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This paper aims to apply a proposed, based on calorimetric measurements, a reliable numerical model for magnetic fluid hyperthermia (MFH) treatment planning of breast cancer. Furthermore, we perform a comparative analysis of magnetic nanoparticles (MNPs) and tumour tissue interactions by means of the magnetic-field-dependent N&eacute, el and Brownian relaxation times. The analysis was based on an anatomically correct breast model (developed in-house) and a modified linear response theory, which was applied to investigate the heat dissipation from the magnetic nanoparticles dispersed in the breast tumour. The calculations of the single-domain magnetic power losses were conducted for a case where the magnetic field value and the applied frequency were known, but also for the different concentrations of the MNPs in the tumour. Two scenarios were considered: The MNPs mobilised and immobilised in the tumour. In parallel, the eddy currents effect, together with the related temperature distributions, were considered in order to analyse safety issues. By changing the MNP concentration in the tumour, the corresponding temperature distributions were calculated. The eddy current effect, together with the related temperature distribution, were considered in order to analyse safety issues. Varying the MNP concentration in the tumour, the corresponding temperature distribution was calculated. Moreover, the cumulative equivalent minutes at 43 &nbsp, ℃ were analysed. In the anatomically correct breast phantoms, the tissue location can lead to &ldquo, hot spots&rdquo, due to the eddy current effect and subsequently to the high gradients of the temperature. That is why the analysis of safety issues related to the overheating side effect should be taken into consideration during the treatment planning of magnetic fluid hyperthermia. The phenomenon of heat dissipation from MNPs is very sophisticated and depends on their concentration, the distribution and the relaxation mechanism in the tumour, together with magnetic field strength and frequency. Furthermore, we inferred that the phenomenon of heat dissipation from MNPs equally depends on MNP-tissue interactions, and it can lead to 30% differences in the power assessment. Nevertheless, the aforementioned factors should be considered in parallel using anatomical, volume-dependent models to enhance the efficiency of in vivo treatment.

Background: The computer-aided diagnosis (CAD) has been applied in multiple studies conducted recently in order to perform ultrasound (US) of the breast. There are several studies that have indicated that CAD is useful for improving the diagnostic performance in less experienced radiologists. However, there is no study on several readers analyzing the same lesions using a breast phantom and rare reliability studies. Objectives: To investigate the reliability of different readers using computer aided diagnosis (CAD) system in US for determining identical lesions in a breast phantom. Patients and Methods: From March 2016 to February 2017, six readers (three senior and three junior residents in the department of radiology) evaluated and analyzed breast phantom including 14 lesions. At the first line study, three senior residents (3rd grade with more than one month of training for breast ultrasound [US]) and three junior residents (1st grade without breast US training) evaluated and analyzed the US and applied CAD for lesions in breast phantom, and they were able to make final decisions by subjective combination. A month later, they conducted the second line study as they did the first line study. We analyzed the inter- and intra-reader reliability and accuracy of US, CAD, and combinations (subjective, conjunctive, and disjunctive). Results: In the total of first and second line studies of six readers, the kappa value of US (0.609) was significantly higher than CAD (0.411). In the subjective combined conclusion, the kappa value was improved by the junior group. In the whole inter- and intra-reader analysis, the kappa values of final assessment of the senior and junior group were more variable on CAD than on US, especially in the junior group, and this result was statistically significant. The area under the curve (AUC) of US, CAD, subjective, conjunctive, and disjunctive combination in seniors were all better than those of juniors. In all groups, the AUCs, sensitivities, and specificities were improved on conjunctive combined US with CAD. Conclusion: The combination US with CAD improved the reliability and diagnostic performance. The CAD results of the junior group were variable and inconsistent. Therefore, minimum training and experience for breast US is indispensable for the better use of breast CAD, and, combination US with CAD is useful for all readers.

This paper introduces a novel design of circular antenna array in ring configuration which operated at frequency 3.4 GHz – 7.4 GHz. The antenna is designed and simulated to detect the presence of a tumor. The analysis is done by comparing the E-field, H-field, and Specific Absorption Rate (SAR) to the breast with tumor (r=4mm). With ring configuration, each element of the antenna is directly faced to the breast phantom for better tumor detection. The simulated E-field of 10311 V/m and H-field of 78.7 A/m are obtained for the breast with the tumor. The simulated SAR of 1.32 W/Kg is resulted and safe to use.

UWB microwave imaging has been demonstrated to have clinical potentials for breast screening. However, existing imaging system either incorporate commercial VNA or simplify the system by sacrificing bandwidth or ADC accuracy. We proposed a system that equips a rotation mechanism to reduce antenna elements and a line laser for skin surface estimation. We demonstrated the feasibility of the system through silica gel based breast phantom.

International audience; Millimeter (mm)-wave imaging has been recently proposed as a new technique for breast cancer detection, based on the significant dielectric contrast between healthy and tumor tissues. Here we propose a procedure to fabricate, electromagnetically characterize and preserve realistic breast tissue-mimicking phantoms for testing mm-wave imaging prototypes. Low-cost, non-toxic and easy-to-produce mixtures made of sunflower oil, water and gelatin were prepared and their dielectric properties were for the first time measured in the [0.5-50] GHz frequency range using a coaxial probe kit. Different oil and gelatin percentages were tested. An alternative recipe based on a waste-oil hardener was also proposed. Finally, water and sunflower oil were investigated as preservation media. The mixtures electromagnetic properties were in good agreement with those of human breast ex vivo samples. By changing the ingredient concentrations or using different solidifying agents it was possible to mimic different tissue types. Besides, we show that sunflower oil represents an effective preservation medium for the developed materials. The first breast phantom mimicking a tumor mass into healthy tissues up to 50 GHz was also successfully fabricated. Results demonstrated the potential of the designed recipes to mimic breast tissues with different biological characteristics, 2 preserving dielectric properties over time. Thus, this study represents a fundamental step towards the development of heterogeneous breast phantoms able to mimic the electromagnetic behavior of healthy and tumor tissues for mm-wave imaging applications.

The purpose of this study was to evaluate the feasibility of spectral mammography using the dual-energy method to noninvasively distinguish between type I (calcium oxalate, CO) and type II (calcium hydroxyapatite, HA) microcalcifications. Two types of microcalcifications are difficult to distinguish due to a similar linear attenuation coefficient. In order to improve the detection efficiency of microcalcifications, we used the photon counting detector with energy discrimination capability and microcalcifications were classified into optimal energy bins. Two energy bins were used to obtain dualenergy images. In this study, photon counting spectral mammography system was simulated using Geant4 Application for Tomographic Emission (GATE) simulation tools. The thickness of the breast phantom was 3 cm and microcalcifications of various sizes ranging from 130-550 μm were embedded into the breast phantom. Microcalcifications were classified as being calcium hydroxyapatite or calcium oxalate based on score calculation with the dual-energy images. According to the results, the measured CNR of calcium hydroxyapatite (HA) was higher than that of the calcium oxalate (CO) in conventional single-energy image. In addition, two types of microcalcifications were distinguished using dual-energy analysis method. This classification represents better performance with a high energy of 50 kVp and an energy threshold of 30 keV. These results indicate that the classification performance was improved when the difference in the low energy image and high energy image was used. This study demonstrated the feasibility of photon counting spectral mammography for classification of breast microcalcifications. We expect that dual-energy method can reduce the frequency of biopsy and discriminate microcalcifications in mammography. These results are expected to potentially improve the efficiency of early breast cancer diagnosis.

In this paper, the performances of two time-reversal (TR) based algorithms namely time-reversal multiple signal classification (TR-MUSIC) and decomposition of time reversal operator (DORT under its French acronym) for detecting breast cancer through UWB microwave imaging, are assessed. These assessments are carried out by changing the location of a hypothetical spherical tumor in an MRI-based numerical breast phantom through simulations in CST microwave studio environment. The recorded data is processed by the two TR-based procedures which result in the final images of cancerous breast tissues. In all cases, data acquisition has been conducted in 2 steps with and without a tumor inside the breast. During each step, UWB pulses within the wideband frequency range of 2-5 GHz are transmitted by 16-element antenna array which also receives backscattered signals from the breast tissue. In this work, we show that the implemented method can locate tumors with high precision, whether the tumor is located in the middle of the breast phantom, near to the skin or even close to the muscle wall which possesses a high reflectivity.

International audience; Mammography is the first tool in breast cancer diagnosis. Its contrast relies on the difference of X-Ray attenuation in healthy and diseased tissues, which is quite limited. This leads to frequent false-positive or inconclusive results and requires further testing. X-Ray Diffraction provides information about molecular structure and can differentiate between healthy and cancerous breast tissues. It can thus be used in synergy with existing imaging methods to provide complementary diagnosis-relevant insight.We present a novel geometry of such an imaging system and its validation on a breast phantom composed ofolive oil and beef muscle, imitating respectively the molecular structure of healthy and cancerous breast tissue.Our system combines energy-dispersive and angle-dispersive X-Ray diffraction by means of an energy-resolvedCdZnTe detector and a multi-slit collimation in order to achieve depth-resolved imaging.The position of the tube with beef muscle inside the oil was varied in this experiment. The obtained results aresatisfactory regarding the estimated position of the tube which is very promising for future ex-vivo experiments on human breast tissue samples. Further investigations are carried out on dose reduction and reliable classification algorithms in order to prepare this method for clinical applications.

Photoacoustic tomographic breast imaging systems progressively move into the clinics for in-vivo studies. Next to tumor detection, studies also focus on extracting information about the tumor by performing multi-wavelength photoacoustics for quantitative oxygen saturation estimations. Until now, it has been difficult to compare the results from different systems due to the wide variability in system characteristics and image reconstruction algorithms. In order to do inter-system comparisons in photoacoustic breast imaging, and to validate oxygen saturation estimations, a standardized but realistic measurement object is required. In this study, we present the first 3D semi-anthropomorphic photoacoustic breast phantom and demonstrate its features both in ultrasound imaging as in photoacoustic tomography.

3D breast modelling for 2D and 3D breast x-ray imaging would benefit from the availability of digital and physical phantoms that reproduce accurately the complexity of the breast anatomy. While a number of groups have produced digital phantoms with increasing level of complexity, physical phantoms reproducing that software approach have been scarcely developed. One possibility is offered by 3D printing technology. This implies the assessment of the energy dependent absorption index β of 3D printing materials for absorption based imaging, as well as the assessment of the refractive index decrement, δ, of the printing material, for phase contrast imaging studies, at the energies of interest for breast imaging. In this work we set-up a procedure and performed a series of measurements (at 30, 45 and 60 keV, at the European Synchrotron Radiation Facility) for assessing the relative value of δ with respect to that of breast tissues, for twelve 3D printing materials. The method included propagation based phase contrast 2D imaging and retrieval of the estimated phase shift map, using the Paganin's algorithm. Breast glandular, adipose and skin tissues were used as reference materials of known ratio δ/β. A percentage difference Δδ was introduced to assess the suitability of the printing materials as tissue substitutes. The accuracy of the method (about 4%) was assessed based on the properties of PMMA and Nylon, acting as gold standard. Results show that, for the above photon energies, ABS is a good substitute for adipose tissue, Hybrid as a substitute of the glandular tissue and PET-G for simulating the skin. We plan to realize a breast phantom manufactured by fused deposition modelling (FDM) technology using ABS, Hybrid and PET-G as substitutes of the glandular and skin tissue and a second phantom by stereolithography (SLA) technology with the resins Flex, Tough and Black.

International audience; Realistic breast phantoms are often required for supporting the development of microwave and mm-wave imaging systems for breast cancer detection. A number of phantoms have been proposed in the literature, but they are often realized using non-common or toxic materials, and characterized only for the microwave regime. Recently, mm-waves have been also proposed for screening purposes, especially for breast with a high fat content, to provide the resolution vital to detect early-stage cancer masses. Consequently, we proposed several recipes that can be used to create tissue-mimicking materials able to reflect the dielectric properties of different human breast tissues, from fat to neoplastic tissues. In this paper, we present new recipes specifically conceived to mimic up to 50 GHz the dielectric properties of very fat tissues, difficult to achieve otherwise. The involved materials are deionized water, sunflower oil, waste-oil hardener, and two different surfactants (lecithin and Polysorbate 80), all very cheap, easy-to-manage, not-toxic and common materials.

Breast cancer diagnosis has been mostly accomplished by imaging technologies. These methods have the great advantages of detecting the presence and location of breast cancer. However, it's difficult to distinguish between a benign and malignant tumor in a deep position because both tumor types look similar. In this paper, we vibrated the tissue including tumor from skin with a compression cylinder to analyze the frequency difference for distinguishing the tissue type. Before distinguishing a benign and malignant tumor, it's necessary to validate to distinguish between normal tissue and tumor. The objective is to validate the feasibility of using a compression cylinder that emphasizes the differences in frequency between normal tissue and tumor. In two experiments, we measured the displacement on the surface of a breast phantom vibrated by an impulse hammer. We compared the frequency difference with and without a cylinder. We also studied the frequency changes in the relationship between tumor and cylinder position. We found a 5.0 Hz difference in compliance between normal tissue and the simulated tumor using a compression cylinder. The difference in frequency correlated negatively with distance from the simulated tumor to a compression cylinder. We concluded that a compression cylinder would enhance the frequency difference between normal tissue and a simulated tumor with appropriate configuration.

In this work we extend the functionality of the Direct Image Reconstruction for TOF (DIRECT) method to accommodate for spatially-variant image-based resolution modeling (IRM) of point-spread-function (PSF) deformations within reconstruction (varRM). The method is applied to simulation data for a dual-panel breast PET (B-PET) scanner geometry using a realistic breast model with heterogeneous breast density and lesions. Performance of the proposed method is evaluated by comparing contrast recovery coefficients (CRC) across lesions with those obtained with reconstruction of the breast phantom without IRM (NO_rm) and with a spatially-invariant IRM (invRM). It is shown that our reconstruction method (i.e., varRM) delivers lower variation (i.e., %SD) of CRC across lesions with an improvement in mean CRC when compared to both the NO_rm and invRM cases. In addition to recovering the original position of the simulated lesions.

Purpose We present a breast phantom designed to enable quantitative assessment of measurements of T1 relaxation time, apparent diffusion coefficient (ADC), and other attributes of breast tissue, with long-term support from a national metrology institute. Materials and Methods A breast phantom was created with two independent, interchangeable units for diffusion and T1/T2 relaxation, each with flexible outer shells. The T1 unit was filled with corn syrup solution and grapeseed oil to mimic the relaxation behavior of fibroglandular and fatty tissues, respectively. The diffusion unit contains plastic tubes filled with aqueous solutions of polyvinylpyrrolidone (PVP) to modulate the ADC. The phantom was imaged at 1.5T and 3.0T using magnetic resonance imaging (MRI) scanners and common breast coils from multiple manufacturers to assess T1 and T2 relaxation time and ADC values. Results The fibroglandular mimic exhibited target T1 values on 1.5T and 3.0T clinical systems (25–75 percentile range: 1289 to 1400 msec and 1533 to 1845 msec, respectively) across all bore temperatures. PVP solutions mimicked the range of ADC values from malignant tumors to normal breast tissue (40% PVP median: 633 × 10−6 mm2/s to 0% PVP median: 2231 × 10−6 mm2/s) at temperatures of 17–24°C. The interchangeable phantom units allowed both the diffusion and T1/T2 units to be tested on the left and right sides of the coil to assess any variation. Conclusion This phantom enables T1 and ADC measurements, fits in a variety of clinical breast coils, and can serve as a quality control tool to facilitate the standardization of quantitative measurements for breast MRI. J. Magn. Reson. Imaging 2016.

Aim To determine the most robust commonly available magnetic resonance imaging (MRI) sequence to quantify breast tissue composition at 1.5 T. Materials and methods Two-dimensional (2D) T1-weighted, Dixon fat, Dixon water and SPAIR images were obtained from five participants and a breast phantom using a 1.5 T Siemens Aera MRI system. Manual segmentation of the breasts was performed, and an in-house computer program was used to generate signal intensity histograms. Relative trough depth and relative peak separation were used to determine the robustness of the images for quantifying the two breast tissues. Total breast volumes and percentage breast densities calculated using the four sequences were compared. Results Dixon fat histograms had consistently low relative trough depth and relative peak separation compared to those obtained using other sequences. There was no significant difference in total breast volumes and percentage breast densities of the participants or breast phantom using Dixon fat and 2D T1-weighted histograms. Dixon water and SPAIR histograms were not suitable for quantifying breast tissue composition. Conclusion Dixon fat images are the most robust for the quantification of breast tissue composition using a signal intensity histogram. Refereed/Peer-reviewed

This paper deals with low cost and non-invasive wideband holographic microwave imaging system that operates in 5.05GHz-8.23GHz band. Emphasis is given here to detect tumor in 2D breast phantom using 18 bowtie antennas with 4 antennas serving as transmitters (Tx) and 14 antennas as receivers (Rx). Holographic microwave simulations have been done using MATLAB to detect the existence of tumor and its size. Results are shown for 2D reconstructed sliced images of the breast taken for four different transmitters. Holographic simulations demonstrate that array proposed in this paper has the ability to detect tumor of a size as small as 1.5 mm located at (x, y, z) = (0, 40, 30) within the breast tissues.

Because breast phantoms are central for evaluating 2D and 3D breast imaging systems, it is important to develop anthropomorphic, realistic phantoms that can be used in task-based assessment. The current phantoms available for use with full field digital mammography (FFDM) and digital breast tomosynthesis (DBT) are uniform or have otherwise unrealistic background texture. However, this work presents a task-based methodology for evaluating FFDM and DBT systems using two components: an anthropomorphic breast phantom created through inkjet printing and realistic pathological inserts with two types of microcalcifications (MCs). To create the phantom, a virtual breast was first modeled, then digitally compressed to a 4 cm thickness. To realize the phantom, virtual model was printed with an inkjet printer in a slice-by-slice fashion using iohexol-doped ink. The MC inserts were created using two types of materials. One set of MCs were made using calcium hydroxyapatite (HA) powder, and the other was made from sodalime coated glass (SLG) microspheres. The composite phantom plus two types of inserts was imaged on two commercially available FFDM/DBT systems: the GE Senographe Essential and the Hologic Selenia Dimensions. For the acquisitions, the automatic exposure control was used to determine a typical mammographic beam based on the phantom thickness. In addition, a similar a similar average glandular dose was used for both systems. A four alternative forced choice (4AFC) study was conducted to demonstrate the utility of the methodology and to evaluate the systems. Results of the 4AFC study showed higher detection of calcs for DBT versus FFDM on the GE system, but the reverse on the Hologic system. In this work, a breast phantom as created from inexpensive and easily accessible materials. This methodology is promising for the objective evaluation of task performance for 2D and 3D breast imaging systems.

Breast cancer is a major threatening disease to women’s life nowadays. To ensure a surviving chance for the patients, it is quite crucial to detect and treat the breast cancer in the early stage. This article deals with the detection of breast cancer using two different microwave imaging methods. The first method is based on synthetic aperture radar (SAR) qualitative imaging method, and the second is based on inverse scattering quantitative imaging method, which can also reconstruct the relative permittivity for the breast. A two-dimensional simplified breast phantom is used to test both algorithms and the imaging results show that both methods are able to detect the cancer cell with good resolution.

We present preliminary data for a novel platform that integrates focused microwave therapy (FMT) with thermoacoustic imaging (TAI) for mapping temperature, quantifying the heat zone, and guiding the delivery of focused heat. The longterm objectives of this study are to 1) Design and build an image-guided FMT system that is noninvasive, safe and effective for treating small or large locally aggressive solid breast tumors as a possible replacement or complement to invasive surgery; 2) Benchmark performance and optimize TAI-guided FMT platform using in numerical breast phantom and excised tissue. We present the overall system concept, numerical simulations and initial bench-top results related to the proposed platform.

The current contribution presents an approach for creation of complex computational breast phantoms, with included breast abnormalities. In-house developed and validated software tool, called BreastSimulator, is used to create different models of healthy breasts, by varying parameters like shape, size, duct tree features, Cooper ligaments, skin, etc. Separately, different 3D tumour models are constructed from segmented tumour regions on sets of real tomosynthesis images from real patients. A semi-automatic algorithm was developed to segment the abnormalities in the images. The algorithm applies a series of image processing operations and region-growing techniques with minimal interaction from the user to find the areas of the lesions. The flat tumour images are then correctly stacked and stored in a 3D voxel matrix, matching the desired resolution. Relevant information about the lesion (voxel size, matrix size, geometrical centre, etc.) is also saved. Selected tumour models are then inserted at various locations into the computational models of the healthy breasts. Examples of simulated mammographic and tomosynthesis images from such breast phantoms are presented to illustrate the potential of the proposed approach. Combining mathematical breast modelling with segmented real 3D tumour shapes results in the creation of realistic breast phantoms. The approach allows implementation of multiple scenarios and unlimited number of cases, which can be used for further software modelling and investigation of breast imaging techniques.

Purpose: To investigate the potential of spectral mammography to distinguish between type I microcalcifications, consisting of calcium oxalate dihydrate compounds typically associated with benign lesions, and type II microcalcifications containing hydroxyapatite which are predominantly detected in malignant tumors. Methods: Simulation and phantom studies were carried out using polyenergetic spectra from a tungsten anode x-ray tube at low and high voltage (kVp) settings. Low- and high-energy attenuation ratios were calculated for microcalcifications of different types and thicknesses. Classification of type I or II calcifications was performed by using the attenuation ratio as a criterion. The results were evaluated using receiver operating characteristic (ROC) analysis. Results: In simulation studies, four combinations of dual (low and high kVp) energy exposure technique were investigated: 1) 30 kVp, 1 mm aluminum filtration and 50 kVp, 0.1 mm copper filtration; 2) 30 kVp, 1 mm Al and 50 kVp 0.2 mm Cu; 3) 30 kVp, 2 mm Al and 50 kVp, 0.1 mm Cu; and 4) 30 kVp 2 mm Al and 50 kVp, 0.2 mm Cu. In the ROC curve analysis, area under the curve (AUC) values were above 0.95 for all of the spectra with the exposure equivalent to 1.5 mGy of the mean glandular dose delivered to a 4 cm thick breast phantom. 30 kVp/2 mm Al and 50 kVp/0.1 mm Cu tube voltage/filter combinations demonstrated better performance compared to other combinations. In phantom studies, a 40 kVp setting paired with 1 mm Al filter and a 70 kVp setting paired with 0.1 mm Cu filter operated at 20 mAs technique were used. Obtained AUC value was also high (0.91), supporting the accuracy of the proposed classification method. Conclusion: The results of the current study suggest that dual energy mammography systems have potential to be used for discrimination between type I and type II microcalcifications to improve early breast cancer diagnosis and reduce the number of unnecessary breast biopsies.

The breast phantoms currently available for evaluating full field digital mammography (FFDM), digital breast tomosynthesis (DBT), and breast CT (bCT) systems often lack the complexity present in real breasts. In this work we present a new methodology for creating physical anthropomorphic breast phantoms for use in FFDM, DBT, and dedicated bCT systems using zinc acetate-doped ink. First, an uncompressed virtual phantom was created through analytical modeling. The model represented a breast with 28% fibroglandular density with 13 tissue classes and contained a 5 mm lesion. The breast was binarized to two tissue classes: adipose and fibroglandular tissue. The phantom was then realized through inkjet printing using dye ink doped with zinc acetate for the fibroglandular components and three candidate materials for the adipose background: parchment paper, organic paper, and office paper. The fabrication process was evaluated in terms of material realism and reproducibility using spectroscopy, a clinical FFDM system, and a benchtop bCT system. The linear attenuation coefficient of the doped ink plus parchment paper and parchment paper alone closely matched those of the fibroglandular and adipose tissues, respectively. A methodology for generating anthropomorphic breast phantoms was developed using a novel inkjet printing technique for use in FFDM/DBT, as well as dedicated breast CT systems. A novel uncompressed breast phantom for bCT was fabricated using inexpensive, easily available materials with realistic tissue properties.

The aim was to measure the threshold diameter for detection of masses and calcifications in synthetic 2D images created from planes of digital breast tomosynthesis (DBT) of a mathematical breast phantom. The results were compared to those for 2D images and DBT. Simulated ill-defined masses and calcification clusters were inserted into mathematical breast models with a thickness of 53mm. The images were simulated as if acquired on a Siemens Inspiration X-ray system. Acquisitions of 2D and DBT images of the breast phantom at a mean glandular dose (MGD) of 1.6mGy were simulated using ray tracing with allowance for unsharpness and the addition of scatter and noise. The resultant images were processed using the manufacturer’s software to create 2D, DBT planes and synthetic 2D images. Image patches with or without the lesion were extracted. These patches were used in a 4-alternative forced choice study using 5 observers to measure the threshold diameter for each imaging mode. The threshold diameters of the masses and microcalcifications were 7.0mm, 6.3mm, 7.1mm and 4.9mm (masses) and 395μm, 211μm, 220μm, and 357μm (calcifications) for synthetic 2D, 2D (1.6mGy), 2D (1.1mGy) and DBT respectively. The threshold diameters were 10% (p=0.4) and 47% (p

A novel real-time monitoring method is presented based on thermoacoustic imaging for applications in breast cancer hyperthermia. In the proposed technique, thermoacoustic imaging combined with compressive sensing is implemented to improve monitoring efficiency. Numerical modeling work is done using a breast phantom, which has realistic dielectric properties and internal structures, to validate feasibility of the presented technique. Results of the modeling work clearly show the effectiveness of the monitoring method. This technique can also find applications in other types of hyperthermia.

This work presents an electromagnetic test of the breast for biomedical applications. The test is given in the Industrial Scientific Medical (ISM) band where the frequency equal to 2.4 GHz. The simulation results of the electromagnetic aspects of the proposed test are given by Computer Simulation Technology Microwave Studio (CST-MWS) based on finite integration technique (FIT) method. The treated parameter for the immunity test of the breast is the Specific Absorption Rate (SAR). We propose four models of the breast phantom to obtain a comparative study in terms of the size effect and the thickness of different layers. The simulation results show that the immunity of the breast is depends to the Power energy and the breast size.

Purpose: Contrast-enhanced spectral mammography (CESM) is diagnostically superior to full-field digital mammography. An important improvement for CESM would be the ability to quantify enhancement. In this proof-of-concept study we present a method for quantifying CESM enhancement.Methods and materials: We developed a custom-made quantifier tool (I-STRIP) containing five chambers, each filled with a different iodine mass thickness (IMT). CESM grey values of the recombined image (CGV) in the I-STRIP were used to quantify breast IMT. We evaluated the I-STRIP's accuracy using a dedicated breast phantom containing chambers with known IMT's. Furthermore, we tested the effect of the I-STRIP on image quality and clinical use in five patients. Retrospectively, we studied whether current CESM protocols could distinguish between malignant and benign lesions in terms of CGV.Results: Phantom experiments showed that quantification was independent of chamber height and size, phantom thickness and /-STRIP position for different IMT's (1.5, 3.0 and 7.5 mg 1/cm(2)). Near the phantom's periphery accuracy was found to be lower due to the breast-within-breast artifact. In the clinical setting (n = 5), workflow and image quality were not influenced by the /-STRIP. The mean IMT of these invasive breast cancers was 2.1 mg 1/cm(2) (range 1.3-3.4 mg 1/cm(2)). Malignant lesions showed significantly higher CGV's than benign lesions (p = 0.002).Conclusion: We showed in both phantom and clinical experiments that CESM quantification is feasible, without influencing workflow or image quality. The current CESM imaging protocol seems to be able to distinguish between benign and malignant breast lesions in terms of CGV.

The objective of this study was to demonstrate the capability of the high-energy in-line phase contrast imaging in detecting the breast tumors which are undetectable by conventional x-ray imaging but detectable by ultrasound. Experimentally, a CIRS multipurpose breast phantom with heterogeneous 50% glandular and 50% adipose breast tissue was imaged by high-energy in-line phase contrast system, conventional x-ray system and ultrasonography machine. The high-energy in-line phase contrast projection was acquired at 120 kVp, 0.3 mAs with the focal spot size of 18.3 μm. The conventional x-ray projection was acquired at 40 kVp, 3.3 mAs with the focal spot size of 22.26 μm. Both of the x-ray imaging acquisitions were conducted with a unique mean glandular dose of 0.08 mGy. As the result, the high-energy in-line phase contrast system was able to detect one lesion-like object which was also detected by the ultrasonography. This object was spherical shape with the length of about 12.28 mm. Also, the conventional x-ray system was not able to detect any objects. This result indicated the advantages provided by high-energy in-line phase contrast over conventional x-ray system in detecting lesion-like object under the same radiation dose. To meet the needs of current clinical strategies for high-density breasts screening, breast phantoms with higher glandular densities will be employed in future studies.

International audience; This paper deals with breast and head phantoms fabricated from 3D-printed structures and liquid mixtures whose complex permittivities are close to that of the biological tissues within a large frequency band. The goal is to enable an easy and safe manufacturing of stable-in-time detailed anthropomorphic phantoms dedicated to the test of microwave imaging systems to assess the performances of the latter in realistic configurations before a possible clinical application to breast cancer imaging or brain stroke monitoring. The structure of the breast phantom has already been used by several laboratories to test their measurement systems in the framework of the COST (European Cooperation in Science and Technology) Action TD1301-MiMed. As for the tissue mimicking liquid mixtures, they are based upon Triton X-100 and salted water. It has been proven that such mixtures can dielectrically mimic the various breast tissues. It is shown herein that they can also accurately mimic most of the head tissues and that, given a binary fluid mixture model, the respective concentrations of the various constituents needed to mimic a particular tissue can be predetermined by means of a standard minimization method.

An accurate measurement of the breast glandular fraction, or glandularity, is important for many research and clinical applications, such as breast cancer risk assessment. We propose a method to estimate the loss of glandular tissue detail due to the limited voxel size in tomographic images of the breast. CT images of a breast tissue specimen were acquired using a CdTe single photon counting detector (nominal pixel size of 60 μm) and using a monochromatic synchrotron radiation x-ray beam. Images were reconstructed using a filtered backprojection algorithm at seven different voxel sizes (range 60-420 µm, with a 60 µm step) and twelve groups of Regions of Interest (ROIs) with different percentage and patterns of glandular tissue were extracted. All ROIs within each group contained the same portion of the image (and therefore the same glandular fraction) reconstructed at a different voxel size. The glandular tissue was segmented and the glandularity calculated for all ROIs. A machine learning algorithm was trained on the glandularity values as a function of reconstruction voxel size. After the training was completed, the algorithm could estimate, given a tomographic breast image reconstructed at a given voxel size with a certain glandularity, the increase (or decrease) of glandularity if the same image were reconstructed with a smaller (or larger) voxel dimension. The algorithm was tested on six additional groups of ROIs, resulting in an average relative standard error between the calculated and estimated glandularity of 0.02 ± 0.016.

In this study, a new combined method to detect abnormality inside the biological phantom is presented. We describe a new approach to breast imaging based on diffuse optical tomography and optomechanical imaging. In this method, the diffusion of photons inside compressed breast phantom is used to detect the location of abnormalities. The variation of optical properties of phantom induced by compression can affect on diffusion of photons. Therefore, these variations of optical properties of phantom must be considered in this imaging method. In current study, the ability of this method to detect the location of tumor inside biological phantom is evaluated. The results show that the accuracy of this method is better than diffuse optical tomography.

The perspective of adding digital breast tomosynthesis (DBT) to standard mammography in screening raises concerns regarding the dose absorbed by the fibroglandular breast tissue. Thus, it is important to estimate accurately the mean glandular dose (MGD), although there are no standard protocols for dosimetry, concerning DBT. This study aims at introducing backscatter factors (BSF) to calculate the entrance surface air kerma (ESAK), directly on patients or phantoms, in order to be introduced in the formalism proposed by Dance et al. MCNPX simulations were performed, to mimic a DBT acquisition, for a wide range of X-ray spectra. A homogeneous breast phantom with 50 % of glandular tissue was considered and several thicknesses were evaluated. Dose measurements were performed, to validate and support the simulation results. The BSF may indicate a real MGD estimation in vivo for DBT examinations and contribute for the improvement of the current guidelines used in these applications.

Breast phantoms (BPs) are required to test and validate microwave breast imaging prototypes. For this purpose, a new BP made from carbon/rubber mixtures is proposed. These materials have: 1) electrical properties that are stable over time and representative of human target values and 2) mechanical properties that allow the material to be flexible and withstand reasonable stress. To characterize and optimize the carbon/rubber materials, samples made with varying carbon concentrations were created and the dielectric properties were measured. From these materials, a skin layer, fatty layer, glandular structures, and phantom tumors were cast from three-dimensional (3-D) printed molds and assembled into a complete BP. These phantoms mimic the anatomical structures of the breast, are reconfigurable for a variety of tests, and are easy to create in a typical lab environment. A microwave breast imaging prototype system was used to measure reflections from BPs. Comparison with reflections from human trials demonstrated that the phantom provides appropriate skin reflections. Phantoms incorporating glandular structures were imaged using a delay-and-sum technique. A response consistent with the position of the inclusions was observed. Overall, the carbon-based phantoms provide similar reflections to human tissue, and have proven useful for testing our imaging algorithms.

The objective of this study was to compare and analyse the absorbed dose profiles from the conformal radiotherapy planning and experimental dosimetry taken in a breast anthropomorphic and anthropometric phantom. Conformal radiotherapy planning was elaborated in the Treatment Planning System (TPS). EBT2 Gafchromic radiochromic films were applied as dosimeters, positioned internally and superficially in the breast phantom. The standard radiation protocol was applied in the breast phantom. The films were digitalised, and their responses were analysed in RGB. The optical densities were processed, reproducing the spatial dose distribution.

With imaging conditions that did not include x-ray source motion or patient motion during acquisition of the projection views, narrow-angle digital breast tomography (DBT) provided higher detection sensitivity and conspicuity than wide-angle DBT for subtle microcalcification clusters.

Purpose To develop an anthropomorphic breast phantom for use in credentialing of permanent breast seed implant brachytherapy. Methods and Materials A representative external contour and target volume was used as the basis of mold manufacturing for anthropomorphic breast phantom development. Both target and normal tissue were composed of gel-like materials that provide suitable computed tomography and ultrasound contrast for brachytherapy delivery. The phantoms were evaluated for consistency in construction (target location) and Hounsfield unit (computed tomography contrast). For both target and normal tissue, the speed of sound was measured and compared to the image reconstruction algorithm's expectation value. Five phantoms were imaged preimplant and postimplant to assess interphantom similarity as well as to evaluate the uncertainty in quantifying seed position. Results The average Hounsfield units of the target and normal tissue gels is −146 ± 5 and 23 ± 1, respectively. The average speed of sound of the target and normal tissue gels is 1485 ± 7 m/s and 1558 ± 9 m/s, respectively, resulting in an estimated 0.4 mm uncertainty in image guidance. The registration/deformation uncertainty was determined to be 0.8 mm. The standard combined uncertainty in assessing seed position spatial accuracy, also including a 0.9 mm estimate based on literature for seed localization, is estimated to be 1.3 mm. Conclusions The development of the anthropomorphic breast phantom and evaluation of both the consistency as well as overall seed position uncertainty illustrates the suitability of this phantom for use in brachytherapy end-to-end delivery and implant accuracy evaluation. When evaluating a user's implant accuracy, we estimate a standard combined uncertainty of 1.3 mm.

Purpose To design volume-specific breast phantoms from breast CT (bCT) data sets and estimate the associated normalized mean glandular dose coefficients for breast CT using Monte Carlo methods. Methods A large cohort of bCT data sets (N=215) was used to evaluate breast volume into quintiles (plus the top 5%). The average radius profile was then determined for each of the six volume-specific groups and used to both fabricate physical phantoms and generate mathematical phantoms (V1-V6; “V” denotes classification by volume). The MCNP6 Monte Carlo code was used to model a prototype bCT system fabricated at our institution; and this model was validated against physical measurements in the fabricated phantoms. The mathematical phantoms were used to simulate normalized mean glandular dose coefficients for both monoenergetic source photons “DgNCT(E)” (8–70 keV in 1 keV intervals) and polyenergetic x-ray beams “pDgNCT” (35–70 kV in 1 kV intervals). The Monte Carlo code was used to study the influence of breast size (V1 vs. V5) and glandular fraction (6.4% vs. 45.8%) on glandular dose. The pDgNCT coefficients estimated for the V1, V3, and V5 phantoms were also compared to those generated using simple, cylindrical phantoms with equivalent volume and two geometrical constraints including; (1) cylinder radius determined at the breast phantom chest wall “Rcw”; and (2) cylinder radius determined at the breast phantom center-of-mass “RCOM”. Results Satisfactory agreement was observed for dose estimations using MCNP6 compared with both physical measurements in the V1, V3, and V5 phantoms (R2 = 0.995) and reference bCT dose coefficients using simple phantoms (R2 = 0.999). For a 49 kV spectrum with 1.5 mm Al filtration, differences in glandular fraction (6.5% (5th percentile) vs. 45.8% (95th percentile)) had a 13.2% influence on pDgNCT for the V3 phantom, and differences in breast size (V1 vs. V5) had a 16.6% influence on pDgNCT for a breast composed of 17% (median) fibroglandular tissue. For cylindrical phantoms with a radius of RCOM the differences were 1.5%, 0.1%, and 2.1% compared with the V1, V3, and V5 phantoms, respectively. Conclusion Breast phantoms were designed using a large cohort of bCT data sets across a range of six breast sizes. These phantoms were then fabricated and used for the estimation of glandular dose in breast CT. The mathematical phantoms and associated glandular dose coefficients for a range of breast sizes (V1 – V6) and glandular fractions (5th to 95th percentiles) are available for interested users. This article is protected by copyright. All rights reserved.

International audience; In this paper, a Ultra-Wide-Band (UWB) antenna of dimensions 3cm x 3cm, designed to be used in direct contact with the breast is presented. The breast phantom model, on which the antenna was designed, consists of four layers (skin, fat, glandular tissues and muscle with their specific thicknesses) taking into account the dielectric properties for each layer and their dependence versus frequency. The antenna has been optimized for many reasons: enhance the matching to the human body and maximize the transfer of energy into the breast phantom to increase the detection potential.

Confocal imaging of a breast tumor phantom embedded in a 3D-printed breast phantom was demonstrated. 16 compact ultra-wideband (UWB) slot antennas were attached on the surface of the 3D-printed breast phantom and confocal imaging of 192 combinations was carried out by a radar-based breast cancer detection system. The breast adipose, glandular and tumor tissues were made of acrylonitrile butadien styrene plastic, the mixture of glycerin and water (saline) and bacon with the size of 10 mm × 10 mm × 10 mm.

Breast cancer is the most common disease among women in the word. However, despite the actual increase in the incidence rate, the death rate is decreasing, and this is mainly due to the improvement in screening techniques. Nowadays, one of the most common screening method is the X-ray mammography. However, its well-known limitations (woman exposition to ionizing radiations and painful compression) are requiring new imaging methods. In the last years, microwave imaging techniques have been proposed as a promising alternative. Moreover, systems adopting higher frequencies, in the mm-wave range, have been also proposed to augment the achievable spatial resolution. A key point for the development of these systems is the availability of suitable breast phantoms, which are fundamental to test the prototypes. This paper presents the preliminary results related to the dielectric characterization of materials suitable for the realization of a 3D-printing breast phantom, aimed to mime the tumorous tissues up to 50 GHz.

Although fat suppression technique is used in breast MRI, artifacts often appear owing to susceptibility and defective fat suppression effect after breast surgery. This is due to the abundance of adipose tissue in the breast as well as the region of air around the circumference of the excision site. Therefore, we have evaluated the optimal pad material for achieving fat suppression in breast MRI to reduce image artifacts and patient discomfort while maintaining breast shape. Oil of the solidity was used as the breast phantom material after segmental resection surgery. Five pad materials, including rice, ball bullets, glass beads, acrylic beads, and bath salts were used to fill the defects. Fat-suppressed, T1-weighted, three-dimensional imaging was performed using a breast array coil. Images with and without the five pad materials, were evaluated physically, visually, and by contact. Physical evaluation consisted of measuring the maximum signal and standard deviation in the regions of interest (ROIs). Discomfort and the amount of perceived resistance were evaluated during contact evaluation by inserting a finger into each pad material. In results, glass beads and bath salts produced a significantly larger fat suppression effect in the ROIs. Visual and contact evaluation also highlighted the benefits of glass beads, the latter demonstrating a significant decrease in discomfort and perceived resistance. In conclusion, we consider glass beads as the optimal pad material for fat suppression in breast MRI after surgery.

A silicone-based composite breast phantom is fabricated to be used as an education model in ultrasonography training. A matrix of silicone formulations is tracked to mimic the ultrasonography and tactile response of human breast tissue. The performance of two different additives: (i) silicone oil and (ii) vinyl-terminated poly (dimethylsiloxane) (PDMS) are monitored by a home-made acoustic setup. Through the use of 75 wt% vinyl-terminated PDMS in two-component silicone elastomer mixture, a sound velocity of 1.29 +/- 0.09 x 10(3) m/s and an attenuation coefficient of 12.99 +/- 0.08 dB/cm-values those match closely to the human breast tissue-are measured with 5 MHz probe. This model can also be used for needle biopsy as well as for self-exam trainings. Herein, we highlight the fabrication of a realistic, durable, accessible, and cost-effective training platform that contains skin layer, inner breast tissue, and tumor masses. (C) 2018 Elsevier B.V. All rights reserved.

Purposes: This work consists of studying the interseed and tissue composition effects for two model iodine seeds: the IBt Interseed‐125 and the 6711 model seed. Materials & Methods: Three seeds were modeled with the MCNP MC code in a water sphere to evaluate the interseed effect. The dose calculated at different distances from the centre was compared to the dose summed when the seeds were simulated separately. The tissue composition effect was studied calculating the radial dose function for different tissues. Before carrying out post‐implant studies, the absolute dose calculated by MC was compared to experiment results: with LiF TLDs in an acrylic breast phantom and with an EBT Gafchromic film placed in a water tank. Afterwards, the TG‐43 approximation effects were studied for a prostate and breast post‐implant. Results and Discussion: The interseed effect study shows that this effect is more important for model 6711 (15%) than for IBt (10%) due to the silver rod in 6711. For both seed models the variations of the radial dose function as a function of the tissue composition are quasi similar. The absolute dose comparisons between MC calculations and experiments give good agreement (inferior to 3% in general). For the prostate and breast post‐implant studies, a 10% difference between MC calculations and the TG‐43 is found for both models of seeds. Conclusion: This study shows that the differences in dose distributions between TG43 and MC are quite similar for the two models of seeds and are about 10% for the studied post‐implant treatments.

Physical breast phantoms are used for imaging evaluation studies with 2D and 3D breast x-ray systems, serving as surrogates for human patients. However, there is a presently a limited selection of available phantoms that are realistic, in terms of containing the complex tissue architecture of the human breast. In addition, not all phantoms can be successfully utilized for both 2D and 3D breast imaging. Additionally, many of the phantoms are uniform or unrealistic in appearance, expensive, or difficult to obtain. The purpose of this work was to develop a new method to generate realistic physical breast phantoms using easy to obtain and inexpensive materials. First, analytical modeling was used to design a virtual model, which was then compressed using finite element modeling. Next, the physical phantom was realized through inkjet printing with a standard inkjet printer using parchment paper and specialized inks, formulated using silver nanoparticles and a bismuth salt. The printed phantom sheets were then aligned and held together using a custom designed support plate made of PMMA, and imaged on clinical FFDM and DBT systems. Objects of interest were also placed within the phantom to simulate microcalcifications, pathologies that often occur in the breast. The linear attenuation coefficients of the inks and parchment were compared against tissue equivalent samples and found to be similar to breast tissue. The phantom is promising for use in imaging studies and developing QC protocols.

This paper presents a model and the validation of microwave radiation into the surrounding breast tissues, these patterns are obtained by applying ablation therapy.

In this work we present an experimental study of qualitative microwave imaging algorithms for breast cancer detection. All the experiments are carried out with a 3-D printed realistic breast phantom filled with designed tissue mimicking liquids. In the following, the first experimental results using the Truncated Singular Value Decomposition (TSVD) scheme and the Linear Sampling Method (LSM) reconstructions are reported.

The extraction of microstructures (like microcalcifications or masses) from a DBT phantom can be used for image quality assessment. A complete specification includes exact positions and dimensions of the microstructures, which is not always available. We propose a technique to estimate the required ground truth data from a set of multiple acquisitions. A 3D registration algorithm for DBT data is used to identify different breast phantom components and to perfectly align microstructures within the phantom. The registered data, showing variations of the same ground truth structures, is then combined to an estimate of the microstructures. This approach could be shown to improve the registration result itself, and to enable the determination of the actual parameters of the microstructures.