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Vedantham S. Contrast-enhanced breast computed tomography: can lymph node metastasis be predicted from primary tumor? Eur Radiol 2024; 34:2574-2575. [PMID: 37930415 DOI: 10.1007/s00330-023-10399-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 09/29/2023] [Accepted: 10/14/2023] [Indexed: 11/07/2023]
Affiliation(s)
- Srinivasan Vedantham
- Department of Medical Imaging, The University of Arizona, 1501 N Campbell Avenue, Tucson, AZ, 85724, USA.
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Tseng HW, Karellas A, Vedantham S. Cone-beam breast CT using an offset detector: effect of detector offset and image reconstruction algorithm. Phys Med Biol 2022; 67. [PMID: 35316793 PMCID: PMC9045275 DOI: 10.1088/1361-6560/ac5fe1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/22/2022] [Indexed: 11/12/2022]
Abstract
Objective.A dedicated cone-beam breast computed tomography (BCT) using a high-resolution, low-noise detector operating in offset-detector geometry has been developed. This study investigates the effects of varying detector offsets and image reconstruction algorithms to determine the appropriate combination of detector offset and reconstruction algorithm.Approach.Projection datasets (300 projections in 360°) of 30 breasts containing calcified lesions that were acquired using a prototype cone-beam BCT system comprising a 40 × 30 cm flat-panel detector with 1024 × 768 detector pixels were reconstructed using Feldkamp-Davis-Kress (FDK) algorithm and served as the reference. The projection datasets were retrospectively truncated to emulate cone-beam datasets with sinograms of 768×768 and 640×768 detector pixels, corresponding to 5 cm and 7.5 cm lateral offsets, respectively. These datasets were reconstructed using the FDK algorithm with appropriate weights and an ASD-POCS-based Fast, total variation-Regularized, Iterative, Statistical reconstruction Technique (FRIST), resulting in a total of 4 offset-detector reconstructions (2 detector offsets × 2 reconstruction methods). Signal difference-to-noise ratio (SDNR), variance, and full-width at half-maximum (FWHM) of calcifications in two orthogonal directions were determined from all reconstructions. All quantitative measurements were performed on images in units of linear attenuation coefficient (1/cm).Results.The FWHM of calcifications did not differ (P > 0.262) among reconstruction algorithms and detector formats, implying comparable spatial resolution. For a chosen detector offset, the FRIST algorithm outperformed FDK in terms of variance and SDNR (P < 0.0001). For a given reconstruction method, the 5 cm offset provided better results.Significance.This study indicates the feasibility of using the compressed sensing-based, FRIST algorithm to reconstruct sinograms from offset-detectors. Among the reconstruction methods and detector offsets studied, FRIST reconstructions corresponding to a 30 cm × 30 cm with 5 cm lateral offset, achieved the best performance. A clinical prototype using such an offset geometry has been developed and installed for clinical trials.
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Affiliation(s)
- Hsin Wu Tseng
- Department of Medical Imaging, The University of Arizona, Tucson, AZ, United States of America
| | - Andrew Karellas
- Department of Medical Imaging, The University of Arizona, Tucson, AZ, United States of America
| | - Srinivasan Vedantham
- Department of Medical Imaging, The University of Arizona, Tucson, AZ, United States of America.,Department of Biomedical Engineering, The University of Arizona, Tucson, AZ, United States of America
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Vedantham S, Karellas A. Breast Cancer Screening: Opportunities and Challenges with Fully 3D Tomographic X-Ray Imaging. BRIDGE (WASHINGTON, D.C. : 1969) 2022; 52:33-42. [PMID: 35431425 PMCID: PMC9012464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Affiliation(s)
- Srinivasan Vedantham
- Departments of Medical Imaging and Biomedical Engineering, University of Arizona
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Dedicated breast CT: state of the art-Part I. Historical evolution and technical aspects. Eur Radiol 2021; 32:1579-1589. [PMID: 34342694 DOI: 10.1007/s00330-021-08179-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/19/2021] [Accepted: 06/29/2021] [Indexed: 12/24/2022]
Abstract
Dedicated breast CT is an emerging 3D isotropic imaging technology for breast, which overcomes the limitations of 2D compression mammography and limited angle tomosynthesis while providing some of the advantages of magnetic resonance imaging. This first installment in a 2-part review describes the evolution of dedicated breast CT beginning with a historical perspective and progressing to the present day. Moreover, it provides an overview of state-of-the-art technology. Particular emphasis is placed on technical limitations in scan protocol, radiation dose, breast coverage, patient comfort, and image artifact. Proposed methods of how to address these technical challenges are also discussed. KEY POINTS: • Advantages of breast CT include no tissue overlap, improved patient comfort, rapid acquisition, and concurrent assessment of microcalcifications and contrast enhancement. • Current clinical and prototype dedicated breast CT systems differ in acquisition modes, imaging techniques, and detector types. • There are still details to be decided regarding breast CT techniques, such as scan protocol, radiation dose, breast coverage, patient comfort, and image artifact.
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Tseng HW, Karellas A, Vedantham S. Radiation dosimetry of a clinical prototype dedicated cone-beam breast CT system with offset detector. Med Phys 2021; 48:1079-1088. [PMID: 33501686 DOI: 10.1002/mp.14688] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 12/27/2022] Open
Abstract
PURPOSE A clinical-prototype, dedicated, cone-beam breast computed tomography (CBBCT) system with offset detector is undergoing clinical evaluation at our institution. This study is to estimate the normalized glandular dose coefficients ( DgN CT ) that provide air kerma-to-mean glandular dose conversion factors using Monte Carlo simulations. MATERIALS AND METHODS The clinical prototype CBBCT system uses 49 kV x-ray spectrum with 1.39 mm 1st half-value layer thickness. Monte Carlo simulations (GATE, version 8) were performed with semi-ellipsoidal, homogeneous breasts of various fibroglandular weight fractions ( f g = 0.01 , 0.15 , 0.5 , 1 ) , chest wall diameters ( d = 8 , 10 , 14 , 18 , 20 cm), and chest wall to nipple length ( l = 0.75 d ), aligned with the axis of rotation (AOR) located at 65 cm from the focal spot to determine the DgN CT . Three geometries were considered - 40 × 30 -cm detector with no offset that served as reference and corresponds to a clinical CBBCT system, 30 × 30 -cm detector with 5 cm offset, and a 30 × 30 -cm detector with 10 cm offset. RESULTS For 5 cm lateral offset, the DgN CT ranged 0.177 - 0.574 mGy/mGy and reduction in DgN CT with respect to reference geometry was observed only for 18 cm ( 6.4 % ± 0.23 % ) and 20 cm ( 9.6 % ± 0.22 % ) diameter breasts. For the 10 cm lateral offset, the DgN CT ranged 0.221 - 0.581 mGy/mGy and reduction in DgN CT was observed for all breast diameters. The reduction in DgN CT was 1.4 % ± 0.48 % , 7.1 % ± 0.13 % , 17.5 % ± 0.19 % , 25.1 % ± 0.15 % , and 27.7 % ± 0.08 % for 8, 10, 14, 18, and 20 cm diameter breasts, respectively. For a given breast diameter, the reduction in DgN CT with offset-detector geometries was not dependent on f g . Numerical fits of DgN CT d , l , f g were generated for each geometry. CONCLUSION The DgN CT and the numerical fit, D g N CT d , l , f g would be of benefit for current CBBCT systems using the reference geometry and for future generations using offset-detector geometry. There exists a potential for radiation dose reduction with offset-detector geometry, provided the same technique factors as the reference geometry are used, and the image quality is clinically acceptable.
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Affiliation(s)
- Hsin Wu Tseng
- Department of Medical Imaging, The University of Arizona, Tucson, AZ, USA
| | - Andrew Karellas
- Department of Medical Imaging, The University of Arizona, Tucson, AZ, USA
| | - Srinivasan Vedantham
- Department of Medical Imaging, The University of Arizona, Tucson, AZ, USA.,Department of Biomedical Engineering, The University of Arizona, Tucson, AZ, USA
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Tseng HW, Karellas A, Vedantham S. Optical conductivity of triple point fermions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:10.1088/2057-1976/abb834. [PMID: 33373981 PMCID: PMC8004539 DOI: 10.1088/1361-648x/abd739] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/29/2020] [Indexed: 01/12/2023]
Abstract
As a low-energy effective theory on non-symmorphic lattices, we consider a generic triple point fermion Hamiltonian, which is parameterized by an angular parameterλ. We find strongλdependence in both Drude and interband optical absorption of these systems. The deviation of theT2coefficient of the Drude weight from Dirac/Weyl fermions can be used as a quick way to optically distinguish the triple point degeneracies from the Dirac/Weyl degeneracies. At the particularλ=π/6 point, we find that the 'helicity' reversal optical transition matrix element is identically zero. Nevertheless, deviating from this point, the helicity reversal emerges as an absorption channel.
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Affiliation(s)
- Hsin Wu Tseng
- Department of Medical Imaging, The University of Arizona, Tucson, AZ
| | - Andrew Karellas
- Department of Medical Imaging, The University of Arizona, Tucson, AZ
| | - Srinivasan Vedantham
- Department of Medical Imaging, The University of Arizona, Tucson, AZ
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ
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Tseng HW, Karellas A, Vedantham S. Sparse-view, short-scan, dedicated cone-beam breast computed tomography: image quality assessment. Biomed Phys Eng Express 2020; 6:10.1088/2057-1976/abb834. [PMID: 33377758 PMCID: PMC8004539 DOI: 10.1088/2057-1976/abb834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/14/2020] [Indexed: 01/01/2023]
Abstract
The purpose of this study is to quantify the impact of sparse-view acquisition in short-scan trajectories, compared to 360-degrees full-scan acquisition, on image quality measures in dedicated cone-beam breast computed tomography (BCT). Projection data from 30 full-scan (360-degrees; 300 views) BCT exams with calcified lesions were selected from an existing clinical research database. Feldkamp-Davis-Kress (FDK) reconstruction of the full-scan data served as the reference. Projection data corresponding to two short-scan trajectories, 204 and 270-degrees, which correspond to the minimum and maximum angular range achievable in a cone-beam BCT system were selected. Projection data were retrospectively sampled to provide 225, 180, and 168 views for 270-degrees short-scan, and 170 views for 204-degrees short-scan. Short-scans with 180 and 168 views in 270-degrees used non-uniform angular sampling. A fast, iterative, total variation-regularized, statistical reconstruction technique (FIRST) was used for short-scan image reconstruction. Image quality was quantified by variance, signal-difference to noise ratio (SDNR) between adipose and fibroglandular tissues, full-width at half-maximum (FWHM) of calcifications in two orthogonal directions, as well as, bias and root-mean-squared-error (RMSE) computed with respect to the reference full-scan FDK reconstruction. The median values of bias (8.6 × 10-4-10.3 × 10-4cm-1) and RMSE (6.8 × 10-6-9.8 × 10-6cm-1) in the short-scan reconstructions, computed with the full-scan FDK as the reference were close to, but not zero (P < 0.0001, one-sample median test). The FWHM of the calcifications in the short-scan reconstructions did not differ significantly from the reference FDK reconstruction (P > 0.118), except along the superior-inferior direction for the short-scan reconstruction with 168 views in 270-degrees (P = 0.046). The variance and SDNR from short-scan reconstructions were significantly improved compared to the full-scan FDK reconstruction (P < 0.0001). This study demonstrates the feasibility of the short-scan, sparse-view, compressed sensing-based iterative reconstruction. This study indicates that shorter scan times and reduced radiation dose without sacrificing image quality are potentially feasible.
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Affiliation(s)
- Hsin Wu Tseng
- Department of Medical Imaging, The University of Arizona, Tucson, AZ
| | - Andrew Karellas
- Department of Medical Imaging, The University of Arizona, Tucson, AZ
| | - Srinivasan Vedantham
- Department of Medical Imaging, The University of Arizona, Tucson, AZ
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ
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Mettivier G, Masi M, Arfelli F, Brombal L, Delogu P, Di Lillo F, Donato S, Fedon C, Golosio B, Oliva P, Rigon L, Sarno A, Taibi A, Russo P. Radiochromic film dosimetry in synchrotron radiation breast computed tomography: a phantom study. JOURNAL OF SYNCHROTRON RADIATION 2020; 27:762-771. [PMID: 32381779 PMCID: PMC7285685 DOI: 10.1107/s1600577520001745] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 02/07/2020] [Indexed: 06/11/2023]
Abstract
This study relates to the INFN project SYRMA-3D for in vivo phase-contrast breast computed tomography using the SYRMEP synchrotron radiation beamline at the ELETTRA facility in Trieste, Italy. This peculiar imaging technique uses a novel dosimetric approach with respect to the standard clinical procedure. In this study, optimization of the acquisition procedure was evaluated in terms of dose delivered to the breast. An offline dose monitoring method was also investigated using radiochromic film dosimetry. Various irradiation geometries have been investigated for scanning the prone patient's pendant breast, simulated by a 14 cm-diameter polymethylmethacrylate cylindrical phantom containing pieces of calibrated radiochromic film type XR-QA2. Films were inserted mid-plane in the phantom, as well as wrapped around its external surface, and irradiated at 38 keV, with an air kerma value that would produce an estimated mean glandular dose of 5 mGy for a 14 cm-diameter 50% glandular breast. Axial scans were performed over a full rotation or over 180°. The results point out that a scheme adopting a stepped rotation irradiation represents the best geometry to optimize the dose distribution to the breast. The feasibility of using a piece of calibrated radiochromic film wrapped around a suitable holder around the breast to monitor the scan dose offline is demonstrated.
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Affiliation(s)
- Giovanni Mettivier
- Dipartimento di Fisica ‘Ettore Pancini’, Università di Napoli ‘Federico II’, I-80126 Napoli, Italy
- INFN, Sezione di Napoli, I-80126 Napoli, Italy
| | - Marica Masi
- Dipartimento di Fisica ‘Ettore Pancini’, Università di Napoli ‘Federico II’, I-80126 Napoli, Italy
- INFN, Sezione di Napoli, I-80126 Napoli, Italy
| | - Fulvia Arfelli
- Department of Physics, Università di Trieste, I-34127 Trieste, Italy
- Sezione di Trieste, INFN, I-34127 Trieste, Italy
| | - Luca Brombal
- Department of Physics, Università di Trieste, I-34127 Trieste, Italy
- Sezione di Trieste, INFN, I-34127 Trieste, Italy
| | - Pasquale Delogu
- Department of Physical Science, Earth and Environment, Università di Siena, I-53100 Siena, Italy
- Sezione di Pisa, INFN, I-34127 Pisa, Italy
| | - Francesca Di Lillo
- Dipartimento di Fisica ‘Ettore Pancini’, Università di Napoli ‘Federico II’, I-80126 Napoli, Italy
- INFN, Sezione di Napoli, I-80126 Napoli, Italy
- ELETTRA-Sincrotrone Trieste SCpA, Bassovizza, I-34149 Trieste, Italy
| | - Sandro Donato
- Department of Physics, Università di Trieste, I-34127 Trieste, Italy
- Sezione di Trieste, INFN, I-34127 Trieste, Italy
| | - Christian Fedon
- Sezione di Trieste, INFN, I-34127 Trieste, Italy
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Bruno Golosio
- Department of Physics, Università di Cagliari, I-09042 Cagliari, Italy
- Sezione di Cagliari, INFN, I-09042 Cagliari, Italy
| | - Piernicola Oliva
- Sezione di Cagliari, INFN, I-09042 Cagliari, Italy
- Department of Chemistry and Pharmacy, Università di Sassari, Sassari, Italy
| | - Luigi Rigon
- Department of Physics, Università di Trieste, I-34127 Trieste, Italy
- Sezione di Trieste, INFN, I-34127 Trieste, Italy
| | | | - Angelo Taibi
- Department of Physics and Earth Science, Università di Ferrara, I-44122 Ferrara, Italy
- Sezione di Ferrara, INFN, I-44122 Ferrara, Italy
| | - Paolo Russo
- Dipartimento di Fisica ‘Ettore Pancini’, Università di Napoli ‘Federico II’, I-80126 Napoli, Italy
- INFN, Sezione di Napoli, I-80126 Napoli, Italy
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Vedantham S, Tseng HW, Konate S, Shi L, Karellas A. Dedicated cone-beam breast CT using laterally-shifted detector geometry: Quantitative analysis of feasibility for clinical translation. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2020; 28:405-426. [PMID: 32333575 PMCID: PMC7347391 DOI: 10.3233/xst-200651] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
BACKGROUND High-resolution, low-noise detectors with minimal dead-space at chest-wall could improve posterior coverage and microcalcification visibility in the dedicated cone-beam breast CT (CBBCT). However, the smaller field-of-view necessitates laterally-shifted detector geometry to enable optimizing the air-gap for x-ray scatter rejection. OBJECTIVE To evaluate laterally-shifted detector geometry for CBBCT with clinical projection datasets that provide for anatomical structures and lesions. METHODS CBBCT projection datasets (n = 17 breasts) acquired with a 40×30 cm detector (1024×768-pixels, 0.388-mm pixels) were truncated along the fan-angle to emulate 20.3×30 cm, 22.2×30 cm and 24.1×30 cm detector formats and correspond to 20, 120, 220 pixels overlap in conjugate views, respectively. Feldkamp-Davis-Kress (FDK) algorithm with 3 different weighting schemes were used for reconstruction. Visual analysis for artifacts and quantitative analysis of root-mean-squared-error (RMSE), absolute difference between truncated and 40×30 cm reconstructions (Diff), and its power spectrum (PSDiff) were performed. RESULTS Artifacts were observed for 20.3×30 cm, but not for other formats. The 24.1×30 cm provided the best quantitative results with RMSE and Diff (both in units of μ, cm-1) of 4.39×10-3±1.98×10-3 and 4.95×10-4±1.34×10-4, respectively. The PSDiff (>0.3 cycles/mm) was in the order of 10-14μ2mm3 and was spatial-frequency independent. CONCLUSIONS Laterally-shifted detector CBBCT with at least 220 pixels overlap in conjugate views (24.1×30 cm detector format) provides quantitatively accurate and artifact-free image reconstruction.
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Affiliation(s)
- Srinivasan Vedantham
- Department of Medical Imaging, University of Arizona, Tucson, AZ 85724
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85724
| | - Hsin-Wu Tseng
- Department of Medical Imaging, University of Arizona, Tucson, AZ 85724
| | - Souleymane Konate
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA 02115
| | - Linxi Shi
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Andrew Karellas
- Department of Medical Imaging, University of Arizona, Tucson, AZ 85724
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Guo R, Lu G, Qin B, Fei B. Ultrasound Imaging Technologies for Breast Cancer Detection and Management: A Review. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:37-70. [PMID: 29107353 PMCID: PMC6169997 DOI: 10.1016/j.ultrasmedbio.2017.09.012] [Citation(s) in RCA: 195] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 05/25/2023]
Abstract
Ultrasound imaging is a commonly used modality for breast cancer detection and diagnosis. In this review, we summarize ultrasound imaging technologies and their clinical applications for the management of breast cancer patients. The technologies include ultrasound elastography, contrast-enhanced ultrasound, 3-D ultrasound, automatic breast ultrasound and computer-aided detection of breast ultrasound. We summarize the study results seen in the literature and discuss their future directions. We also provide a review of ultrasound-guided, breast biopsy and the fusion of ultrasound with other imaging modalities, especially magnetic resonance imaging (MRI). For comparison, we also discuss the diagnostic performance of mammography, MRI, positron emission tomography and computed tomography for breast cancer diagnosis at the end of this review. New ultrasound imaging techniques, ultrasound-guided biopsy and the fusion of ultrasound with other modalities provide important tools for the management of breast patients.
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Affiliation(s)
- Rongrong Guo
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia, USA; Department of Ultrasound, Shanxi Provincial Cancer Hospital, Taiyuan, Shanxi, China
| | - Guolan Lu
- The Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Binjie Qin
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Baowei Fei
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia, USA; The Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia, USA; Department of Mathematics and Computer Science, Emory College of Emory University, Atlanta, Georgia, USA; Winship Cancer Institute of Emory University, Atlanta, Georgia, USA.
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Jeon H, Youn H, Kim JS, Nam J, Lee J, Lee J, Park D, Kim W, Ki Y, Kim D. Generation of polychromatic projection for dedicated breast computed tomography simulation using anthropomorphic numerical phantom. PLoS One 2017; 12:e0187242. [PMID: 29108024 PMCID: PMC5673211 DOI: 10.1371/journal.pone.0187242] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 10/17/2017] [Indexed: 11/21/2022] Open
Abstract
Numerical simulations are fundamental to the development of medical imaging systems because they can save time and effort in research and development. In this study, we developed a method of creating the virtual projection images that are necessary to study dedicated breast computed tomography (BCT) systems. Anthropomorphic software breast phantoms of the conventional compression type were synthesized and redesigned to meet the requirements of dedicated BCT systems. The internal structure of the breast was randomly constructed to develop the proposed phantom, enabling the internal structure of a naturally distributed real breast to be simulated. When using the existing monochromatic photon incidence assumption for projection-image generation, it is not possible to simulate various artifacts caused by the X-ray spectrum, such as the beam hardening effect. Consequently, the system performance could be overestimated. Therefore, we considered the polychromatic spectrum in the projection image generation process and verified the results. The proposed method is expected to be useful for the development and optimization of BCT systems.
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Affiliation(s)
- Hosang Jeon
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Hanbean Youn
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Jin Sung Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Jiho Nam
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Jayoung Lee
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Juhye Lee
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Dahl Park
- Department of Radiation Oncology, Pusan National University Hospital, Busan, South Korea
| | - Wontaek Kim
- Department of Radiation Oncology, Pusan National University Hospital, Busan, South Korea
| | - Yongkan Ki
- Department of Radiation Oncology, Pusan National University Hospital, Busan, South Korea
| | - Donghyun Kim
- Department of Radiation Oncology, Pusan National University Hospital, Busan, South Korea
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O'Connell AM, Karellas A, Vedantham S, Kawakyu-O'Connor DT. Newer Technologies in Breast Cancer Imaging: Dedicated Cone-Beam Breast Computed Tomography. Semin Ultrasound CT MR 2017; 39:106-113. [PMID: 29317032 DOI: 10.1053/j.sult.2017.09.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Dedicated breast computed tomography (CT) is the latest in a long history of breast imaging techniques dating back to the 1960s. Breast imaging is performed both for cancer screening as well as for diagnostic evaluation of symptomatic patients. Dedicated breast CT received US Food and Drug Administration approval for diagnostic use in 2015 and is slowly gaining recognition for its value in diagnostic 3-dimensional imaging of the breast, and also for injected contrast-enhanced imaging applications. Conventional mammography has known limitations in sensitivity and specificity, especially in dense breasts. Breast tomosynthesis was US Food and Drug Administration approved in 2011 and is now widely used. Dedicated breast CT is the next technological advance, combining real 3-dimensional imaging with the ease of contrast administration. The lack of painful compression and manipulation of the breasts also makes dedicated breast CT much more acceptable for the patients.
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Affiliation(s)
- Avice M O'Connell
- Department of Imaging Sciences, Section of Women's Imaging, University of Rochester Medical Center, Rochester, NY
| | - Andrew Karellas
- Department of Medical Imaging, Banner University Medical Center, University of Arizona College of Medicine, Tucson, AZ
| | - Srinivasan Vedantham
- Department of Medical Imaging (DMI), Office for Project Statistical and Design Support-DMI, Banner University Medical Center, University of Arizona College of Medicine, Tucson, AZ
| | - Daniel T Kawakyu-O'Connor
- Department of Imaging Sciences, Section of Emergency Imaging, University of Rochester Medical Center, Rochester, NY.
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Xu J, Sisniega A, Zbijewski W, Dang H, Stayman JW, Wang X, Foos DH, Aygun N, Koliatsos VE, Siewerdsen JH. Modeling and design of a cone-beam CT head scanner using task-based imaging performance optimization. Phys Med Biol 2016; 61:3180-207. [DOI: 10.1088/0031-9155/61/8/3180] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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O'Connell AM, Karellas A, Vedantham S. The potential role of dedicated 3D breast CT as a diagnostic tool: review and early clinical examples. Breast J 2014; 20:592-605. [PMID: 25199995 DOI: 10.1111/tbj.12327] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mammography is the gold standard in routine screening for the detection of breast cancer in the general population. However, limitations in sensitivity, particularly in dense breasts, has motivated the development of alternative imaging techniques such as digital breast tomosynthesis, whole breast ultrasound, breast-specific gamma imaging, and more recently dedicated breast computed tomography or "breast CT". Virtually all diagnostic work-ups of asymptomatic nonpalpable findings arise from screening mammography. In most cases, diagnostic mammography and ultrasound are sufficient for diagnosis, with magnetic resonance imaging (MRI) playing an occasional role. Digital breast tomosynthesis, a limited-angle tomographic technique, is increasingly being used for screening. Dedicated breast CT has full three-dimensional (3D) capability with near-isotropic resolution, which could potentially improve diagnostic accuracy. In current dedicated breast CT clinical prototypes, 300-500 low-dose projections are acquired in a circular trajectory around the breast using a flat panel detector, followed by image reconstruction to provide the 3D breast volume. The average glandular dose to the breast from breast CT can range from as little as a two-view screening mammogram to approximately that of a diagnostic mammography examination. Breast CT displays 3D images of the internal structures of the breast; therefore, evaluation of suspicious features like microcalcifications, masses, and asymmetries can be made in multiple anatomical planes from a single scan. The potential role of breast CT for diagnostic imaging is illustrated here through clinical examples such as imaging soft tissue abnormalities and microcalcifications. The potential for breast CT to serve as an imaging tool for extent of disease evaluation and for monitoring neo-adjuvant chemotherapy response is also illustrated.
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Affiliation(s)
- Avice M O'Connell
- Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York
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Vedantham S, Shi L, Karellas A, O'Connell AM, Conover DL. Personalized estimates of radiation dose from dedicated breast CT in a diagnostic population and comparison with diagnostic mammography. Phys Med Biol 2013; 58:7921-36. [PMID: 24165162 DOI: 10.1088/0031-9155/58/22/7921] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study retrospectively analyzed the mean glandular dose (MGD) to 133 breasts from 132 subjects, all women, who participated in a clinical trial evaluating dedicated breast CT in a diagnostic population. The clinical trial was conducted in adherence to a protocol approved by institutional review boards and the study participants provided written informed consent. Individual estimates of MGD to each breast from dedicated breast CT was obtained by combining x-ray beam characteristics with estimates of breast dimensions and fibroglandular fraction from volumetric breast CT images, and using normalized glandular dose coefficients. For each study participant and for the breast corresponding to that imaged with breast CT, an estimate of the MGD from diagnostic mammography (including supplemental views) was obtained from the DICOM image headers for comparison. This estimate uses normalized glandular dose coefficients corresponding to a breast with 50% fibroglandular weight fraction. The median fibroglandular weight fraction for the study cohort determined from volumetric breast CT images was 15%. Hence, the MGD from diagnostic mammography was corrected to be representative of the study cohort. Individualized estimates of MGD from breast CT ranged from 5.7 to 27.8 mGy. Corresponding to the breasts imaged with breast CT, the MGD from diagnostic mammography ranged from 2.6 to 31.6 mGy. The mean (± inter-breast SD) and the median MGD (mGy) from dedicated breast CT exam were 13.9 ± 4.6 and 12.6, respectively. For the corresponding breasts, the mean (± inter-breast SD) and the median MGD (mGy) from diagnostic mammography were 12.4 ± 6.3 and 11.1, respectively. Statistical analysis indicated that at the 0.05 level, the distributions of MGD from dedicated breast CT and diagnostic mammography were significantly different (Wilcoxon signed ranks test, p = 0.007). While the interquartile range and the range (maximum-minimum) of MGD from dedicated breast CT was lower than diagnostic mammography, the median MGD from dedicated breast CT was approximately 13.5% higher than that from diagnostic mammography. The MGD for breast CT is based on a 1.45 mm skin layer and that for diagnostic mammography is based on a 4 mm skin layer; thus, favoring a lower estimate for MGD from diagnostic mammography. The median MGD from dedicated breast CT corresponds to the median MGD from four to five diagnostic mammography views. In comparison, for the same 133 breasts, the mean and the median number of views per breast during diagnostic mammography were 4.53 and 4, respectively. Paired analysis showed that there was approximately equal likelihood of receiving lower MGD from either breast CT or diagnostic mammography. Future work will investigate methods to reduce and optimize radiation dose from dedicated breast CT.
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Affiliation(s)
- Srinivasan Vedantham
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
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