KEYWORDS: Digital breast tomosynthesis, Image quality, Breast, Image restoration, Prototyping, 3D image reconstruction, Sensors, X-rays, X-ray sources, Super resolution
A next generation tomosynthesis (NGT) prototype has been developed to investigate alternative scanning geometries for digital breast tomosynthesis (DBT). Performance of NGT acquisition geometries is evaluated to validate previous phantom experiments. Two custom NGT acquisition geometries were compared to a conventional DBT geometry. Noise power spectra are used to describe features of specimen image reconstructions and compare acquisition geometries. NGT acquisition geometries improve high-frequency performance with superior isotropic super resolution, reduced out-of-plane blurring, and better overall reconstruction quality. NGT combines benefits of narrow- and wide-angle tomosynthesis in a single scan improving high-frequency spatial resolution and out-of-plane blurring, respectively.
KEYWORDS: Breast, Digital breast tomosynthesis, 3D modeling, Skin, Fractal analysis, Tissues, Prototyping, Computer simulations, Signal attenuation, Principal component analysis
Virtual clinical trials (VCTs) have been used widely to evaluate digital breast tomosynthesis (DBT) systems. VCTs require realistic simulations of the breast anatomy (phantoms) to characterize lesions and to estimate risk of masking cancers. This study introduces the use of Perlin-based phantoms to optimize the acquisition geometry of a novel DBT prototype. These phantoms were developed using a GPU implementation of a novel library called Perlin-CuPy. The breast anatomy is simulated using 3D models under mammography cranio-caudal compression. In total, 240 phantoms were created using compressed breast thickness, chest-wall to nipple distance, and skin thickness that varied in a {[35, 75], [59, 130), [1.0, 2.0]} mm interval, respectively. DBT projections and reconstructions of the phantoms were simulated using two acquisition geometries of our DBT prototype. The performance of both acquisition geometries was compared using breast volume segmentations of the Perlin phantoms. Results show that breast volume estimates are improved with the introduction of posterior-anterior motion of the x-ray source in DBT acquisitions. The breast volume is overestimated in DBT, varying substantially with the acquisition geometry; segmentation errors are more evident for thicker and larger breasts. These results provide additional evidence and suggest that custom acquisition geometries can improve the performance and accuracy in DBT. Perlin phantoms help to identify limitations in acquisition geometries and to optimize the performance of the DBT prototypes.
A next generation tomosynthesis (NGT) prototype is under development to investigate alternative acquisition geometries for digital breast tomosynthesis (DBT). A positron emission tomography (PET) device will be integrated into the NGT prototype to facilitate DBT acquisition followed immediately by PET acquisition (PET-DBT). The aim of this study was to identify custom acquisition geometries that (1) improve dense/adipose tissue classification and (2) improve breast outline segmentation. Our lab’s virtual clinical trial framework (OpenVCT) was used to simulate various NGT acquisitions of anthropomorphic breast phantoms. Five custom acquisition geometries of the NGT prototype, with posteroanterior (PA) x-ray source motion ranging from 40-200 mm in 40 mm steps, were simulated for five phantoms. These acquisition geometries were compared against the simulation of a conventional DBT acquisition geometry. Signal in the reconstruction was compared against the ground truth on a voxel-by-voxel basis. The segmentation of breast from air is performed during reconstruction. Within the breast, we use a threshold-based classification of glandular tissue. The threshold was varied to produce a receiver operating characteristic (ROC) curve, representing the proportion of true fibroglandular classification as a function of the proportion of false fibroglandular classification at each threshold. The area under the ROC curve (AUC) was the figure-of-merit used to quantify adipose-glandular classification performance. Reconstructed breast volume estimation and sensitivity index (d’) were calculated for all image reconstructions. Volume overestimation is highest for conventional DBT and decreases with increasing PA source motion. AUC and d’ increase with increasing PA source motion. These results suggest that NGT can improve PET-DBT attenuation corrections over conventional DBT.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.