 10.1002/mp.13688] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 06/07/2019] [Accepted: 06/22/2019] [Indexed: 12/12/2022] Open
Abstract
PURPOSE The purpose of this study was to quantitatively analyze tissue deformation during radiofrequency (RF) and microwave ablation for varying output energy levels. METHODS A total of 46 fiducial markers which were classified into outer, middle, and inner lines were positioned into a single plane around an RF or microwave ablation applicator in each ex vivo bovine liver sample (8 cm × 6 cm × 4 cm, n = 18). Radiofrequency (500 kHz; ~35 W average) or microwave (2.4 GHz; 50-100 W output, ~35-70 W delivered) ablation was performed for 10 min (n = 4-6 each setting). CT images were acquired over the entire liver volume every 15 s. Principle strain magnitude and direction were determined from fiducial marker displacement. Normal and shear strain were then calculated such that negative strain denoted contraction and positive strain denoted expansion. Temporal variations, the final magnitudes, and angles of the strain were compared across energy delivery settings, using one-way ANOVA with post hoc Tukey's tests. RESULTS On average, tissue strain rates peak at around 1 min and decayed exponentially over time. No evidence of tissue expansion was observed. The tissue strains from RF and 50 W, 75 W, and 100 W microwave ablation at 10 min were -8.5%, -38.9%, -54.4%, and -65.7%, respectively, from the inner region and -3.6%, -23.7%, -41.8%, and -44.3%, respectively, from the outer region. Negative strain magnitude was positively correlated to energy delivery in the inner region (Spearman's ρ = -0.99). Microwaves at higher powers (75-100 W) induced significantly more strain than at lower power (50 W) or after RF ablation (P < 0.01). Principal strain angles ranged from 0.8° to -8.1°, indicating that tissue deformed more in the direction transverse to the applicator than along the direction of the applicator. CONCLUSIONS The influence of output energy on tissue deformation during RF and microwave ablation was analyzed. Microwave ablation created significantly greater contraction than RF ablation with similar energy delivery. During microwave ablation, more contraction was noted at higher power levels and in proximity to the antenna. Contraction primarily transverse to the antenna produces ablation zones that are more elongated than the original tissue volume.
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Affiliation(s)
- Dong Liu
- Departments of Radiology, Biomedical Engineering, University of Wisconsin, Madison, WI, 53705, USA
| | - Christopher L Brace
- Departments of Radiology, Biomedical Engineering, University of Wisconsin, Madison, WI, 53705, USA
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Zhou Z, Wang Y, Song S, Wu W, Wu S, Tsui PH. Monitoring Microwave Ablation Using Ultrasound Echo Decorrelation Imaging: An ex vivo Study. SENSORS (BASEL, SWITZERLAND) 2019; 19:E977. [PMID: 30823609 PMCID: PMC6412341 DOI: 10.3390/s19040977] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 02/17/2019] [Accepted: 02/21/2019] [Indexed: 12/19/2022]
Abstract
In this study, a microwave-induced ablation zone (thermal lesion) monitoring method based on ultrasound echo decorrelation imaging was proposed. A total of 15 cases of ex vivo porcine liver microwave ablation (MWA) experiments were carried out. Ultrasound radiofrequency (RF) signals at different times during MWA were acquired using a commercial clinical ultrasound scanner with a 7.5-MHz linear-array transducer. Instantaneous and cumulative echo decorrelation images of two adjacent frames of RF data were calculated. Polynomial approximation images were obtained on the basis of the thresholded cumulative echo decorrelation images. Experimental results showed that the instantaneous echo decorrelation images outperformed conventional B-mode images in monitoring microwave-induced thermal lesions. Using gross pathology measurements as the reference standard, the estimation of thermal lesions using the polynomial approximation images yielded an average accuracy of 88.60%. We concluded that instantaneous ultrasound echo decorrelation imaging is capable of monitoring the change of thermal lesions during MWA, and cumulative ultrasound echo decorrelation imaging and polynomial approximation imaging are feasible for quantitatively depicting thermal lesions.
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Affiliation(s)
- Zhuhuang Zhou
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Yue Wang
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Shuang Song
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Weiwei Wu
- College of Biomedical Engineering, Capital Medical University, Beijing 100054, China.
| | - Shuicai Wu
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
- Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan 33302, Taiwan.
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan 33302, Taiwan.
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15
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Zhang L, Li Q, Wang CY, Tsui PH. Ultrasound single-phase CBE imaging for monitoring radiofrequency ablation. Int J Hyperthermia 2018; 35:548-558. [PMID: 30354749 DOI: 10.1080/02656736.2018.1512160] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Radiofrequency (RF) ablation (RFA) is the most commonly used minimally invasive procedure for thermal ablation of liver tumors. Ultrasound not only provides real-time feedback of the electrode location for RFA guidance but also enables visualization of the tissue temperature. Changes in backscattered energy (CBE) have been widely applied to ultrasound temperature imaging for assessing thermal ablation. Pilot studies have revealed that significant shadowing features appear in CBE imaging and are caused by the electrode and RFA-induced gas bubbles. To resolve this problem, the current study proposed ultrasound single-phase CBE imaging based on positive CBE values. An in vitro model with tissue samples derived from the porcine tenderloin was used to validate the proposed method. During RFA with various electrode lengths, ultrasound scans of tissue samples were obtained using a clinical ultrasound scanner equipped with a convex array transducer of 3 MHz. Raw image data comprising 256 scan lines of backscattered RF signals were acquired for B-mode, conventional CBE, and single-phase CBE imaging by using the proposed algorithmic scheme. The ablation sizes estimated using CBE imaging and gross examinations were compared to calculate the correlation coefficient. The experimental results indicated that single-phase CBE imaging largely suppressed artificial CBE information in the shadowed region. Moreover, compared with conventional CBE imaging, single-phase CBE imaging provided a more accurate estimation of ablation sizes (the correlation coefficient was higher than 0.8).
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Affiliation(s)
- Lin Zhang
- a School of Microelectronics , Tianjin University , Tianjin , China
| | - Qiang Li
- a School of Microelectronics , Tianjin University , Tianjin , China
| | - Chiao-Yin Wang
- b Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University , Taoyuan , Taiwan.,c Department of Medical Imaging and Radiological Sciences , College of Medicine, Chang Gung University , Taoyuan , Taiwan
| | - Po-Hsiang Tsui
- c Department of Medical Imaging and Radiological Sciences , College of Medicine, Chang Gung University , Taoyuan , Taiwan.,d Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou , Taoyuan , Taiwan.,e Department of Medical Imaging and Intervention , Chang Gung Memorial Hospital at Linkou , Taoyuan , Taiwan
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16
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Abbass MA, Garbo AJ, Mahalingam N, Killin JK, Mast TD. Optimized Echo Decorrelation Imaging Feedback for Bulk Ultrasound Ablation Control. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:1743-1755. [PMID: 29994657 PMCID: PMC6294441 DOI: 10.1109/tuffc.2018.2847599] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Feasibility of controlling bulk ultrasound (US) thermal ablation using echo decorrelation imaging was investigated in ex vivo bovine liver. The first of two ablation and control procedures used a sequence of constant-intensity sonication cycles, ceased when the minimum echo decorrelation within a control region of interest (ROI) exceeded a predetermined threshold. The second procedure used a variable-intensity sonication sequence, with spatially averaged decorrelation as the stopping criterion. US exposures and echo decorrelation imaging were performed by a linear image-ablate array. Based on preliminary experiments, control ROIs and thresholds for the minimum-decorrelation and average-decorrelation criteria were specified. Controlled trials for the minimum-decorrelation and average-decorrelation criteria were compared with uncontrolled trials employing 9 or 18 cycles of matching sonication sequences. Lesion dimensions, treatment times, ablation rates, and areas under receiver operating characteristic curves were statistically compared. Successfully controlled trials using both criteria required significantly shorter treatment times than corresponding 18-cycle treatments, with better ablation prediction performance than uncontrolled 9-cycle and 18-cycle treatments. Either control approach resulted in greater ablation rate than corresponding 9-cycle or 18-cycle uncontrolled approaches. A post hoc analysis studied the effect of exchanging control criteria between the two series of controlled experiments. For either group, the average time needed to exceed the alternative decorrelation threshold approximately matched the average duration of successfully controlled experimental trials. These results indicate that either approach, using minimum-decorrelation or average-decorrelation criteria, is feasible for control of bulk US ablation. In addition, use of a variable-intensity sonication sequence for bulk US thermal ablation can result in larger ablated regions compared to constant-intensity sonication sequences.
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17
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Zhang S, Xu R, Shang S, Han Y, Liu S, Xu T, Gu C, Zhu X, Niu G, Wan M. In vivo monitoring of microwave ablation in a porcine model using ultrasonic differential attenuation coefficient intercept imaging. Int J Hyperthermia 2018; 34:1157-1170. [DOI: 10.1080/02656736.2018.1437477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Siyuan Zhang
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
| | - Ranxiang Xu
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
| | - Shaoqiang Shang
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
| | - Yuqiang Han
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
| | - Sihao Liu
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
| | - Tianqi Xu
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
| | - Chunming Gu
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
| | - Xingguang Zhu
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
- Medical Engineering Division, Beijing HuiLongGuan Hospital, Beijing, People's Republic of China
| | - Gang Niu
- Department of Radiology, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, People’s Republic of China
| | - Mingxi Wan
- Department of Biomedical Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, People’s Republic of China
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18
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Abbass MA, Killin JK, Mahalingam N, Hooi FM, Barthe PG, Mast TD. Real-Time Spatiotemporal Control of High-Intensity Focused Ultrasound Thermal Ablation Using Echo Decorrelation Imaging in ex Vivo Bovine Liver. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:199-213. [PMID: 29074273 PMCID: PMC5712268 DOI: 10.1016/j.ultrasmedbio.2017.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 08/28/2017] [Accepted: 09/07/2017] [Indexed: 05/05/2023]
Abstract
The ability to control high-intensity focused ultrasound (HIFU) thermal ablation using echo decorrelation imaging feedback was evaluated in ex vivo bovine liver. Sonications were automatically ceased when the minimum cumulative echo decorrelation within the region of interest exceeded an ablation control threshold, determined from preliminary experiments as -2.7 (log-scaled decorrelation per millisecond), corresponding to 90% specificity for local ablation prediction. Controlled HIFU thermal ablation experiments were compared with uncontrolled experiments employing two, five or nine sonication cycles. Means and standard errors of the lesion width, area and depth, as well as receiver operating characteristic curves testing ablation prediction performance, were computed for each group. Controlled trials exhibited significantly smaller average lesion area, width and treatment time than five-cycle or nine-cycle uncontrolled trials and also had significantly greater prediction capability than two-cycle uncontrolled trials. These results suggest echo decorrelation imaging is an effective approach to real-time HIFU ablation control.
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Affiliation(s)
- Mohamed A Abbass
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jakob K Killin
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | | | - Fong Ming Hooi
- Ultrasound Division, Siemens Healthcare, Issaquah, Washington, USA
| | | | - T Douglas Mast
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA.
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19
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Perlman O, Weitz IS, Azhari H. Target visualisation and microwave hyperthermia monitoring using nanoparticle-enhanced transmission ultrasound (NETUS). Int J Hyperthermia 2017; 34:773-785. [DOI: 10.1080/02656736.2017.1378386] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Or Perlman
- Department of Biomedical Engineering, Technion – Israel Institute of Technology, Haifa, Israel
| | - Iris S. Weitz
- Department of Biotechnology Engineering, ORT Braude College, Karmiel, Israel
| | - Haim Azhari
- Department of Biomedical Engineering, Technion – Israel Institute of Technology, Haifa, Israel
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20
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Abstract
Radiofrequency ablation (RFA) has been widely used as an alternative treatment modality for liver tumors. Monitoring the temperature distribution in the tissue during RFA is required to assess the thermal dosage. Ultrasound temperature imaging based on the detection of echo time shifts has received the most attention in the past decade. The coefficient k, connecting the temperature change and the echo time shift, is a medium-dependent parameter used to describe the confounding effects of changes in the speed of sound and thermal expansion as temperature increases. The current algorithm of temperature estimate based on echo time shift detection typically uses a constant k, resulting in estimation errors when ablation temperatures are higher than 50°C. This study proposes an adaptive-k algorithm that enables the automatic adjustment of the coefficient k during ultrasound temperature monitoring of RFA. To verify the proposed algorithm, RFA experiments on in vitro porcine liver samples (total n = 15) were performed using ablation powers of 10, 15, and 20 W. During RFA, a clinical ultrasound system equipped with a 7.5-MHz linear transducer was used to collect backscattered signals for ultrasound temperature imaging using the constant- and adaptive-k algorithms. Concurrently, an infrared imaging system and thermocouples were used to measure surface temperature distribution of the sample and internal ablation temperatures for comparisons with ultrasound estimates. Experimental results demonstrated that the proposed adaptive-k method improved the performance in visualizing the temperature distribution. In particular, the estimation errors were also reduced even when the temperature of the tissue is higher than 50°C. The proposed adaptive-k ultrasound temperature imaging strategy has potential to serve as a thermal dosage evaluation tool for monitoring high-temperature RFA.
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21
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Liu YD, Li Q, Zhou Z, Yeah YW, Chang CC, Lee CY, Tsui PH. Adaptive ultrasound temperature imaging for monitoring radiofrequency ablation. PLoS One 2017; 12:e0182457. [PMID: 28837584 PMCID: PMC5570358 DOI: 10.1371/journal.pone.0182457] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/18/2017] [Indexed: 12/31/2022] Open
Abstract
Radiofrequency ablation (RFA) has been widely used as an alternative treatment modality for liver tumors. Monitoring the temperature distribution in the tissue during RFA is required to assess the thermal dosage. Ultrasound temperature imaging based on the detection of echo time shifts has received the most attention in the past decade. The coefficient k, connecting the temperature change and the echo time shift, is a medium-dependent parameter used to describe the confounding effects of changes in the speed of sound and thermal expansion as temperature increases. The current algorithm of temperature estimate based on echo time shift detection typically uses a constant k, resulting in estimation errors when ablation temperatures are higher than 50°C. This study proposes an adaptive-k algorithm that enables the automatic adjustment of the coefficient k during ultrasound temperature monitoring of RFA. To verify the proposed algorithm, RFA experiments on in vitro porcine liver samples (total n = 15) were performed using ablation powers of 10, 15, and 20 W. During RFA, a clinical ultrasound system equipped with a 7.5-MHz linear transducer was used to collect backscattered signals for ultrasound temperature imaging using the constant- and adaptive-k algorithms. Concurrently, an infrared imaging system and thermocouples were used to measure surface temperature distribution of the sample and internal ablation temperatures for comparisons with ultrasound estimates. Experimental results demonstrated that the proposed adaptive-k method improved the performance in visualizing the temperature distribution. In particular, the estimation errors were also reduced even when the temperature of the tissue is higher than 50°C. The proposed adaptive-k ultrasound temperature imaging strategy has potential to serve as a thermal dosage evaluation tool for monitoring high-temperature RFA.
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Affiliation(s)
- Yi-Da Liu
- School of Electronic Information Engineering, Tianjin University, Tianjin, China
| | - Qiang Li
- School of Electronic Information Engineering, Tianjin University, Tianjin, China
| | - Zhuhuang Zhou
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
- Faculty of Information Technology, Beijing University of Technology, Beijing, China
| | - Yao-Wen Yeah
- Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan
| | - Chien-Cheng Chang
- Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan
- * E-mail: (PHT); (CCC)
| | - Chia-Yen Lee
- Department of Electrical Engineering, National United University, Miao-Li, Taiwan
| | - Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- * E-mail: (PHT); (CCC)
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22
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Vannacci E, Granchi S, Breschi L, Biagi E. A feasibility study of a novel spectral method using radiofrequency ultrasound data for monitoring laser tissue ablation. ULTRASONICS 2017; 78:83-95. [PMID: 28324777 DOI: 10.1016/j.ultras.2017.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 02/21/2017] [Accepted: 03/03/2017] [Indexed: 06/06/2023]
Abstract
This paper presents preliminary results of a new non-invasive ultrasound monitoring method called TUV (Thermotherapy Ultrasonic View) able to investigate structural tissue modifications caused by minimally invasive percutaneous laser ablation. The method, based on the spectral analysis of the raw ultrasound radiofrequency signal, develops spectral parameters in a multidimensional space and its N dimensions are represented by the central frequencies of the sub bands the signal spectrum is decomposed into. Signal processing has been performed on the data related to 7 laser treatments performed on 4 samples of removed prostatic glands which underwent laser ablation at power of 3W, 4W and 5W and energy of 1800J. In this preliminary study, clusters of these parameters, referred to tissue areas at different distances from the light laser source, modified their shape and position in different ways, during ablation treatment. TUV results have been represented by a chromatic code superimposed to the corresponding ultrasound conventional image, in order to highlight the alteration intensities occurred in the ablated tissue. Resulting images of ablated area have been compared to histological specimens to evaluate the degree of similarity between them by means of Dice and Jaccard coefficients.
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Affiliation(s)
- Enrico Vannacci
- Department of Information Engineering (DINFO), University of Florence, Via Santa Marta 3, 50139 Florence, Italy
| | - Simona Granchi
- Department of Information Engineering (DINFO), University of Florence, Via Santa Marta 3, 50139 Florence, Italy.
| | | | - Elena Biagi
- Department of Information Engineering (DINFO), University of Florence, Via Santa Marta 3, 50139 Florence, Italy
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23
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Fosnight TR, Hooi FM, Keil RD, Ross AP, Subramanian S, Akinyi TG, Killin JK, Barthe PG, Rudich SM, Ahmad SA, Rao MB, Mast TD. Echo Decorrelation Imaging of Rabbit Liver and VX2 Tumor during In Vivo Ultrasound Ablation. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:176-186. [PMID: 27712923 PMCID: PMC5140680 DOI: 10.1016/j.ultrasmedbio.2016.08.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/18/2016] [Accepted: 08/21/2016] [Indexed: 05/05/2023]
Abstract
In open surgical procedures, image-ablate ultrasound arrays performed thermal ablation and imaging on rabbit liver lobes with implanted VX2 tumor. Treatments included unfocused (bulk ultrasound ablation, N = 10) and focused (high-intensity focused ultrasound ablation, N = 13) exposure conditions. Echo decorrelation and integrated backscatter images were formed from pulse-echo data recorded during rest periods after each therapy pulse. Echo decorrelation images were corrected for artifacts using decorrelation measured prior to ablation. Ablation prediction performance was assessed using receiver operating characteristic curves. Results revealed significantly increased echo decorrelation and integrated backscatter in both ablated liver and ablated tumor relative to unablated tissue, with larger differences observed in liver than in tumor. For receiver operating characteristic curves computed from all ablation exposures, both echo decorrelation and integrated backscatter predicted liver and tumor ablation with statistically significant success, and echo decorrelation was significantly better as a predictor of liver ablation. These results indicate echo decorrelation imaging is a successful predictor of local thermal ablation in both normal liver and tumor tissue, with potential for real-time therapy monitoring.
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Affiliation(s)
- Tyler R Fosnight
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Fong Ming Hooi
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Ryan D Keil
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Alexander P Ross
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | | | - Teckla G Akinyi
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jakob K Killin
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | | | | | - Syed A Ahmad
- Surgery, University of Cincinnati, Cincinnati, Ohio, USA
| | - Marepalli B Rao
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA; Environmental Health, University of Cincinnati, Cincinnati, Ohio, USA
| | - T Douglas Mast
- Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA.
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24
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Subramanian S, Schmidt DT, Rao MB, Mast TD. Dependence of ultrasound echo decorrelation on local tissue temperature during ex vivo radiofrequency ablation. Phys Med Biol 2016; 61:2356-71. [PMID: 26943026 DOI: 10.1088/0031-9155/61/6/2356] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
This study investigates echo decorrelation imaging, an ultrasound method for thermal ablation monitoring. The effect of tissue temperature on the mapped echo decorrelation parameter was assessed in radiofrequency ablation experiments performed on ex vivo bovine liver tissue. Echo decorrelation maps were compared with corresponding tissue temperatures simulated using the finite element method. For both echo decorrelation imaging and integrated backscatter imaging, the mapped tissue parameters correlated significantly but weakly with local tissue temperature. Receiver operating characteristic (ROC) curves were used to assess the ability of echo decorrelation and integrated backscatter to predict tissue temperature greater than 40, 60, and 80 °C. Significantly higher area under the ROC curve (AUROC) values were obtained for prediction of tissue temperatures greater than 40, 60, and 80 °C using echo decorrelation imaging (AUROC = 0.871, 0.948 and 0.966) compared to integrated backscatter imaging (AUROC = 0.865, 0.877 and 0.832).
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Affiliation(s)
- Swetha Subramanian
- Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH, USA
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25
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Subramanian S, Mast TD. Optimization of tissue physical parameters for accurate temperature estimation from finite-element simulation of radiofrequency ablation. Phys Med Biol 2015; 60:N345-55. [PMID: 26352462 DOI: 10.1088/0031-9155/60/19/n345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Computational finite element models are commonly used for the simulation of radiofrequency ablation (RFA) treatments. However, the accuracy of these simulations is limited by the lack of precise knowledge of tissue parameters. In this technical note, an inverse solver based on the unscented Kalman filter (UKF) is proposed to optimize values for specific heat, thermal conductivity, and electrical conductivity resulting in accurately simulated temperature elevations. A total of 15 RFA treatments were performed on ex vivo bovine liver tissue. For each RFA treatment, 15 finite-element simulations were performed using a set of deterministically chosen tissue parameters to estimate the mean and variance of the resulting tissue ablation. The UKF was implemented as an inverse solver to recover the specific heat, thermal conductivity, and electrical conductivity corresponding to the measured area of the ablated tissue region, as determined from gross tissue histology. These tissue parameters were then employed in the finite element model to simulate the position- and time-dependent tissue temperature. Results show good agreement between simulated and measured temperature.
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Affiliation(s)
- Swetha Subramanian
- Department of Biomedical, Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45220, USA
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26
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Haworth KJ, Salgaonkar VA, Corregan NM, Holland CK, Mast TD. Using passive cavitation images to classify high-intensity focused ultrasound lesions. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:2420-34. [PMID: 26051309 PMCID: PMC4526372 DOI: 10.1016/j.ultrasmedbio.2015.04.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 03/31/2015] [Accepted: 04/26/2015] [Indexed: 05/11/2023]
Abstract
Passive cavitation imaging provides spatially resolved monitoring of cavitation emissions. However, the diffraction limit of a linear imaging array results in relatively poor range resolution. Poor range resolution has limited prior analyses of the spatial specificity and sensitivity of passive cavitation imaging in predicting thermal lesion formation. In this study, this limitation is overcome by orienting a linear array orthogonal to the high-intensity focused ultrasound propagation direction and performing passive imaging. Fourteen lesions were formed in ex vivo bovine liver samples as a result of 1.1-MHz continuous-wave ultrasound exposure. The lesions were classified as focal, "tadpole" or pre-focal based on their shape and location. Passive cavitation images were beamformed from emissions at the fundamental, harmonic, ultraharmonic and inharmonic frequencies with an established algorithm. Using the area under a receiver operating characteristic curve (AUROC), fundamental, harmonic and ultraharmonic emissions were found to be significant predictors of lesion formation for all lesion types. For both harmonic and ultraharmonic emissions, pre-focal lesions were classified most successfully (AUROC values of 0.87 and 0.88, respectively), followed by tadpole lesions (AUROC values of 0.77 and 0.64, respectively) and focal lesions (AUROC values of 0.65 and 0.60, respectively).
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Affiliation(s)
- Kevin J Haworth
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Biomedical Engineering Program, University of Cincinnati, Cincinnati, Ohio, USA.
| | - Vasant A Salgaonkar
- Biomedical Engineering Program, University of Cincinnati, Cincinnati, Ohio, USA
| | - Nicholas M Corregan
- Biomedical Engineering Program, University of Cincinnati, Cincinnati, Ohio, USA
| | - Christy K Holland
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Biomedical Engineering Program, University of Cincinnati, Cincinnati, Ohio, USA
| | - T Douglas Mast
- Biomedical Engineering Program, University of Cincinnati, Cincinnati, Ohio, USA
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27
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Salgaonkar VA, Diederich CJ. Catheter-based ultrasound technology for image-guided thermal therapy: current technology and applications. Int J Hyperthermia 2015; 31:203-15. [PMID: 25799287 DOI: 10.3109/02656736.2015.1006269] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Catheter-based ultrasound (CBUS) is applied to deliver minimally invasive thermal therapy to solid cancer tumours, benign tissue growth, vascular disease, and tissue remodelling. Compared to other energy modalities used in catheter-based surgical interventions, unique features of ultrasound result in conformable and precise energy delivery with high selectivity, fast treatment times, and larger treatment volumes. We present a concise review of CBUS technology being currently utilized in animal and clinical studies or being developed for future applications. CBUS devices have been categorised into interstitial, endoluminal and endovascular/cardiac applications. Basic applicator designs, site-specific evaluations and possible treatment applications have been discussed in brief. Particular emphasis has been given to ablation studies that incorporate image guidance for applicator placement, therapy monitoring, feedback control, and post-procedure assessment. Examples of devices included here span the entire spectrum of the development cycle from preliminary simulation-based design studies to implementation in clinical investigations. The use of CBUS under image guidance has the potential for significantly improving precision and applicability of thermal therapy delivery.
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Affiliation(s)
- Vasant A Salgaonkar
- Department of Radiation Oncology, University of California , San Francisco, California , USA
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28
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Fite BZ, Wong A, Liu Y, Mahakian LM, Tam SM, Aina O, Hubbard NE, Borowsky A, Cardiff RD, Dumont E, Ferrara KW. Magnetic resonance imaging assessment of effective ablated volume following high intensity focused ultrasound. PLoS One 2015; 10:e0120037. [PMID: 25785992 PMCID: PMC4365027 DOI: 10.1371/journal.pone.0120037] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 01/15/2015] [Indexed: 01/30/2023] Open
Abstract
Under magnetic resonance (MR) guidance, high intensity focused ultrasound (HIFU) is capable of precise and accurate delivery of thermal dose to tissues. Given the excellent soft tissue imaging capabilities of MRI, but the lack of data on the correlation of MRI findings to histology following HIFU, we sought to examine tumor response to HIFU ablation to determine whether there was a correlation between histological findings and common MR imaging protocols in the assessment of the extent of thermal damage. Female FVB mice (n = 34), bearing bilateral neu deletion tumors, were unilaterally insonated under MR guidance, with the contralateral tumor as a control. Between one and five spots (focal size 0.5 × 0.5 × 2.5 mm3) were insonated per tumor with each spot receiving approximately 74.2 J of acoustic energy over a period of 7 seconds. Animals were then imaged on a 7T MR scanner with several protocols. T1 weighted images (with and without gadolinium contrast) were collected in addition to a series of T2 weighted and diffusion weighted images (for later reconstruction into T2 and apparent diffusion coefficient maps), immediately following ablation and at 6, 24, and 48 hours post treatment. Animals were sacrificed at each time point and both insonated/treated and contralateral tumors removed and stained for NADH-diaphorase, caspase 3, or with hematoxylin and eosin (H&E). We found the area of non-enhancement on contrast enhanced T1 weighted imaging immediately post ablation correlated with the region of tissue receiving a thermal dose CEM43 ≥ 240 min. Moreover, while both tumor T2 and apparent diffusion coefficient values changed from pre-ablation values, contrast enhanced T1 weighted images appeared to be more senstive to changes in tissue viability following HIFU ablation.
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Affiliation(s)
- Brett Z. Fite
- Department of Biomedical Engineering, University of California Davis, Davis, CA, 95616, United States of America
| | - Andrew Wong
- Department of Biomedical Engineering, University of California Davis, Davis, CA, 95616, United States of America
| | - Yu Liu
- Department of Biomedical Engineering, University of California Davis, Davis, CA, 95616, United States of America
| | - Lisa M. Mahakian
- Department of Biomedical Engineering, University of California Davis, Davis, CA, 95616, United States of America
| | - Sarah M. Tam
- Department of Biomedical Engineering, University of California Davis, Davis, CA, 95616, United States of America
| | - Olulanu Aina
- Center for Comparative Medicine, University of California Davis, Davis, CA, 95616, United States of America
| | - Neil E. Hubbard
- Center for Comparative Medicine, University of California Davis, Davis, CA, 95616, United States of America
| | - Alexander Borowsky
- Center for Comparative Medicine, University of California Davis, Davis, CA, 95616, United States of America
- Department of Pathology and Laboratory Medicine, School of Medicine, University of California Davis, Davis, CA, 95616, United States of America
| | - Robert D. Cardiff
- Center for Comparative Medicine, University of California Davis, Davis, CA, 95616, United States of America
- Department of Pathology and Laboratory Medicine, School of Medicine, University of California Davis, Davis, CA, 95616, United States of America
| | | | - Katherine W. Ferrara
- Department of Biomedical Engineering, University of California Davis, Davis, CA, 95616, United States of America
- * E-mail:
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Ebbini ES, ter Haar G. Ultrasound-guided therapeutic focused ultrasound: current status and future directions. Int J Hyperthermia 2015; 31:77-89. [PMID: 25614047 DOI: 10.3109/02656736.2014.995238] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
This paper reviews ultrasound imaging methods for the guidance of therapeutic focused ultrasound (USgFUS), with emphasis on real-time preclinical methods. Guidance is interpreted in the broadest sense to include pretreatment planning, siting of the FUS focus, real-time monitoring of FUS-tissue interactions, and real-time control of exposure and damage assessment. The paper begins with an overview and brief historical background of the early methods used for monitoring FUS-tissue interactions. Current imaging methods are described, and discussed in terms of sensitivity and specificity of the localisation of the FUS effects in both therapeutic and sub-therapeutic modes. Thermal and non-thermal effects are considered. These include cavitation-enhanced heating, tissue water boiling and cavitation. Where appropriate, USgFUS methods are compared with similar methods implemented using other guidance modalities, e.g. magnetic resonance imaging. Conclusions are drawn regarding the clinical potential of the various guidance methods, and the feasibility and current status of real-time implementation.
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Affiliation(s)
- Emad S Ebbini
- Electrical and Computer Engineering, University of Minnesota Twin Cities , Minneapolis, Minnesota , USA and
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30
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Abstract
In this review we present the current status of ultrasound thermometry and ablation monitoring, with emphasis on the diverse approaches published in the literature and with an eye on which methods are closest to clinical reality. It is hoped that this review will serve as a guide to the expansion of sonographic methods for treatment monitoring and thermometry since the last brief review in 2007.
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Affiliation(s)
- Matthew A. Lewis
- Department of Radiology, UT Southwestern Medical Center at Dallas
| | - Robert M. Staruch
- Department of Radiology, UT Southwestern Medical Center at Dallas
- Ultrasound Imaging & Interventions, Philips Research North America
| | - Rajiv Chopra
- Department of Radiology, UT Southwestern Medical Center at Dallas
- Advanced Imaging Research Center, UT Southwestern Medical Center at Dallas
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31
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Hooi FM, Nagle A, Subramanian S, Douglas Mast T. Analysis of tissue changes, measurement system effects, and motion artifacts in echo decorrelation imaging. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:585-97. [PMID: 25697993 PMCID: PMC4336259 DOI: 10.1121/1.4906580] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Echo decorrelation imaging, a method for mapping ablation-induced ultrasound echo changes, is analyzed. Local echo decorrelation is shown to approximate the decoherence spectrum of tissue reflectivity. Effects of the ultrasound measurement system, echo signal windowing, electronic noise, and tissue motion on echo decorrelation images are determined theoretically, leading to a method for reduction of motion and noise artifacts. Theoretical analysis is validated by simulations and experiments. Simulated decoherence of the scattering medium was recovered with root-mean-square error less than 10% with accuracy dependent on the correlation window size. Motion-induced decorrelation measured in an ex vivo pubovisceral muscle model showed similar trends to theoretical motion-induced decorrelation for a 2.1 MHz curvilinear array with decorrelation approaching unity for 3-4 mm elevational displacement or 1-1.6 mm range displacement. For in vivo imaging of porcine liver by a 7 MHz linear array, theoretical decorrelation computed using image-based motion estimates correlated significantly with measured decorrelation (r = 0.931, N = 10). Echo decorrelation artifacts incurred during in vivo radiofrequency ablation in the same porcine liver were effectively compensated based on the theoretical echo decorrelation model and measured pre-treatment decorrelation. These results demonstrate the potential of echo decorrelation imaging for quantification of heat-induced changes to the scattering tissue medium during thermal ablation.
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Affiliation(s)
- Fong Ming Hooi
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45267-0586
| | - Anna Nagle
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45267-0586
| | - Swetha Subramanian
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45267-0586
| | - T Douglas Mast
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45267-0586
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Zhou Z, Wu W, Wu S, Xia J, Wang CY, Yang C, Lin CC, Tsui PH. A survey of ultrasound elastography approaches to percutaneous ablation monitoring. Proc Inst Mech Eng H 2014; 228:1069-82. [DOI: 10.1177/0954411914554438] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Percutaneous thermal ablation has been widely used as a minimally invasive treatment for tumors. Treatment monitoring is essential for preventing complications while ensuring treatment efficacy. Mechanical testing measurements on tissue reveal that tissue stiffness increases with temperature and ablation duration. Different types of imaging methods can be used to monitor ablation procedures, including temperature or thermal strain imaging, strain imaging, modulus imaging, and shear modulus imaging. Ultrasound elastography demonstrates the potential to become the primary imaging modality for monitoring percutaneous ablation. This review briefly presented the state-of-the-art ultrasound elastography approaches for monitoring radiofrequency ablation and microwave ablation. These techniques were divided into four groups: quasi-static elastography, acoustic radiation force elastography, sonoelastography, and applicator motion elastography. Their advantages and limitations were compared and discussed. Future developments were proposed with respect to heat-induced bubbles, tissue inhomogeneities, respiratory motion, three-dimensional monitoring, multi-parametric monitoring, real-time monitoring, experimental data center for percutaneous ablation, and microwave ablation monitoring.
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Affiliation(s)
- Zhuhuang Zhou
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Weiwei Wu
- College of Electronic Information and Control Engineering, Beijing University of Technology, Beijing, China
| | - Shuicai Wu
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Jingjing Xia
- School of Electronic Information Engineering, Tianjin University, Tianjin, China
| | - Chiao-Yin Wang
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chunlan Yang
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Chung-Chih Lin
- Department of Computer Science and Information Engineering, Chang Gung University, Taoyuan, Taiwan
| | - Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Medical Image Research Center, Institute for Radiological Research, Chang Gung University, Taoyuan, Taiwan
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33
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Hoerig CL, Serrone JC, Burgess MT, Zuccarello M, Mast TD. Prediction and suppression of HIFU-induced vessel rupture using passive cavitation detection in an ex vivo model. J Ther Ultrasound 2014; 2:14. [PMID: 25232483 PMCID: PMC4159109 DOI: 10.1186/2050-5736-2-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 07/15/2014] [Indexed: 12/28/2022] Open
Abstract
Background Occlusion of blood vessels using high-intensity focused ultrasound (HIFU) is a potential treatment for arteriovenous malformations and other neurovascular disorders. However, attempting HIFU-induced vessel occlusion can also cause vessel rupture, resulting in hemorrhage. Possible rupture mechanisms include mechanical effects of acoustic cavitation and heating of the vessel wall. Methods HIFU exposures were performed on 18 ex vivo porcine femoral arteries with simultaneous passive cavitation detection. Vessels were insonified by a 3.3-MHz focused source with spatial-peak, temporal-peak focal intensity of 15,690–24,430 W/cm2 (peak negative-pressure range 10.92–12.52 MPa) and a 50% duty cycle for durations up to 5 min. Time-dependent acoustic emissions were recorded by an unfocused passive cavitation detector and quantified within low-frequency (10–30 kHz), broadband (0.3–1.1 MHz), and subharmonic (1.65 MHz) bands. Vessel rupture was detected by inline metering of saline flow, recorded throughout each treatment. Recorded emissions were grouped into ‘pre-rupture’ (0–10 s prior to measured point of vessel rupture) and ‘intact-vessel’ (>10 s prior to measured point of vessel rupture) emissions. Receiver operating characteristic curve analysis was used to assess the ability of emissions within each frequency band to predict vessel rupture. Based on these measurements associating acoustic emissions with vessel rupture, a real-time feedback control module was implemented to monitor acoustic emissions during HIFU treatment and adjust the ultrasound intensity, with the goal of maximizing acoustic power delivered to the vessel while avoiding rupture. This feedback control approach was tested on 10 paired HIFU exposures of porcine femoral and subclavian arteries, in which the focal intensity was stepwise increased from 9,117 W/cm2 spatial-peak temporal-peak (SPTP) to a maximum of 21,980 W/cm2, with power modulated based on the measured subharmonic emission amplitude. Time to rupture was compared between these feedback-controlled trials and paired controller-inactive trials using a paired Wilcoxon signed-rank test. Results Subharmonic emissions were found to be the most predictive of vessel rupture (areas under the receiver operating characteristic curve (AUROC) = 0.757, p < 10-16) compared to low-frequency (AUROC = 0.657, p < 10-11) and broadband (AUROC = 0.729, p < 10-16) emissions. An independent-sample t test comparing pre-rupture to intact-vessel emissions revealed a statistically significant difference between the two groups for broadband and subharmonic emissions (p < 10-3), but not for low-frequency emissions (p = 0.058). In a one-sided paired Wilcoxon signed-rank test, activation of the control module was shown to increase the time to vessel rupture (T- = 8, p = 0.0244, N = 10). In one-sided paired t tests, activation of the control module was shown to cause no significant difference in time-averaged focal intensity (t = 0.362, p = 0.363, N = 10), but was shown to cause delivery of significantly greater total acoustic energy (t = 2.037, p = 0.0361, N = 10). Conclusions These results suggest that acoustic cavitation plays an important role in HIFU-induced vessel rupture. In HIFU treatments for vessel occlusion, passive monitoring of acoustic emissions may be useful in avoiding hemorrhage due to vessel rupture, as shown in the rupture suppression experiments.
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Affiliation(s)
| | | | - Mark T Burgess
- University of Cincinnati, Cincinnati, OH 45267-0586, USA
| | | | - T Douglas Mast
- University of Cincinnati, Cincinnati, OH 45267-0586, USA
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