scholarly journals Monitoring Thermal Ablation via Microwave Tomography: An Ex Vivo Experimental Assessment

Diagnostics ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 81 ◽  
Author(s):  
Rosa Scapaticci ◽  
Vanni Lopresto ◽  
Rosanna Pinto ◽  
Marta Cavagnaro ◽  
Lorenzo Crocco
Keyword(s):  
Thermal Ablation ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Bovine Liver ◽  
Electromagnetic Properties ◽  
Microwave Tomography ◽  
Temperature Dependent ◽  
Discussion Section ◽  
Monitoring Technique ◽  
Significant Temperature

Thermal ablation treatments are gaining a lot of attention in the clinics thanks to their reduced invasiveness and their capability of treating non-surgical patients. The effectiveness of these treatments and their impact in the hospital’s routine would significantly increase if paired with a monitoring technique able to control the evolution of the treated area in real-time. This is particularly relevant in microwave thermal ablation, wherein the capability of treating larger tumors in a shorter time needs proper monitoring. Current diagnostic imaging techniques do not provide effective solutions to this issue for a number of reasons, including economical sustainability and safety. Hence, the development of alternative modalities is of interest. Microwave tomography, which aims at imaging the electromagnetic properties of a target under test, has been recently proposed for this scope, given the significant temperature-dependent changes of the dielectric properties of human tissues induced by thermal ablation. In this paper, the outcomes of the first ex vivo experimental study, performed to assess the expected potentialities of microwave tomography, are presented. The paper describes the validation study dealing with the imaging of the changes occurring in thermal ablation treatments. The experimental test was carried out on two ex vivo bovine liver samples and the reported results show the capability of microwave tomography of imaging the transition between ablated and untreated tissue. Moreover, the discussion section provides some guidelines to follow in order to improve the achievable performances.

Temperature-Dependent Thermal Properties of ex Vivo Liver Undergoing Thermal Ablation

2013 ◽  
Vol 39 (10) ◽  
pp. 1771-1784 ◽  
Author(s):  
Sitaramanjaneya Reddy Guntur ◽  
Kang Il Lee ◽  
Dong-Guk Paeng ◽  
Andrew John Coleman ◽  
Min Joo Choi
Keyword(s):  
Thermal Properties ◽  
Thermal Ablation ◽  
Ex Vivo ◽  
Temperature Dependent

scholarly journals Spatiotemporal Thermal Contours mapping of ex-vivo Bovine Liver Radiofrequency Thermal Ablation utilizing Hyperspectral Image and its Associated K-Mean Clustering Algorithm

2020 ◽  
Vol 1 (1) ◽  
pp. 01-13
Author(s):  
Mohamed Hisham Aref ◽  
Ibrahim H. Aboughaleb ◽  
Mohamed Rabie ◽  
Yasser H. El-Sharkawy
Keyword(s):  
Radiofrequency Ablation ◽  
Hyperspectral Imaging ◽  
Spectral Range ◽  
Thermal Ablation ◽  
Clustering Algorithm ◽  
Spatial Information ◽  
Ex Vivo ◽  
Bovine Liver ◽  
Detection Techniques ◽  
Risk Of Cancer

Significance: Hepatocellular carcinoma (HCC) is considered as worldwide health problem with a poor diagnosis due to limited detection techniques. Thermal ablation is the dominant modality to treat liver tumors for discriminating patients who are not allowed to have surgical intervention. Knowing that, observing or foreseeing the size of the subsequent tissue putrefaction during the Thermal Ablation techniques is a difficult undertaking. Aim: To examine the impacts of ablation zone volume following Radiofrequency ablation (RFA) of an ex-vivo bovine liver to correlate the impacts of thermal ablation with target organ perfusion; by exploiting the unique properties of Hyperspectral Imaging (HSI).where, Vessels may source cooling in the adjacent tumor target (heat‑sink‑effect) with risk of cancer recurrence and the infiltration profundity estimations consider the lessening of the tissue. Materials and Methods: Radiofrequency ablation was perfused on ex-vivo bovine livers at peripheral and central‑vessel‑adjacent locations, and monitored by HSI with a spectral range from 400 to 1000 nm. The system contains k-means clustering (K=8) algorithms combining spectral and spatial information. Labeled spectral signatures datasets were used as training data. Statistical analysis (10 samples) was computed to calculate the highest variance between six spectral images for determining the optimum wavelength for discrimination between the affected regions after thermal ablation (normal, thermal, and ablated liver tissue regions). Results: The change of the optical properties of ex-vivo liver tissues provides different responses to light transmission, scattering, absorption and particularly the reflection over the spectrum range. The spectral reflectance signatures were measured and evaluated using designed K-mean clustering algorithm after image reconstructed. Trials showed that spectral region 650~650 nm was proposed as optimum spectral range. Where, these results successfully distinguishes the Surface Thermal ablation region (x,y-axis),as well as the Thermal penetration Depth (z-axis) for Tissue characterization and Contour mapping for the unwanted thermal damage. Conclusions: Hyperspectral imaging is a powerful tool in real-time monitoring the thermal ablation and more accurate compared to the conventional imaging modality.

scholarly journals Exploiting Microwave Imaging Methods for Real-Time Monitoring of Thermal Ablation

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Rosa Scapaticci ◽  
Gennaro G. Bellizzi ◽  
Marta Cavagnaro ◽  
Vanni Lopresto ◽  
Lorenzo Crocco
Keyword(s):  
Real Time ◽  
Thermal Ablation ◽  
Ex Vivo ◽  
Local Heating ◽  
Biological Tissues ◽  
Microwave Imaging ◽  
Electromagnetic Properties ◽  
Potential Candidate ◽  
Real Time Monitoring ◽  
Concept Validation

Microwave thermal ablation is a cancer treatment that exploits local heating caused by a microwave electromagnetic field to induce coagulative necrosis of tumor cells. Recently, such a technique has significantly progressed in the clinical practice. However, its effectiveness would dramatically improve if paired with a noninvasive system for the real-time monitoring of the evolving dimension and shape of the thermally ablated area. In this respect, microwave imaging can be a potential candidate to monitor the overall treatment evolution in a noninvasive way, as it takes direct advantage from the dependence of the electromagnetic properties of biological tissues from temperature. This paper explores such a possibility by presenting a proof of concept validation based on accurate simulated imaging experiments, run with respect to a scenario that mimics an ex vivo experimental setup. In particular, two model-based inversion algorithms are exploited to tackle the imaging task. These methods provide independent results in real-time and their integration improves the quality of the overall tracking of the variations occurring in the target and surrounding regions.

scholarly journals Frequency and average gray-level information for thermal ablation status in ultrasound B-Mode sequences

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jens Ziegle ◽  
Alfredo Illanes ◽  
Axel Boese ◽  
Michael Friebe
Keyword(s):  
Thermal Ablation ◽  
Ex Vivo ◽  
Cell Damage ◽  
Potential Temperature ◽  
Image Sequences ◽  
Target Tissue ◽  
Gray Level ◽  
Porcine Liver ◽  
Time Frequency ◽  
Average Gray Level

AbstractDuring thermal ablation in a target tissue the information about temperature is crucial for decision making of successful therapy. An observable temporal and spatial temperature propagation would give a visual feedback of irreversible cell damage of the target tissue. Potential temperature features in ultrasound (US) B-Mode image sequences during radiofrequency (RF) ablation in ex-vivo porcine liver were found and analysed. These features could help to detect the transition between reversible and irreversible damage of the ablated target tissue. Experimental RF ablations of ex-vivo porcine liver were imaged with US B-Mode imaging and image sequences were recorded. Temperature was simultaneously measured within the liver tissue around a bipolar RF needle electrode. In the B-Mode images, regions of interest (ROIs) around the centre of the measurement spots were analysed in post-processing using average gray-level (AVGL) compared against temperature. The pole of maximum energy level in the time-frequency domain of the AVGL changes was investigated in relation to the measured temperatures. Frequency shifts of the pole were observed which could be related to transitions between the states of tissue damage.

Hyperspectral image-based analysis of thermal damage for ex-vivo bovine liver utilizing radiofrequency ablation

2021 ◽  
pp. 101564
Author(s):  
Mohamed Hisham Aref ◽  
Ibrahim H. Aboughaleb ◽  
Abou-Bakr M. Youssef ◽  
Yasser H. El-Sharkawy
Keyword(s):  
Radiofrequency Ablation ◽  
Thermal Damage ◽  
Hyperspectral Image ◽  
Ex Vivo ◽  
Bovine Liver

Increased Ablation Zones Using a Cryo-Based Internally Cooled Bipolar RF Applicator in Ex Vivo Bovine Liver

2009 ◽  
Vol 44 (12) ◽  
pp. 763-768 ◽  
Author(s):  
Hansjörg Rempp ◽  
Matthias Voigtländer ◽  
Stephan Clasen ◽  
Simone Kempf ◽  
Alexander Neugebauer ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Bovine Liver ◽  
Internally Cooled
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