| 1. |
- Fieselmann, Andreas, et al.
(författare)
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Volumetric breast density measurement for personalized screening : Accuracy, reproducibility, and agreement with visual assessment
- 2018
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Ingår i: 14th International Workshop on Breast Imaging (IWBI 2018). - : SPIE. - 9781510620070 ; 10718
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Konferensbidrag (refereegranskat)abstract
- Assessment of breast density at the point of mammographic examination could lead to optimized breast cancer screening pathways. The onsite breast density information may offer guidance when to recommend supplemental imaging for women in a screening program. In this work, performance evaluation of a new software (Insight BD, Siemens Healthcare GmbH) for fast onsite quantification of volumetric breast density is presented. Accuracy of volumetric measurement is evaluated using breast tissue equivalent phantom experiments. Reproducibility of measurement results is analyzed using 8150 4-view mammography exams. Furthermore, agreement between breast density categories computed by the software with those determined visually by radiologists is examined. The results of the performance evaluation demonstrate that the software delivers accurate and reproducible measurements that agree well with the visual assessment of breast density by radiologists.
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| 2. |
- Fieselmann, Andreas, et al.
(författare)
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Volumetric breast density measurement for personalized screening : Accuracy, reproducibility, consistency, and agreement with visual assessment
- 2019
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Ingår i: Journal of Medical Imaging. - 2329-4302. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- Assessment of breast density at the point of mammographic examination could lead to optimized breast cancer screening pathways. The onsite breast density information may offer guidance of when to recommend supplemental imaging for women in a screening program. A software application (Insight BD, Siemens Healthcare GmbH) for fast onsite quantification of volumetric breast density is evaluated. The accuracy of the method is assessed using breast tissue equivalent phantom experiments resulting in a mean absolute error of 3.84%. Reproducibility of measurement results is analyzed using 8427 exams in total, comparing for each exam (if available) the densities determined from left and right views, from cranio-caudal and medio-lateral oblique views, from full-field digital mammograms (FFDM) and digital breast tomosynthesis (DBT) data and from two subsequent exams of the same breast. Pearson correlation coefficients of 0.937, 0.926, 0.950, and 0.995 are obtained. Consistency of the results is demonstrated by evaluating the dependency of the breast density on women's age. Furthermore, the agreement between breast density categories computed by the software with those determined visually by 32 radiologists is shown by an overall percentage agreement of 69.5% for FFDM and by 64.6% for DBT data. These results demonstrate that the software delivers accurate, reproducible, and consistent measurements that agree well with the visual assessment of breast density by radiologists.
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| 3. |
- Förnvik, Daniel, et al.
(författare)
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Comparison between software volumetric breast density estimates in breast tomosynthesis and digital mammography images in a large public screening cohort
- 2019
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 29:1, s. 330-336
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To compare software estimates of volumetric breast density (VBD) based on breast tomosynthesis (BT) projections to those based on digital mammography (DM) images in a large screening cohort, the Malmö Breast Tomosynthesis Screening Trial (MBTST). Methods: DM and BT images of 9909 women (enrolled 2010–2015) were retrospectively analysed with prototype software to estimate VBD. Software calculation is based on a physics model of the image acquisition process and incorporates the effect of masking in DM based on accumulated dense tissue areas. VBD (continuously and categorically) was compared between BT [central projection (mediolateral oblique view (MLO)] and two-view DM, and with radiologists’ BI-RADS density 4th ed. scores. Agreement and correlation were investigated with weighted kappa (κ), Spearman’s correlation coefficient (r), and Bland–Altman analysis. Results: There was a high correlation (r = 0.83) between VBD in DM and BT and substantial agreement between the software breast density categories [observed agreement, 61.3% and 84.8%; κ = 0.61 and ĸ = 0.69 for four (a/b/c/d) and two (fat involuted vs. dense) density categories, respectively]. There was moderate agreement between radiologists’ BI-RADS scores and software density categories in DM (ĸ = 0.55) and BT (ĸ = 0.47). Conclusions: In a large public screening setting, we report a substantial agreement between VBD in DM and BT using software with special focus on masking effect. This automated and objective mode of measuring VBD may be of value to radiologists and women when BT is used as the primary breast cancer screening modality. Key Points: • There was a high correlation between continuous volumetric breast density in DM and BT.• There was substantial agreement between software breast density categories (four groups) in DM and BT; with clinically warranted binary software breast density categories, the agreement increased markedly.• There was moderate agreement between radiologists’ BI-RADS scores and software breast density categories in DM and BT.
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| 4. |
- Förnvik, Hannie, et al.
(författare)
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Towards determination of individual glandular dose
- 2018
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Ingår i: Medical Imaging 2018 : Physics of Medical Imaging - Physics of Medical Imaging. - : SPIE. - 9781510616356 ; 10573
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Konferensbidrag (refereegranskat)abstract
- Due to variations in amount and distribution of glandular breast tissue among women, the mean glandular dose (MGD) can be a poor measure of the individual glandular dose. Therefore, to improve the basis for risk assessment related to radiation dose from breast X-ray examinations, the distribution should be considered. Breast tomosynthesis (BT) is an imaging technique that may be used as an alternative or complement to standard mammography in breast cancer screening, and it could provide the required 3D-localisation of glandular tissue for estimation of the individual glandular dose. In this study, we investigated the possibility to localize glandular tissue from BT data and use a Monte Carlo simulation routine to estimate the glandular dose for software breast phantoms with different amount and distribution of glandular breast tissue. As an initial evaluation of the method, the local energy absorption in glandular tissue was estimated for seven breast phantoms and the corresponding phantoms recreated from reconstructed BT data. As expected, the normalized glandular dose was found to differ substantially with glandular distribution. This emphasizes the importance of glandular tissue localization for estimation of the individual glandular dose. The results showed good accuracy for estimation of normalized glandular dose using breast phantoms recreated from reconstructed BT image volumes (relative differences between -7.3% and +9.5%). Following this initial study, the method will be evaluated for more phantoms and potentially developed for patient cases. In the future it could become a useful tool in breast dosimetry as a step towards the individual glandular dose.
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| 5. |
- Sartor, Hanna, et al.
(författare)
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Changes in breast density over serial mammograms : A case-control study
- 2020
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Ingår i: European Journal of Radiology. - : Elsevier BV. - 0720-048X. ; 127
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: In addition to a breast density category, temporal changes in breast density have gained attention as a dynamic breast cancer risk marker. This case-control study aimed to investigate a potential change in breast density preceding tumor development and the relationship of this potential change to prognostic pathological tumor variables. Method: A total of 51 consecutive, eligible-for-analyses, biopsy-proven breast cancers were diagnosed between 1 st of August and 31 st of December 2014 at Skåne University Hospital, Sweden. Mammogram data and patient- and tumor characteristics were retrieved retrospectively from medical charts. Breast density was quantitatively estimated using LIBRA (a free open source software package). The cases were matched for year of birth, number of screening rounds, and date for first and last mammograms with controls from the Malmö Breast Tomosynthesis Screening Trial in a 1:2 ratio, resulting in median time between mammograms of 4.5 (1.3–11.9) years for cases and 4.7 (1.4–11.1) years for controls, averaging approximately three screening rounds (1–6 rounds). Results: We detected a statistically significant difference in breast density change over time, with cases showing an increase in breast density (1.7 %) as compared to controls (-0.3 %) (p = 0.045). We found that in women with breast cancer, older women (≥ 55 years) experienced a higher breast density increase compared to younger women (5.1 % vs. 0.3 %, p = 0.002). Conclusions: There was a statistically significant difference in density change, where women with breast cancer showed an increased density over time, which was particularly evident in women > 55 years of age.
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| 7. |
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| 8. |
- Bakic, Predrag R., et al.
(författare)
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Artifact reduction in simultaneous tomosynthesis and mechanical imaging of the breast
- 2019
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Ingår i: Medical Imaging 2019 : Physics of Medical Imaging - Physics of Medical Imaging. - : SPIE. - 9781510625433 ; 10948
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Konferensbidrag (refereegranskat)abstract
- Mechanical imaging (MI) uses a pressure sensor array to estimate the stiffness of lesions. Recent clinical studies have suggested that MI combined with digital mammography may reduce false positive findings and negative biopsies by over 30%. Digital breast tomosynthesis (DBT) has been adopted progressively in cancer screening. The tomographic nature of DBT improves lesion visibility by reducing tissue overlap in reconstructed images. For maximum benefit, DBT and MI data should be acquired simultaneously; however, that arrangement produces visible artifacts in DBT images due to the presence of the MI sensor array. We propose a method for reducing artifacts during the DBT image reconstruction. We modified the parameters of a commercial DBT reconstruction engine and investigated the conspicuity of artifacts in the resultant images produced with different sensor orientations. The method was evaluated using a physical anthropomorphic phantom imaged on top of the sensor. Visual assessment showed a reduction of artifacts. In a quantitative test, we calculated the artifact spread function (ASF), and compared the ratio of the mean ASF values between the proposed and conventional reconstruction (termed ASF ratio, RASF). We obtained a mean RASF of 2.74, averaged between two analyzed sensor orientations (45° and 90°). The performance varied with the orientation and the type of sensor structures causing the artifacts. RASF for wide connection lines was larger at 45° than at 90° (5.15 vs. 1.00, respectively), while for metallic contacts RASF was larger at 90° than at 45° (3.31 vs. 2.21, respectively). Future work will include a detailed quantitative assessment, and further method optimization in virtual clinical trials.
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| 9. |
- Dahlblom, Victor, et al.
(författare)
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Malmö Breast ImaginG database: objectives and development
- 2023
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Ingår i: Journal of Medical Imaging. - 2329-4302. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- PurposeWe describe the design and implementation of the Malmö Breast ImaginG (M-BIG) database, which will support research projects investigating various aspects of current and future breast cancer screening programs. Specifically, M-BIG will provide clinical data to: 1. investigate the effect of breast cancer screening on breast cancer prognosis and mortality; 2. develop and validate the use of artificial intelligence and machine learning in breast image interpretation; and 3. develop and validate image-based radiological breast cancer risk profiles.ApproachThe M-BIG database is intended to include a wide range of digital mammography (DM) and digital breast tomosynthesis (DBT) examinations performed on women at the Mammography Clinic in Malmö, Sweden, from the introduction of DM in 2004 through 2020. Subjects may be included multiple times and for diverse reasons. The image data are linked to extensive clinical, diagnostic, and demographic data from several registries.ResultsTo date, the database contains a total of 451,054 examinations from 104,791 women. During the inclusion period, 95,258 unique women were screened. A total of 19,968 examinations were performed using DBT, whereas the rest used DM.ConclusionsWe describe the design and implementation of the M-BIG database as a representative and accessible medical image database linked to various types of medical data. Work is ongoing to add features and curate the existing data.
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| 10. |
- Dalene Skarping, Ida, et al.
(författare)
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Neoadjuvant breast cancer treatment response; tumor size evaluation through different conventional imaging modalities in the NeoDense study
- 2020
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Ingår i: Acta Oncologica. - 1651-226X. ; 59:12, s. 1528-1537
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Tidskriftsartikel (refereegranskat)abstract
- Neoadjuvant chemotherapy (NACT) is offered to an increasing number of breast cancer (BC) patients, and comprehensive monitoring of treatment response is of utmost importance. Several imaging modalities are available to follow tumor response, although likely to provide different clinical information. We aimed to examine the association between early radiological response by three conventional imaging modalities and pathological complete response (pCR). Further, we investigated the agreement between these modalities pre-, during, and post-NACT, and the accuracy of predicting pathological residual tumor burden by these imaging modalities post-NACT.
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