19 documents found, page 1 of 2
In Vivo Measurements of Murine Melanoma's Complex Permittivity Between 500 MHz ...
Pelicano, Ana Catarina; Gaspar, Maria Manuela; Reis, Catarina P.; Araújo, Nuno A. M.; Conceição, Raquel C.; Godinho, Daniela M.Complex permittivity measurements of murine melanoma tumours were performed via open-ended coaxial probe technique for frequencies ranging from 500 MHz to 8.5 GHz. The measurements were conducted in five mice containing a melanoma tumour each, while the animals were under anaesthesia. Two different measurement methodologies were employed. Eighty-six in vivo measurements of melanoma’s permittivity were collected...
Best Practices for Accurate Results Using Numerical Solvers for Microwave Body ...
Martins, Raquel A.; Godinho, Daniela M.; Felício, João M.; Savazzi, Matteo; Costa, Jorge R.; Conceição, Raquel C.; Fernandes, Carlos A.In this paper, we indicate best practices that should be observed when using numerical solvers for microwave body sensing. We show the impact of not minding these aspects in the case of microwave breast scanning, using the Computer Simulation Technology software tool. To this end we simulate a homogeneous breast with a 5-mm radius spherical tumor placed inside. The breast is illuminated by a broadband antenna t...
Studying the Effects of Water Content in Breast Microwave Imaging with a Volunteer
Godinho, Daniela M.; Simões, Afonso; Mendes, Bruno; Canastra, Gonçalo; Correia, Inês A.; Saraiva, Joana; Dias, Rodrigo; Conceição, Raquel C.Microwave Imaging (MWI) has been studied for early breast cancer detection in the last few decades. Volunteer and patient studies have recently been performed in academia and industrial environments [1]. Nevertheless, the axillary region, which may be affected by breast cancer, has not been assessed in such studies.
The Effect of Pressure of the Open-ended Coaxial Probe on the Measurement of Ex...
Pelicano, Ana Catarina; Araújo, Nuno A. M.; Godinho, Daniela M.; Conceição, Raquel C.The impact of increasing evenly spaced pressures, between 2.58 and 25.8 kPa, on dielectric data ranging from 0.5 to 8.5 GHz was studied using 1×1×1 cm3 and 2×2×2 cm3 of bovine liver and chicken muscle samples. Results show a reduction exceeding 15% in tissue dielectric properties as pressure increased, until a breaking point is reached, and the trend reversed. The initial decline of dielectric properties aligns...
Initial Study of Detection and Repeatability of Microwave Imaging with Monopole...
Correia, Inês; Godinho, Daniela M.We are building a new Microwave Imaging (MWI) prototype to image both the breast and the axillary region, to be used as a potential complementary method for breast cancer diagnosis. In this work, we evaluated our antennas performance with simplified breast phantoms, while testing the effect of plastic in phantoms on imaging results and the repeatability of our system. Results suggest plastic has no significant ...
Study of Best Antenna Configuration for Axillary Microwave Imaging Prototype
Godinho, Daniela M.; Conceição, Raquel C.Imaging the axillary region for detection of axillary lymph nodes metastasised by breast cancer is currently under development using microwave signals. A limited angular view justifies the study of the best antenna configuration for this application. In this paper, we perform a preliminary study to find the best antenna configurations for axillary microwave imaging. The results show the quality of target detect...
Repository of MRI-derived models of the breast with single and multiple benign ...
Pelicano, Ana C.; Gonçalves, Maria C. T.; Castela, Tiago; Orvalho, M. Lurdes; Araújo, Nuno A. M.; Porter, Emily; Conceição, Raquel C.The diagnosis of breast cancer through MicroWave Imaging (MWI) technology has been extensively researched over the past few decades. However, continuous improvements to systems are needed to achieve clinical viability. To this end, the numerical models employed in simulation studies need to be diversified, anatomically accurate, and also representative of the cases in clinical settings. Hence, we have created t...
Breast MRI Multi-Tumor Segmentation using 3D Region Growing
Pelicano, Ana Catarina; Godinho, Daniela M.; Gonçalves, Maria C. T.; Castela, Tiago; Orvalho, Maria Lurdes; Sencadas, Vitor; Sebastião, RaquelBreast tumor is one of the most prominent indicators for diagnosis of breast cancer. Magnetic Resonance Imaging (MRI) is a relevant imaging modality tool for breast cancer screening. Moreover, an accurate 3D segmentation of breast tumors from MRI scans plays a key role in the analysis of the disease. This paper presents a pipeline to automatically segment multiple tumors in breast MRI scans, following the metho...
Validation of Dielectric Properties Estimation from Magnetic Resonance Images t...
Godinho, Daniela M.; Castela, Tiago; Felício, João M.; Silva, Nuno A.; Orvalho, M. Lurdes; Fernandes, Carlos A.; Conceição, Raquel C.Knowledge about dielectric properties of biological tissues is critical for the development and validation of microwave systems, such as Microwave Imaging (MWI) prototypes. However, measurement of dielectric properties of heterogeneous tissues with conventional techniques present some challenges, as most adopted techniques are designed for homogeneous tissues, and limited number of samples may be available. In ...
Experimental Evaluation of an Axillary Microwave Imaging System to Aid Breast C...
Godinho, Daniela M.; Felicio, Joao M.; Fernandes, Carlos A.; Conceicao, Raquel C.The number of metastasised Axillary Lymph Nodes (ALNs) is a key indicator for breast cancer staging. Its correct assessment affects subsequent therapeutic decisions. Common ALN screening modalities lack high enough sensitivity and specificity. Level I ALNs produce detectable backscattering of microwaves, opening the way for Microwave Imaging (MWI) as a complementary screening modality. Radar-based MWI is a low-...