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Digital Image Elasto Tomography (DIET) is a non-invasive elastographic breast cancer screening technology, based on image-based measurement of surface vibrations induced on a breast by mechanical actuation. Knowledge of frequency response characteristics of a breast prior to imaging is critical to maximize the imaging signal and diagnostic capability of the system. A feasibility analysis for a non-invasive...
This paper summarizes dynamic measurements of shear modulus constants acquired for spontaneously growing rat mammary tumors. Measurements are compared with histology to determine tumor types. We also report on 3D shear-wave velocity fields acquired from an inhomogeneous hydrogel phantom with known mechanical properties. Phantom measurements enable us to interpret the effects of tissue structure and...
A smart miniaturized system is being proposed for the isolation and characterization of circulating tumor cells (CTCs) directly from blood. Different microfluidic modules have been designed for cell enrichment and -counting, multiplex mRNA amplification as well as DNA detection. With the different modules at hand, future effort will focus on the integration of the modules in a fully automated, single...
A re-entrant resonant cavity applicator system for non-invasive brain tumor hyperthermia treatments was presented. We have already confirmed the effectiveness of the heating properties of this heating system with cylindrical agar phantoms and with computer simulations. This paper describes the specific absorption rate (SAR) analysis of this heating system for non-invasive brain tumor hyperthermia...
The aim of this paper is to present a new noninvasive method for investigating the homogeneity of the thyroid gland geometric model. The amplitude of reflected signal depends on the shape, size and homogeneity of the object investigated acoustic as well as the signal frequency emitted by generator. The eigenvalues proportional to the resonance frequencies are obtained by using finite element method...
This paper studies the decomposition of the time reversal operator (DORT, by the French acronym) technique for microwave breast lesion classification. We apply the finite-difference time-domain (FDTD) method to a realistic numerical breast phantom where lesion-like targets are artificially introduced, and obtain the multistatic data matrix (MDM) for a particular antenna array configuration. Then,...
The aim of this paper is to introduce effects well known to clinicians -but neglected to date- in the biomechanical modelling of breast malignant tumours. We develop a model of an isolated stellate breast tumour under mammographic compression forces. We study a range of reported mechanical properties, both linear elastic and hyperelastic. We also introduce different volumes of increased density/stiffness...
The correct needle placement is one of the crucial tasks in performing radiofrequency tumor ablation (RFA). In this work we evaluated the effects of imperfect needle placement for RFAs that are performed with an expandable needle array by using a finite-element simulation. We performed simulations for normal liver tissue with hypo- and hyperperfused metastasis as well as for cirrhotic liver tissue...
This paper reports a method that aims to quantify the changes of tumour vascular structure as a result of drug treatment. The measures we have investigated to date include: vessel radii, inter-branch lengths, tortuosity and branch angles. We show that the distribution of vessel radii is better modelled as a gamma distribution as opposed to the log-normal distribution asserted by other researchers...
Aggressive tumour types such as glioblastomas (gl) and metastases (me) are known to be difficult to discriminate on the basis of single-voxel proton magnetic resonance spectroscopy (SV 1H-MRS) information. Each of them is also heterogeneous in nature and a statistically robust subtyping analysis is likely to shed light on their structure and, possibly, on their differences. In this brief paper we...
Identification, analysis, and treatment of potential risk in surgical workflow are the key to decrease medical errors in operating room. For the automatic analysis of recorded surgical information, this study reports multichannel audio visual recording system, and its review and analysis system. Motion in operating room is quantified using video file size without motion tracking. Conversation among...
RF ablation (RFA) is used for thermal ablation of tumors in which the RF electrode is placed in the tissue under image-guidance. Because of the good tumor visibility and the lack of ionizing radiation, MR-guided RFA is the method of choice. Additionally, with the help of MR thermometry the RF ablation can be monitored during the intervention. Unfortunately, the imaging of an MR scanner is highly sensitive...
Radiofrequency (RF) ablation uses RF current to heat and kill cancer applied via an electrode inserted under image-guidance, and is in clinical use for tumors in liver, lung kidney, and bone. Mathematical models are frequently used to determine tissue temperature during RF ablation, but most prior models do not include accurate implementation of power control algorithms as are used in clinical devices...
In this paper we propose an application of local statistical models to the problem of identifying patients with pathologic complete response (PCR) to neoadjuvant chemotherapy. The idea of using local models is to split the input space (with data from PCR and NoPCR patients) and build a model for each partition. After the construction of the models we used bayesian classifiers and logistic regression...
In clinical routine of liver surgery there are a multitude of risks such as vessel injuries, blood loss, incomplete tumor resection, etc. In order to avoid these risks the surgeons perform a planning of a surgical intervention. A good graphical representation of the liver and its inner structures is of great importance for a good planning. In this work we introduce a new planning system for liver...
Magnetic Resonance Targeting (MRT) uses MRI for gathering tracking data to determine the position of microscale entities with the goal of guiding them towards a specific target in the body accessible through the vascular network. At full capabilities, a MRT platform designed to treat a human would consist of a clinical MRI scanner running special algorithms and upgraded to provide propulsion gradient...
Photodynamic therapy (PDT) is a potential cancer therapy used in several clinical fields. Its application in dermatology following a fixed protocol usually generates good results. However, some cases of basal cell carcinoma show tumour persistence. The poor response observed in this type of pathology, whose lesions penetrate in the deeper layers of the skin, could be attributed to an insufficient...
Irreversible electroporation (IRE) has shown promise for the therapeutic treatment of focal disease, including tumors. The effects of treatment are dependent on the electric field distribution, which may be predicted with numerical modeling. In order to improve the effectiveness and scope of IRE therapies, techniques must be developed for designing protocols capable of treating large and irregular...
Localized tumor hyperthermia therapy has been intensively studied for the past three decades. One engineering limitation has been the difficulty of specifically targeting cancerous tissues in the normal tissue surroundings. Recent attention has turned to the deposition of nanoparticles in the tumor to enhance heating relative to its surroundings. The work in magnetic nanoparticles has focused on resonant...
Bioluminescence of luciferase-expressing cells in live animals is a promising technique for image guided tumor resection. However, requiring exact optical tissue parameters is an underlying problem of diffusion equation when recovering bioluminescent images of luciferase activity within a volume using emission optical signal data from internal light sources. In this paper, an equivalence method based...
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