3D Breast Imaging Research Articles

Integrated Dataset-Preparation System for ML-Based Medical Image Diagnosis with High Clinical Applicability in Various Modalities and Diagnoses

This study proposed an integrated dataset-preparation system for ML-based medical image diagnosis, offering high clinical applicability in various modalities and diagnostic purposes. With the proliferation of ML-based computer-aided diagnosis using medical images, massive datasets should be prepared. Lacking of a standard procedure, dataset-preparation may become ineffective. Besides, on-demand procedures are locked to a single image-modality and purpose. For these reasons, we introduced a dataset-preparation system applicable for a variety of modalities and purposes. The system consisted of a common part including incremental anonymization and cross annotation for preparing anonymized unprocessed data, followed by modality/subject-dependent parts for subsequent processes. The incremental anonymization was carried out in batch after the image acquisition. Cross annotation enabled collaborative medical specialists to co-generate annotation objects. For quick observation of dataset, thumbnail images were created. With anonymized images, preprocessing was accomplished by complementing manual operations with automatic operations. Finally, feature extraction was automatically performed to obtain data representation. Experimental results on two demonstrative systems dedicated to esthetic outcome evaluation of breast reconstruction surgery from 3D breast images and tumor detection from breast MRI images were provided. The proposed system successfully prepared the 3D breast-mesh closures and their geometric features from 3D breast images, as well as radiomics and likelihood features from breast MRI images. The system also enabled effective voxel-by-voxel prediction of tumor region from breast MRI images using random-forest and k-nearest-neighbors algorithms. The results confirmed the efficiency of the system in preparing dataset with high clinical applicability regardless of the image modality and diagnostic purpose.

Spiral breast computed tomography with a photon-counting detector (SBCT): The future of breast imaging?

Dedicated breast computed tomography (BCT) is an emerging breast imaging modality. The latest development has been the introduction of a spiral breast computed tomography scanner equipped with a photon-counting detector (SBCT).SBCT promises multiple advantages: Unlike conventional mammography, contrast enhanced spectral mammography (CESM: both 2D), and digital breast tomosynthesis (DBT: pseudo 3D), SBCT enables 3D breast imaging without tissue overlap. SBCT achieves high isotropic spatial resolution of breast tissue enabling the assessment of both soft tissue and microcalcifications. Similar to CESM and MRI, SBCT supports contrast-enhanced imaging, enabling the assessment of breast neovascularization. Unlike mammography and its derived methods (CESM, DBT), SBCT does not require compression of the breast. Accordingly, women consistently report significantly increased patient comfort compared to mammography in a previous investigation.Radiation safety is crucial in breast imaging. Studies showed different results in terms of dose, with some staying within the limits of two-view FFDM defined by the ACR and others exceeding the limit by up to 21%. Therefore, a higher radiation dose compared to state-of-the-art mammography and DBT systems has to be acknowledged.SBCT is currently under scientific investigation in multiple trials. Three major indications are currently explored: Whereas our colleagues in Zurich/Switzerland investigate the role of SBCT for opportunistic screening, in our department SBCT is mainly indicated for the work-up of equivocal lesions, and for preoperative staging.In this narrative review, we summarize the concepts of SBCT and potential implications for patient care. We report on our initial clinical experience with the technology and outline future developments of SBCT.

Satisfaction survey on a preoperative explanation method using three-dimensional breast imaging for breast cancer patients considering breast-conserving surgery.

Although one of the essential factors in surgical shared decision-making is the body image, the breast morphology after breast-conserving surgery is particularly difficult to explain in a uniform manner due to large individual differences. Patients with breast cancer eligible for breast-conserving surgery (BCS) were recruited between June 2020 and October 2021. We surveyed the patients' satisfaction with our method of explaining the likely breast morphology after BCS using three-dimensional (3D) breast imaging in the form of a questionnaire. A total of 162 patients were enrolled, and 137 (84.6%) answered the questionnaire. One hundred and sixteen patients (84.6%) answered that they were very satisfied or satisfied with our explanation method, and 100 (73.0%) patients were very satisfied or satisfied with the 3D breast imaging. Some patients answered that 3D breast imaging helped them prepare for BCS, or on the contrary, made them choose mastectomy with breast reconstruction because the deformation likely with BCS was considered unacceptable. Only a few patients who underwent BCS felt that their postoperative morphology was more deformed than the preoperatively imagined one. Our results suggest that our preoperative explanation method using 3D breast imaging was useful for shared decision-making.

Portable NMR for quantification of breast density in vivo: Proof-of-concept measurements and comparison with quantitative MRI

Mammographic Density (MD) is the degree of radio-opacity of the breast in an X-ray mammogram. It is determined by the Fibroglandular: Adipose tissue ratio. MD has major implications in breast cancer risk and breast cancer chemoprevention. This study aimed to investigate the feasibility of accurate, low-cost quantification of MD in vivo without ionising radiation.We used single-sided portable nuclear magnetic resonance (“Portable NMR”) due to its low cost and the absence of radiation-related safety concerns. Fifteen (N = 15) healthy female volunteers were selected for the study and underwent an imaging routine consisting of 2D X-ray mammography, quantitative breast 3T MRI (Dixon and T1-based 3D compositional breast imaging), and 1D compositional depth profiling of the right breast using Portable NMR. For each participant, all the measurements were made within 3–4 h of each other. MRI-determined tissue water content was used as the MD-equivalent quantity. Portable NMR depth profiles of tissue water were compared with the equivalent depth profiles reconstructed from Dixon and T1-based MR images, which were used as the MD-equivalent reference standard.The agreement between the depth profiles acquired using Portable NMR and the reconstructed reference-standard profiles was variable but overall encouraging. The agreement was somewhat inferior to that seen in breast tissue explant measurements conducted in vitro, where quantitative micro-CT was used as the reference standard. The lower agreement in vivo can be attributed to an uncertainty in the positioning of the Portable NMR sensor on the breast surface and breast compression in Portable NMR measurements.The degree of agreement between Portable NMR and quantitative MRI is encouraging. While the results call for further development of quantitative Portable NMR, they demonstrate the in-principle feasibility of Portable NMR-based quantitative compositional imaging in vivo and show promise for the development of safe and low-cost protocols for quantification of MD suitable for clinical applications.

Feasibility of determining mammography dose using LuSy dosimeter

Mammography is a radiological examination that utilises low-energy X-ray to detect breast cancer. The techniques include full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT), which produce 2D and 3D breast images, respectively. Mean glandular dose (MGD) is used to describe the dose delivered by these techniques because it estimates the photon absorption by glandular tissues in the breast. This study aims to calibrate, characterise and determine the feasibility of measuring MGD using an in-house developed, real-time fibre-optic dosimeter called the LuSy dosimeter. LuSy was calibrated against a solid-state mammography dosimeter for three target-filter combinations of W/Rh, W/Ag and W/Al. Subsequently, characterisation towards mammography radiation was carried out. Finally, MGD was measured using LuSy and subsequently compared with the readings of a solid-state detector and those estimated by the mammography machine. The measured calibration coefficient was 342.10, 380.35 and 447.68 counts/mGy for W/Rh, W/Ag and W/Al target-filter combinations, respectively. For MGD, both LuSy and the mammography dosimeter measured a higher dose compared with the machine console. The mean deviation between LuSy and machine console was 14.72%. Meanwhile, the mean deviation between the mammography dosimeter and the machine console was 19.5%. In conclusion, the LuSy may be calibrated to measure low-energy X-ray, and its MGD reading is comparable with a solid-state dosimeter.

Variability of response to early puberty induction demonstrated by transverse uterine diameter measurement and a novel method of 3D breast imaging.

Induction of puberty with exogenous oestrogen results in considerable variability in final uterine and breast volumes. We set out to quantify the variability of these two outcome measures with a view to establishing monitoring methods that could be used to individualise treatment protocols. A prospective observational study. Sixteen participants with pubertal delay and primary amenorrhoea, due to hypogonadism were recruited from paediatric gynaecology and endocrinology clinics at University College London Hospital. A standardised protocol of transdermal 17β oestradiol (17βE) was used (Evorel™), with a starting dose of 12.5 mcg increasing to 25 mcg (patch changed twice weekly) after 4 months. Follow up was every 2 months for a total of 8 months. Uterine dimensions using ultrasound, oestradiol concentrations and breast development assessed by both Tanner staging and 3D photographic imaging. After 8 months of treatment, the changes in oestradiol concentrations (0-174 pmol), uterine volume growth (4.4-16.4 ml) and breast volume (1.76-140.1 ml) varied greatly between individuals. Of uterine parameters, transverse uterine diameter was most closely associated with serum oestradiol levels at 8 months (beta standardised coefficient = 0.80, p = .001). Change in breast volume was associated with age of treatment initiation (beta standardised coefficient 0.55 p = .04). We demonstrate variation in response to exogenous oestrogen, emphasising the necessity for individualised dose titration. In the absence of sensitive oestradiol assays, uterine transverse measurements may be used as a surrogate marker of oestrogen sensitivity to guide early dose adjustment. 3D breast imaging may provide a quantitative assessment of breast development to complement Tanner breast staging.

Comparisons of glandular breast dose between digital mammography, tomosynthesis and breast CT based on anthropomorphic patient-derived breast phantoms

PurposeTo evaluate the bias to the mean glandular dose (MGD) estimates introduced by the homogeneous breast models in digital breast tomosynthesis (DBT) and to have an insight into the glandular dose distributions in 2D (digital mammography, DM) and 3D (DBT and breast dedicated CT, BCT) x-ray breast imaging by employing breast models with realistic glandular tissue distribution and organ silhouette. MethodsA Monte Carlo software for DM, DBT and BCT simulations was adopted for the evaluation of glandular dose distribution in 60 computational anthropomorphic phantoms. These computational phantoms were derived from 3D breast images acquired via a clinical BCT scanner. Resultsg·c·s·T conversion coefficients based on homogeneous breast model led to a MGD overestimate of 18% in DBT when compared to MGD estimated via anthropomorphic phantoms; this overestimate increased up to 21% for recently computed DgNDBT conversion coefficients. The standard deviation of the glandular dose distribution in BCT resulted 60% lower than in DM and 55% lower than in DBT. The glandular dose peak – evaluated as the average value over the 5% of the gland receiving the highest dose – is 2.8 times the MGD in DM, this factor reducing to 2.6 and 1.6 in DBT and BCT, respectively. ConclusionsConventional conversion coefficients for MGD estimates based on homogeneous breast models overestimate MGD by 18%, when compared to MGD estimated via anthropomorphic phantoms. The ratio between the peak glandular dose and the MGD is 2.8 in DM. This ratio is 8% and 75% higher than in DBT and BCT, respectively.

Virtual Clinical Trials in 2D and 3D X-ray Breast Imaging and Dosimetry: Comparison of CPU-Based and GPU-Based Monte Carlo Codes.

Simple SummaryVirtual clinical trials in X-ray breast imaging may permit substantial reduction of the costs, times, and exposure risk to patient of clinical trials. Monte Carlo simulation techniques are increasingly adopted for VCT in breast imaging and dosimetry studies. This work aims to compare three different platforms for breast VCT studies, to develop real-time virtual DM, DBT and BCT examinations, where the in-silico image acquisition process takes a computational time comparable to that typical of a corresponding real clinical examination.Computational reproductions of medical imaging tests, a form of virtual clinical trials (VCTs), are increasingly being used, particularly in breast imaging research. The accuracy of the computational platform that is used for the imaging and dosimetry simulation processes is a fundamental requirement. Moreover, for practical usage, the imaging simulation computation time should be compatible with the clinical workflow. We compared three different platforms for in-silico X-ray 3D breast imaging: the Agata (University & INFN Napoli) that was based on the Geant4 toolkit and running on a CPU-based server architecture; the XRMC Monte Carlo (University of Cagliari) that was based on the use of variance reduction techniques, running on a CPU hardware; and the Monte Carlo code gCTD (University of Texas Southwestern Medical Center) running on a single GPU platform with CUDA environment. The tests simulated the irradiation of cylindrical objects as well as anthropomorphic breast phantoms and produced 2D and 3D images and 3D maps of absorbed dose. All the codes showed compatible results in terms of simulated dose maps and imaging values within a maximum discrepancy of 3%. The GPU-based code produced a reduction of the computation time up to factor 104, and so permits real-time VCT studies for X-ray breast imaging.

Dataset of patient-derived digital breast phantoms for in silico studies in breast computed tomography, digital breast tomosynthesis, and digital mammography.

To present a dataset of computational digital breast phantoms derived from high-resolution three-dimensional (3D) clinical breast images for the use in virtual clinical trials in two-dimensional (2D) and 3D x-ray breast imaging. Uncompressed computational breast phantoms for investigations in dedicated breast CT (BCT) were derived from 150 clinical 3D breast images acquired via a BCT scanner at UC Davis (California, USA). Each image voxel was classified in one out of the four main materials presented in the field of view: fibroglandular tissue, adipose tissue, skin tissue, and air. For the image classification, a semi-automatic software was developed. The semi-automatic classification was compared via manual glandular classification performed by two researchers. A total of 60 compressed computational phantoms for virtual clinical trials in digital mammography (DM) and digital breast tomosynthesis (DBT) were obtained from the corresponding uncompressed phantoms via a software algorithm simulating the compression and the elastic deformation of the breast, using the tissue's elastic coefficient. This process was evaluated in terms of glandular fraction modification introduced by the compression procedure. The generated cohort of 150 uncompressed computational breast phantoms presented a mean value of the glandular fraction by mass of 12.3%; the average diameter of the breast evaluated at the center of mass was 105mm. Despite the slight differences between the two manual segmentations, the resulting glandular tissue segmentation did not consistently differ from that obtained via the semi-automatic classification. The difference between the glandular fraction by mass before and after the compression was 2.1% on average. The 60 compressed phantoms presented an average glandular fraction by mass of 12.1% and an average compressed thickness of 61mm. The generated digital breast phantoms are stored in DICOM files. Image voxels can present one out of four values representing the different classified materials: 0 for the air, 1 for the adipose tissue, 2 for the glandular tissue, and 3 for the skin tissue. The generated computational phantoms datasets were stored in the Zenodo public repository for research purposes (http://doi.org/10.5281/zenodo.4529852, http://doi.org/10.5281/zenodo.4515360). The dataset developed within the INFN AGATA project will be used for developing a platform for virtual clinical trials in x-ray breast imaging and dosimetry. In addition, they will represent a valid support for introducing new breast models for dose estimates in 2D and 3D x-ray breast imaging and as models for manufacturing anthropomorphic physical phantoms.

The Effect of Arm Position on Breast Volume Measurement Using Three-dimensional Imaging.

Three-dimensional (3D) imaging offers an objective and quantitative way to evaluate the breast volume. In this study, we aimed to investigate whether arm position can be a factor influencing the measurement of breast volume and which arm position is more stable when using 3D breast imaging in evaluating the fat volume retention rate in autologous fat grafting for breast augmentation. Patients undergoing breast augmentation with autologous fat grafting in our department were selected for the first part of this study. Preoperative 3D breast imaging was performed at three different arm positions: at the sides, akimbo and with hands on the head. Scans on each arm position were repeated on the first day after surgery, taking six scans in total. Breast volume change (BVC) was compared before and after surgery. The patients planning to receive bilateral mammaplasty in our department were selected for the second part of this study. Two repeated 3D scans were performed at the sides, akimbo and hands on the head, and then, the breast volume change error (BVCE) was compared. Twenty-five patients (n = 50 breasts) were included in the first part of study. For the patients who received 100-200ml fat injection, compared with hands on the head, a statistically significant difference in the average BVC was found at the sides and akimbo (p = 0.02). For the patients receiving more than 200ml fat injection, there was no statistically significant difference between the groups (p > 0.05). Twenty-six patients (n = 52 breasts) were enrolled in the second part. For the average BVCE, there was no significant difference between the groups (p = 0.11). The arm position during 3D breast imaging, to some extent, affects the evaluation of BVC after breast augmentation using autologous fat grafting, particularly for patients receiving less fat grafting. The arm position should be kept consistent when using 3D breast imaging in evaluating the fat volume retention rate. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266.

Interpretation on Breast Cancer Generation in 2D & 3D Images by Skeletonization Algorithm

The present usage and values obtained clinically on breast cancer expansion and assessment techniques are tragically not upto the mark. In this advanced world, 3D mammography algorithm is not used till now for identifying cancer expansion. A specialized algorithm called skeletonization algorithm is used after identifying the cancer in women’s breast and estimating the direction of spreading cancer and its malignancy. For this 2D and 3D breast images are taken for clinical experiment.

Characterization of a multi-pinhole molecular breast tomosynthesis scanner

In recent years, breast imaging using radiolabelled molecules has attracted significant interest. Our group has proposed a multi-pinhole molecular breast tomosynthesis (MP-MBT) scanner to obtain 3D functional molecular breast images at high resolutions. After conducting extensive optimisation studies using simulations, we here present a first prototype of MP-MBT and evaluate its performance using physical phantoms. The MP-MBT design is based on two opposing gamma cameras that can image a lightly compressed pendant breast. Each gamma camera consists of a 250 × 150 mm2 detector equipped with a collimator with multiple pinholes focusing on a line. The NaI(Tl) gamma detector is a customised design with 3.5 mm intrinsic spatial resolution and high spatial linearity near the edges due to a novel light-guide geometry and the use of square PMTs. A volume-of-interest is scanned by translating the collimator and gamma detector together in a sequence that optimises count yield from the scan region. Derenzo phantom images showed that the system can reach 3.5 mm resolution for a clinically realistic 99mTc activity concentration in an 11-minute scan, while in breast phantoms the smallest spheres visible were 6 mm in diameter for the same scan time. To conclude, the experimental results of the novel MP-MBT scanner showed that the setup had sub-centimetre breast tumour detection capability which might facilitate 3D molecular breast cancer imaging in the future.

The Use of a 3D Simulator Software and 3D Printed Biomodels to Aid Autologous Breast Reconstruction.

Aesthetically pleasing and symmetrical breasts are the goal of reconstructive breast surgery. However, multiple procedures are sometimes needed to improve a reconstructed breast's symmetry and appearance. Since all breasts vary in terms of volume, height, width, projection, orientation, and shape, the lack of attention to these details at the moment of flap shaping in autologous reconstruction can lead to poor results. Recent advances in 3-dimensional (3D) surface imaging and printing technologies have allowed for improvement in autologous breast reconstruction symmetry. While 3D printing technology is becoming faster, more accurate, and less expensive, the technology required to obtain proper 3D breast images remains expensive, including laser scanners or 3D photogrammetric cameras. In this study, we present a novel use of an aesthetic surgery simulator software as an affordable alternative to obtaining 3D breast images and creating 3D printed biomodels to aid in the precise shaping of the flap. This approach aims to optimize aesthetic results in autologous breast reconstruction avoiding surgical revisions and reducing surgical times. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Normalized glandular dose coefficients in mammography, digital breast tomosynthesis and dedicated breast CT

PurposeTo provide mean glandular dose (MGD) estimates via Monte Carlo (MC) simulations as a function of the breast models and scan parameters in mammography, digital breast tomosynthesis (DBT) and dedicated breast CT (BCT). MethodsThe MC code was based on GEANT4 toolkit. The simulated compressed breast was either a cylinder with a semi-circular section or ad hoc shaped for oblique view (MLO). In DBT we studied the influence of breast models and exam parameters on the T-factors (i.e. the conversion factor for the calculation of the MGD in DBT from that for a 0-degree projection), and in BCT we investigated the influence on the MGD estimates of the ion chamber volume used for the air kerma measurements. ResultsIn mammography, a model representative of a breast undergoing an MLO view exam did not produce substantial differences (0.4%) in MGD estimates, when compared to a conventional cranio-caudal (CC) view breast model. The beam half value layer did not present a significant influence on T-factors in DBT (<0.8%), while the skin model presented significant influence on MGD estimates (up to 3.3% at 30 degrees scan angle), increasing for larger scan angles. We derived a correction factor for taking into account the different ion chamber volume used in MGD estimates in BCT. ConclusionsA series of MC code modules for MGD estimates in 2D and 3D breast imaging have been developed in order to take into account the most recent advances in breast models.

The Effect of Respiration on Breast Measurement Using Three-dimensional Breast Imaging

Three-dimensional (3D) imaging offers new opportunities to enable objective and quantitative analysis of the breast. Unlike scanning of rigid objects, respiration may be one of the factors that can influence the measurement of breast when using 3D imaging. In this study, we aimed to investigate how the different respiratory phases affect 3D morphologic and volumetric evaluations of the breast. We performed preoperative 3D breast imaging at the end of expiration (EE) and the end of inspiration (EI). We repeated scans on each respiratory phase, taking four scans in total (EE1, EE2 and EI1, EI2). Using Geomagic Studio 12 software, measurements from the different respiratory phases (EE1 and EI1) were compared for differences in the linear distances of breast. Breast volumetric change error (BVCE) was measured between EE1 and EE2 (R1) and between EI1 and EI2 (R2). A multilevel model was used to analyze the difference of linear-distances parameters between EE1 and EI1 and a paired sample t-test was used to analyze the difference between R1 and R2. Our study included 13 Chinese women (26 breasts) with a mean age of 32.6 ± 6.3years. Compared with EI, EE showed a longer sternal notch to the level of the inframammary fold and shorter nipple to midline (p < 0.05). During EI, breast projection increased by 0.23cm (95% CI - 0.39, - 0.08) and breast base width increased by 0.27cm (95% CI - 0.46, - 0.09). The position of the nipple moved by 0.18cm (95% CI - 0.34, - 0.03) laterally, 0.41cm (95% CI 0.18, 0.64) cranially, and 0.71cm (95% CI - 0.92, - 0.51) anteriorly. Although there was no significant difference in BVCE between EE and EI, the result seen with EE appeared to be more consistent. The results of this study demonstrate that there was no difference in breast volume results when patients are in the expiratory or inspiratory state during 3D breast imaging. This study, however, holds potential benefits to both surgical practice as well as the 3D imaging industry. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Advances in digital and physical anthropomorphic breast phantoms for x-ray imaging.

With the advent of three-dimensional (3D) breast imaging modalities such as digital breast tomosynthesis (DBT) and dedicated breast CT (bCT), research into new anthropomorphic breastphantoms has accelerated. These breast phantoms are important for the optimization of new breast imaging systems, assessing new regulatory submissions to prove safety and effectiveness, and for developing new approaches to acceptance and constancy testing of 3D breast imaging systems. This paper provides a review of current research investigating both digital and physical breast phantom development for use in x-ray based imaging. Two approaches for designing anthropomorphic, digital breast phantoms are discussed, procedural model-based phantom generation, where breast features are expressed using mathematical models, and patient-based generation, where breast structures from tissue specimens or patient-based breast MR or CT volumes are segmented. Following this discussion, a review of physical anthropomorphic phantoms is given, with emphasis on the advantages and disadvantages present with each approach. This paper provides a summary of the state-of-the-art in anthropomorphic breast phantom development for x-ray breast imaging. The primary advantage of model-based digital phantoms is that an unlimited number of phantoms with varying size, shape, and density can be generated. Current research on model-based breast phantoms is producing more and more realistic breast models; however, they probably are not yet able to pass the so-called "fool the radiologist" visualization test. Empirical patient-based breast phantoms are typically based on clinical breast CT data and look more realistic. However, clinical breast CT images have limited spatial resolution and thus do not always portray the finer details in the breast. A number of innovative solutions have been proposed for fabricating physical anthropomorphic breast phantoms based on digital phantom models; however, a number of challenges remain, including realistic modeling of x-ray attenuation properties and accurately representing high-frequency structures within breast.

OA216] Development of breast tumours models database

Purpose We present the development and the current state of the MaXIMA Breast Tumours Models’ Database, which is intended to provide researchers with both segmented and mathematically modelled realistic in shape computer-based breast tumours. Methods The database contains various 3D images of breast cancers of irregular shapes, collected from routine patient examinations or dedicated scientific experiments. It also contains images of simulated tumour models. To extract the 3D shapes of the breast cancers from patient images, an in–house developed and well evaluated segmentation algorithm was applied on 60 tomosynthesis sets from patients diagnosed with malignant and benign lesions. In addition, three breast mastectomy cases scanned at a CT system were added. This algorithm includes a series of image processing operations and region-growing techniques with minimal interaction from the user to find and segment the areas of the lesions. Modelled computational breast tumours are generated following different approaches and also stored in the database. Each record in the database is supported with relevant information, e.g. voxel size and resolution, matrix size, geometrical centre, etc. Results The MaXIMA Imaging Database currently contains 68 unique breast cancer models obtained by segmentation of 3D patient breast tomosynthesis images; 8 models obtained by segmentation of 3D micro CT images of biopsy specimens; and 20 models based on mathematical algorithm. An application of the tumour models is to insert them into computationally generated healthy breast phantom generated with dedicated software tools (e.g. the BreastSimulator tool). The resulted combined computational breast models are used to study the visibility of breast tumours in 3D breast imaging techniques. This 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. The database interface is web-based, i.e. is platform independent, user friendly and is indented to be made freely accessible through internet after the completion of the MaXIMA project. Conclusions The developed database serves as an imaging data source for researchers, working on breast imaging and early breast cancer detection with the help of existing or newly developed imaging modalities.

Chances and limitations of a low-cost mobile 3D scanner for breast imaging in comparison to an established 3D photogrammetric system

In search of new possibilities in 3D surface imaging, several nonmedical scanning systems have been assessed for their implementation in plastic surgery. The aim of this study was to compare a new affordable 3D imaging consumer product with an established medical 3D imaging system for objective 3D breast imaging. We compared a low-cost mobile, handheld scanner against an established medical 3D surface imaging system. Forty-two female patients who underwent different types of breast surgery were captured in a 3D view with both devices. Digital breast measurement, volume measurement, and breast surface-to-surface analysis were done using Mirror software. Repeatability was assessed by repeated 3D scans of the torso and surface-to-surface analysis. Digital breast measurement showed low differences with good-to-excellent correlation between both devices. Mean breast volume difference was small (-5.11 ± 32.10 mL) within the 95% limits of agreement. Surface-to-surface analysis yielded a higher surface deviation in the lower breast quadrants (1.62 ± 0.80 mm root mean square [RMS] error and 1.81 ± 0.88 mm RMS error) than in the upper breast quadrants. Repeatability was satisfactory with a mean of 0.636 ± 0.279 mm RMS error. Affordable mobile surface scanners may offer new perspectives in the future for 3D breast imaging. Although surface acquisition was sufficient for breast measurements in comparison to an established system, the lack of appropriate medical software for patient consultation next to moderate texture quality needs to be improved for wider acceptance in plastic surgery.

Monte Carlo evaluation of glandular dose in cone-beam X-ray computed tomography dedicated to the breast: Homogeneous and heterogeneous breast models

PurposeIn cone-beam computed tomography dedicated to the breast (BCT), the mean glandular dose (MGD) is the dose metric of reference, evaluated from the measured air kerma by means of normalized glandular dose coefficients (DgNCT). This work aimed at computing, for a simple breast model, a set of DgNCT values for monoenergetic and polyenergetic X-ray beams, and at validating the results vs. those for patient specific digital phantoms from BCT scans. MethodsWe developed a Monte Carlo code for calculation of monoenergetic DgNCT coefficients (energy range 4.25–82.25 keV). The pendant breast was modelled as a cylinder of a homogeneous mixture of adipose and glandular tissue with glandular fractions by mass of 0.1%, 14.3%, 25%, 50% or 100%, enveloped by a 1.45 mm-thick skin layer. The breast diameter ranged between 8 cm and 18 cm. Then, polyenergetic DgNCT coefficients were analytically derived for 49-kVp W-anode spectra (half value layer 1.25–1.50 mm Al), as in a commercial BCT scanner. We compared the homogeneous models to 20 digital phantoms produced from classified 3D breast images. ResultsPolyenergetic DgNCT resulted 13% lower than most recent published data. The comparison vs. patient specific breast phantoms showed that the homogeneous cylindrical model leads to a DgNCT percentage difference between −15% and +27%, with an average overestimation of 8%. ConclusionsA dataset of monoenergetic and polyenergetic DgNCT coefficients for BCT was provided. Patient specific breast models showed a different volume distribution of glandular dose and determined a DgNCT 8% lower, on average, than homogeneous breast model.

X-ray-induced acoustic computed tomography for 3D breast imaging: A simulation study.

The objective of this study is to demonstrate the feasibility of x-ray-induced acoustic computed tomography (XACT) for early breast un-palpable microcalcification (μCa) detection in three dimensions (3D). The proposed technique provides the true 3D imaging for breast volume which overcomes the disadvantage of the tissue superposition in mammography. A 3D breast digital phantom was rendered from two-dimensional (2D) breast CT slices. Three different tissue types, including the skin, adipose tissue, and glandular tissue, were labeled in the 3D breast phantom. μCas were manually embedded in different locations inside the breast phantom. For each tissue type, the initial pressure rise caused by the x-ray-induced acoustic (XA) effect was calculated according to its themoacoustic properties. The XA wave's propagation from the point of generation and its detection by ultrasound detector array were simulated by Matlab K-Wave toolbox. The 3D breast XACT volume with μCa was acquired without tissue superposition, and the system was characterized by μCas placed at different locations. The simulation results illustrated that the proposed breast XACT system has the ability to show the μCa cluster in 3D without any tissue superposition. Meanwhile, μCa as small as 100 μm in size can be detected with high imaging contrast, high signal to noise ratio (SNR), and high contrast to noise ratio (CNR). The dose required by the proposed XACT configuration was calculated to be 0.4 mGy for a 4.5 cm-thick compressed breast. This is one-tenth of the dose level of a typical two-view mammography for a breast with the same compression thickness. The initial exploration for the feasibility of 3D breast XACT has been conducted in this study. The system feasibility and characterization were illustrated through a 3D breast phantom and simulation works. The 3D breast XACT with the proposed system configuration has great potential to be applied as a low-dose screening and diagnostic technique for early un-palpable lesion in the breast.