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1.
Chinese Journal of Radiological Medicine and Protection ; (12): 475-482, 2023.
Article in Chinese | WPRIM | ID: wpr-993115

ABSTRACT

Objective:To compare radiation dose between digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM), and explore the correlation of average glandular dose(AGD) with breast density and compression thickness.Methods:The mammographic data of patients with breast diseases who underwent digital breast tomosynthesis (DBT) and the population who underwent full-field digital mammography (FFDM) screening in the First Affiliated Hospital of Kunming Medical University from October 2020 to May 2022 were retrospectively collected. The compression thickness, compression force and AGD were recorded. According to the 2013 ACR BI-RADS MAMMOGRAPHY, the breast gland density was classified into 4 types: a(glandular tissue<25%), b(glandular tissue 25%~50%), c(glandular tissue 50%~75%) and d(glandular tissue >75%), by two senior doctors engaged in breast imaging diagnosis. The relationships between different gland densities, different compression thicknesses and AGD under FFDM and DBT mode were analyzed.Results:In both FFDM and DBT modes, the AGD increased significantly with the increase of breast density( F=861.63, 617.83, 330.33, 451.45, 290.47, P<0.001), and AGD a<AGD b<AGD c<AGD d. For type c and d breasts undergoing FFDM, AGD was lowest when the compression thickness was 31~40 mm. Under the same compression thickness, The AGD DBT was significantly higher than the AGD FFDMin all types (Type a: t=-17.88, -42.19, -29.90, -28.14, -24.95, P<0.001; Type b: t=-49.18, -35.94, -27.25, -28.37, -24.10, P<0.001; Type c: t=-11.78, -32.90, -23.13, -20.51, -18.24, P<0.001; Type d: t=-7.94, -26.24, -17.24, -15.44, -13.81, P<0.001). The difference between two AGDs of Type d with compression thickness of 61~70 mm was the largest, which was 1.07 mGy (95% CI: 0.92~1.22). The AGD was positively correlated with breast density and compression thickness, and the relationship of FFDM was stronger than that of DBT. Conclusions:The AGD is positively correlated with breast density and compression thickness in mammography. Compared with FFDM, DBT can increase AGD, The AGD would increase in DBT than FFDM but be safe. DBT would be beneficial to patients with breast diseases in clinical practice.

2.
Chinese Journal of Radiological Medicine and Protection ; (12): 645-650, 2022.
Article in Chinese | WPRIM | ID: wpr-956839

ABSTRACT

Objective:To compare and analyze the relationship between average glandular dose (AGD) and breast density and compression thickness in digital breast tomosynthesis(DBT)/full-field digital mammography(FFDM), and to explore the optimal selection and application of imaging parameters for different types of breast (thickness and density) in specific situations.Methods:The clinical data of 229 cases of breast Combo (DBT+ FFDM) were retrospectively analyzed. The compression thickness, AGD, kVp and type of quantified breast density (Q_abd) of CC and MLO view were collected respectively. The relationship between the AGD and the breast compression thickness and Q_abd density classification was analyzed.Results:There was a positive correlation between AGD and compression thickness (CC: r =0.55, 0.53, P< 0.001; MLO: r =0.62, 0.48, P< 0.001) and breast density(CC: r =0.36, 0.39, P< 0.001; MLO: r =0.16, 0.30, P < 0.001) in DBT/FFDM. The difference between groups for AGD was little in CC of DBT, but significant in CC of FFDM(groups by thickness, CC: F =35.29, 31.32, P<0.005; MLO: F =44.83, 27.02, P<0.005; groups by Q_abd, CC: F =18.68, 19.76, P<0.005, MLO: F=4.58, 10.52, P<0.005); the breast Q_abd was inversely proportion to the mean compression thickness (CC: F =16.28, P<0.005; MLO: F =17.81, P<0.005). At the same time, the interaction effect on AGD between the breast density and thickness was considered, and only for the MLO in FFDM mode they had an interaction on AGD ( F =3.16, P =0.005). Conclusions:The cumulative dose of DBT and FFDM may increase the radiation risk. Single-view CC/MLO-DBT or CC/MLO-(DBT+ FFDM)+ single-view MLO/CC-FFDM mode is preferred for mammography, which plays a positive role in radiation risk reduction.

3.
Chinese Journal of Radiology ; (12): 737-741, 2019.
Article in Chinese | WPRIM | ID: wpr-754975

ABSTRACT

Objective To assess the diagnostic performance of contrast-enhanced spectral mammography (CESM) in suspected breast lesions. Methods A total of 97 patients with suspected breast cancer identified by clinical examination or screening underwent two-views CESM examination on the basis of digital breast tomosynthesis (DBT) combined with full-field digital mammography (FFDM), and they were finally confirmed by biopsy or pathology. Three senior radiologists analyzed images, including lesion visibility, lesion characteristics, enhancement type, degree of enhancement, BIRDS classification, etc. Finally, based on the pathology, we compared the CESM+DBT+FFDM and DBT+FFDM two models according to sensitivity, specificity and ROC for diagnostic performance. Results There were a total of 120 lesions. Eighty-nine lesions were malignant, 31 benign; CESM was not enhanced in 2 cases, mild enhancement was performed in 22 cases, moderately intensive in 15 cases, highly intensive in 81 cases, and 2 cases were not enhanced; mass-enhanced in 96 cases, including ring-enhanced in 12 cases, 22 cases of non-mass type. The sensitivities of the combination of CESM and not combination of CESM were 91.0% and 80.9%, respectively, and the specificities were 93.5% and 87.1%, respectively. The area under the ROC curve of combination of CESM was higher than the without combination of CESM (0.923 and 0.900, P<0.05), The difference was statistically significant. Conclusion For suspicious lesions, CESM examination can improve the diagnosis accuracy of breast cancer.

4.
Chinese Journal of Radiology ; (12): 737-741, 2019.
Article in Chinese | WPRIM | ID: wpr-797669

ABSTRACT

Objective@#To assess the diagnostic performance of contrast-enhanced spectral mammography (CESM) in suspected breast lesions.@*Methods@#A total of 97 patients with suspected breast cancer identified by clinical examination or screening underwent two-views CESM examination on the basis of digital breast tomosynthesis (DBT) combined with full-field digital mammography (FFDM), and they were finally confirmed by biopsy or pathology. Three senior radiologists analyzed images, including lesion visibility, lesion characteristics, enhancement type, degree of enhancement, BIRDS classification, etc. Finally, based on the pathology, we compared the CESM+DBT+FFDM and DBT+FFDM two models according to sensitivity, specificity and ROC for diagnostic performance.@*Results@#There were a total of 120 lesions. Eighty-nine lesions were malignant, 31 benign; CESM was not enhanced in 2 cases, mild enhancement was performed in 22 cases, moderately intensive in 15 cases, highly intensive in 81 cases, and 2 cases were not enhanced; mass-enhanced in 96 cases, including ring-enhanced in 12 cases, 22 cases of non-mass type. The sensitivities of the combination of CESM and not combination of CESM were 91.0% and 80.9%, respectively, and the specificities were 93.5% and 87.1%, respectively. The area under the ROC curve of combination of CESM was higher than the without combination of CESM (0.923 and 0.900, P<0.05), The difference was statistically significant.@*Conclusion@#For suspicious lesions, CESM examination can improve the diagnosis accuracy of breast cancer.

5.
Acta Academiae Medicinae Sinicae ; (6): 667-672, 2019.
Article in Chinese | WPRIM | ID: wpr-775978

ABSTRACT

Objective To compare the values of dynamic enhanced magnetic resonance imaging(DCE-MRI),digital breast tomosynthesis(DBT),and digital mammography(DM)in the early detection and diagnosis of breast cancer.Methods We retrospectively analyzed the clinical and imaging data of 65 cases with early breast cancer confirmed by surgical pathology from June 2017 to December 2018.All patients underwent breast DCE-MRI,DM and DBT before surgery.The receiver operating characteristic(ROC)curves were drawn,with the pathological results as the gold standard,to evaluate the diagnostic performance of different examination methods.The areas under ROC curves(AUCs)were compared using test.The differences among DCE-MRI,DBT and DM in detecting early breast cancer were compared using chi-square test in terms of positive rates,accuracy,sensitivity,and specificity.Pearson correlation analysis was performed to assess the accuracy of these imaging methods in detecting the size of early breast cancer.Results The AUCs of DCE-MRI,DBT,and DM based on the BI-RADS classification for early diagnosis of breast cancer were 0.910,0.832,and 0.700,respectively(=2.132,=0.001);the sensitivity of DCE-MRI,DBT,and DM for early breast cancer was 92.3%,70.8%,and 52.5%,the specificity was 65.0%,85.0%,and 79.3%,and the accuracy was 83.1%,70.8%,and 50.8%,indicating that DCE-MRI(=15.330,=0.0001) and DBT(=5.450,=0.020) had significantly higher diagnostic accuracy than DM.The measurement results of DM,DBT,and DCE-MRI were positively correlated with the pathological measurements(=0.781,=0.847,=0.946;all <0.01). Conclusions DCE-MRI and DBT have higher positive rates and accuracies than DM in detecting early breast cancer.Medical institutions where DCE-MRI is still not available can use DBT to improve the early detection of breast cancer.


Subject(s)
Female , Humans , Breast , Diagnostic Imaging , Breast Neoplasms , Diagnostic Imaging , Magnetic Resonance Imaging , Mammography , Methods , Retrospective Studies
6.
Chinese Journal of Medical Instrumentation ; (6): 290-293, 2019.
Article in Chinese | WPRIM | ID: wpr-772504

ABSTRACT

In this paper, the focus of technical review of the registration application data of digital Breast Tomosynthesis Mammography System was sorted out, so as to provide reference for researchers and manufacturers in China when applying for registration and preparation of such products.


Subject(s)
Humans , Breast , Diagnostic Imaging , Breast Neoplasms , Diagnostic Imaging , China , Mammography , Reference Standards , Radiographic Image Enhancement , Reference Standards , Risk Factors
7.
Journal of Southern Medical University ; (12): 192-200, 2019.
Article in Chinese | WPRIM | ID: wpr-772099

ABSTRACT

OBJECTIVE@#To develop a digital breast tomosynthesis (DBT) imaging system with optimizes imaging chain.@*METHODS@#Based on 3D tomography and DBT imaging scanning, we analyzed the methods for projection data correction, geometric correction, projection enhancement, filter modulation, and image reconstruction, and established a hardware testing platform. In the experiment, the standard ACR phantom and high-resolution phantom were used to evaluate the system stability and noise level. The patient projection data of commercial equipment was used to test the effect of the imaging algorithm.@*RESULTS@#In the high-resolution phantom study, the line pairs were clear without confusing artifacts in the images reconstructed with the geometric correction parameters. In ACR phantom study, the calcified foci, cysts, and fibrous structures were more clearly defined in the reconstructed images after filtering and modulation. The patient data study showed a high contrast between tissues, and the lesions were more clearly displayed in the reconstructed image.@*CONCLUSIONS@#This DBT imaging system can be used for mammary tomography with an image quality comparable to that of commercial DBT systems to facilitate imaging diagnosis of breast diseases.


Subject(s)
Female , Humans , Algorithms , Artifacts , Breast , Diagnostic Imaging , Mammography , Methods , Phantoms, Imaging , Radiographic Image Enhancement , Methods
8.
Chinese Journal of Interventional Imaging and Therapy ; (12): 251-254, 2018.
Article in Chinese | WPRIM | ID: wpr-702403

ABSTRACT

The dense breast notification legislation,which was passed by Connecticut in 2009,has attracted more attention to the dense breast.Now there is still no unified criterion nor global guide for reference to indicate additional supplemental screening tool suitable for women with dense breast.Ultrasonography and digital breast tomosynthesis became research focus.The progresses of these two technologies in dense breast were reviewed in this article.

9.
Chinese Journal of General Surgery ; (12): 1042-1045, 2018.
Article in Chinese | WPRIM | ID: wpr-734796

ABSTRACT

Objective To explore the diagnostic value of digital breast tomosynthesis technique (DBT) in breast suspicious calcified lesions.Methods Clinical data of 135 patients using DBT and FFDM (Full field digital mammography) was respectively analyzed.Results Of the 135 cases,43 cases were malignant,and 92 cases were benign.The diagnostic sensitivity DBT and FFDM were 93.0% (40/43)and 88.4% (38/43),specificity were 88.0% (81/92) and 75.0% (69/92),accuracy were 89.6% (121/135) and 79.3% (107/135),the differences were statistically significant (P <0.05).The ROC curve area (AUC) of DBT and FFDM were 0.905 ± 0.026 and 0.817 ± 0.034 (P =0.000 2).In premenopausal,postmenopausal and breast density ACR3-4 cases,DBT accuracy is higher than FFDM (P < 0.05).The BI-RADS classification difference of the benign calcified lesions was statistically significant (x2 =11.740,P =0.038 5).Conclusions Compared with the traditional FFDM,DBT has a higher value in the diagnosis of breast suspicious calcified lesions,especially for benign calcified lesions.

10.
Chinese Journal of General Surgery ; (12): 493-496, 2017.
Article in Chinese | WPRIM | ID: wpr-616443

ABSTRACT

Objective To evaluate the diagnostic value of breast mass-like lesions by digital breast tomosynthesis technique (DBT) versus full field digital mammography (FFDM).Methods 182 breast mass cases undergoing respectively DBT and FFDM diagnosis were reviewed to evaluate the the sensitivity,specificity and accuracy,breast BI-RADS classification and differences of edge character.Results Of the 182 cases,101 cases were malignant,81 cases were benign.DBT and FFDM in malignant mass detection rate were 95.0% and 95.0% respectively,the benign tumor detection rate were 80.2% and 80.2% respectively,the difference was statistically significant (P < 0.05).The diagnostic sensitivity was 93.1% (94/101) and 82.2% (83/101),specificity was 66.7% (54/81) and 53.1% (43/81),accuracy was 81.3% (148/182) and 69.2% (126/182),all the differences were statistically significant (P < 0.05).The BI-RADS classification difference of the malignant mass was statistically significant (x2 =12.912,P =0.044 5),and the benign mass was also statistically significant (x2 =12.739,P =0.026 0).The clear edge benign tumors detected by DBT and FFDM respectively were 65 and 45 cases (x2 =10.224,P =0.001 4).The spicule sign detected by DBT and FFDM respectively in malignant tumors were 71 and 50 cases (x2 =8.244,P =0.004 1).Conclusion DBT compared to traditional FFDM photography improves the lesion visibility,increases the diagnostic sensitivity and specificity,conducing to the identification of benign and malignant lesions.

11.
China Oncology ; (12): 487-495, 2017.
Article in Chinese | WPRIM | ID: wpr-616284

ABSTRACT

Background and purpose:Breast cancer is the most common malignancy in women. The new technology of mammography is helpful in breast cancer diagnosis. This study aimed to compare the efficacy of digital breast tomosynthesis (DBT) with conventional imaging methods in the diagnosis of benign and malignant breast lesions.Methods:During the period from Mar. 2015 to Dec. 2015, 227 patients with suspected lesions (by palpation or sonography) underwent further imaging exam in our hospital. The sonography, full-field digital mammography (FFDM), DBT and breast MRI were performed on all the patients. A double-blind assessment was carried out according to BI-RADS (version 2013) by experienced radiologists. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficiency of all methods, referring to the pathological data as the golden standard; the difference in the efficiency of DBT from the other methods was determined byZ-test.Results:Thirty patients were excluded for the unsatisfactory images, and 205 lesions (132 malignant and 73 benign lesions) were detected in the remaining 197 patients. Area under the curve (AUC) of sonography, FFDM, DBT, DBT+FFDM and MRI based on the BI-RADS were 0.8308, 0.8592, 0.9167, 0.9198, and 0.9354, respectively. The AUC of DBT was significantly higher than those of sonography (Z=7.36,P=0.0067) and FFDM (Z=4.89,P=0.0271), while there was no significantly difference between DBT and MRI (Z=0.02,P=0.9002) or FFDM+DBT (Z=0.69,P=0.4048).Conclusion:DBT could significantly improve the diagnostic performance for breast lesions compared with sonography and FFDM, providing a comparable efficiency to MRI. As a new mammography technology, DBT has good clinical application prospect.

12.
Chinese Journal of Medical Imaging Technology ; (12): 1349-1352, 2017.
Article in Chinese | WPRIM | ID: wpr-607683

ABSTRACT

Objective To compare the accuracy of full field digital mammography (FFDM) and digital breast tomosynthesis (DBT) in predicting size of ductal carcinoma in situ (DCIS).Methods Totally 30 women pateints with DCIS confirmed by histology were analyzed retrospectively.Two radiologists measured the size of the lesions on FFDM,DBT images respectively,and compared with pathological results.Two kinds of inspection methods correlation with pathology were compared with Pearson correlation analysis.Results Size of DCIS measured by doctor 1 and doctor 2 between FFDM and histology had correlation (r=0.857,0.818,both P<0.01),and those between DBT and histology also had correlation (r=0.924,0.885,both P<0.01).Intraclass correlation coefficient (ICC) of two doctors was 0.947 on FFDM,and 0.908 on DBT.Conclusion DBT provides a better estimation of the size of DCIS.Two physicians had high consistency for lesion size evaluation.For DCIS with microcalcifications,both FFDM and DBT provide smaller estimations compared with pathology,thus a bigger surgical resection of lesion is needed.

13.
Chinese Journal of Radiology ; (12): 828-833, 2017.
Article in Chinese | WPRIM | ID: wpr-667044

ABSTRACT

Objective To investigate the diagnostic value and characteristics of breast lesion in digital breast tomosynthesis (DBT) in combination with synthesized two-dimensional (2D) images. Methods The prospective study enrolled women older than 18 years with clinically suspected breast lesion.One hundred and sixty seven patients with 177 lesions confirmed by biopsy or surgery were included. All the patients underwent full-field digital mammography(FFDM)and DBT examinations,and synthesized 2D images(V-preview)were reconstructed from DBT.The images of FFDM,V-preview images and DBT plus FFDM, V-preview images were analyzed. The breast imaging reporting and data system (BI-RADS) and characteristic for predicting benign and malignant lesion were also evaluated.The average glandular dose for a single mammographic view between FFDM and DBT was recorded.The Nonparametric Z test was used to compare the differences among four different mammographic images in BI-RADS.The differential diagnostic performance among different mammography was evaluated by ROC analysis.Independent t test was used to compare the average glandular dose between FFDM and DBT.Results One hundred three benign lesions and 74 malignant lesions were confirmed. Compared with FFDM images alone or plus DBT,the diagnostic values of V-preview images alone/or plus DBT were not significantly different(Z=0.187 and 0.226,P=0.851 and 0.821), but compared with V-preview, the diagnostic values of V-preview images plus DBT revealed significant difference(Z=3.546,P<0.01).The area under ROC for V-preview plus DBT were 0.899,and the sensitivity,specificity,and accuracy were 90.5%,89.3%,and 89.3%,separately.For the average glandular dose, there was no significant difference between FFDM (1.48 ± 0.52) mGy and DBT (1.56 ± 0.39) mGy examination(t=1.714,P=0.087).Conclusion Synthesized 2D images from DBT,which may eliminate the need for FFDM,in combination with DBT can improve the diagnostic efficiency.

14.
Chinese Journal of Radiology ; (12): 483-487, 2015.
Article in Chinese | WPRIM | ID: wpr-477884

ABSTRACT

Objective To compare the diagnostic value of digital breast tomosynthesis (DBT) versus digital mammography (DM) in the evaluation mass like lesions in dense breasts. Methods Eight hundred and fifty eight patients, who had DBT and DM, with breast diseases confirmed by pathology were retrospectively reviewed. The breast density and the imaging features were classified according to the standard of American College of Radiology(2013) and breast imaging reporting and data system (BI?RADS) scores. Six hundred and thirty one patients with mass lesions in dense breasts were chosen to included. All 631 patients had DM of both breasts and DBT of affected breast prior to mastectomy. Pathological results were used as the golden standard. Detection rate and diagnostic accuracy of masses, sensitivity and specificity of diagnosis, false negative and recall rates, the margins and spicules and BI?RADS category were calculated. The detection rate and diagnostic accuracy, the margins and spicules of masses were compared with Chi?square test, the BI?RADS scores were analyzed with rank test. Results With DBT, average detection rate increased from 77.3%(488/631) to 84.3% (532/631), average diagnostic accuracy rate increased from 73.4%(463/631) to 82.3%(519/631),with statistical significant difference between groups (c2=27.191,36.890,P<0.01).Sensitivity for DBT and DM were 68.1%(205/301) and 58.8%(177/301), respectively. Specificity for DBT and DM were 95.2%(314/330)and 86.7%(286/330), respectively. Recall rate for DBT and DM were 3.6%(23/631)and 9.8%(62/631), respectively. One hundred and seventy two cases and 75 cases with circumscribed masses of benign cases were detected by DBT and DM, respectively. One hundred and eighty-two cases and 115 cases with spiculated masses of malignant cases were detected by DBT and DM, respectively, with statistical significant difference between groups (c2=70.471 and 21.707, P<0.01). Of 330 malignant cases, the numbers of BI?RADS category 0, 2, 3, 4A, 4B, 4C, 5 on DM images were 19,4,8,13,52,93,141, respectively, the numbers on DBT images were 3,1,7,5,52,83,179, respectively, with statistical significant difference(Z=-2.235,P=0.025). Of 301 benign cases, the number of BI?RADS category 0, 2, 3, 4A, 4B, 4C, 5 on DM images were 43,10,60,117,58,11,2, respectively, the number on DBT images were 20,4,64,150,55,7,1, respectively, with no statistical significant difference between groups(Z=-1.846,P=0.065). Conclusion DBT significantly improves the detection of mass?like lesions in dense breasts, display of mass margin and architectural distortion of surrounding tissue.

15.
Korean Journal of Radiology ; : 229-238, 2015.
Article in English | WPRIM | ID: wpr-183067

ABSTRACT

OBJECTIVE: To compare the diagnostic performance of digital breast tomosynthesis (DBT) and conventional breast ultrasound (US) to characterize breast lesions as benign or malignant. MATERIALS AND METHODS: A total of 332 women, presenting for screening examinations or for breast biopsy between March and June 2012 were recruited to undergo digital mammography (DM), DBT, and breast US examination. Among them, 113 patients with 119 breast lesions depicted on DM were finally included. Three blinded radiologists performed an enriched reader study and reviewed the DBT and US images. Each reader analyzed the lesions in random order, assigned Breast Imaging Reporting and Data System (BI-RADS) descriptors, rated the images for the likelihood of malignancy (%) and made a BI-RADS final assessment. Diagnostic accuracy, as assessed by the area under the receiver operating characteristic curve, sensitivity, and specificity of DBT and US were compared. RESULTS: Among the 119 breast lesions depicted on DM, 75 were malignant and the remaining 44 were benign. The average diagnostic performance for characterizing breast lesions as benign or malignant in terms of area under the curve was 0.899 for DBT and 0.914 for US (p = 0.394). Mean sensitivity (97.3% vs. 98.7%, p = 0.508) and specificity (44.7% vs. 39.4%, p = 0.360) were also not significantly different. CONCLUSION: Digital breast tomosynthesis may provide similar reader lesion characterization performance to that of US for breast lesions depicted on DM.


Subject(s)
Adult , Aged , Female , Humans , Middle Aged , Biopsy , Breast/pathology , Breast Neoplasms/diagnosis , Mammography/methods , ROC Curve , Radiographic Image Enhancement/methods , Retrospective Studies , Sensitivity and Specificity , Ultrasonography, Mammary/methods
16.
Chinese Journal of Radiological Medicine and Protection ; (12): 540-543, 2013.
Article in Chinese | WPRIM | ID: wpr-442012

ABSTRACT

Objective To study the angular dependence of four different mammographic dosimeters to monoenergetic X-ray beams and observe the variation tendency in angular dependence to different energy X-rays and to discuss the evaluation of average glandular dose(AGD)in digital breast tomosynthesis(DBT)system.Methods One ionization chamber and three semiconductor dosimeters were exposed by four kinds of beam quality.The signal of each dosimeter was tested over an angular range of 0° to 90°.The dosimeters were exposed for three times at each selected angular position.The measurement at each angle was normalized to the appropriate measurement at perpendicular incidence.Results The responses from all the dosimeters had a maximum at 0° and decreased with increasing angles.When the radiation incidence angle was 10°,the angular dependence were 0.99,0.99,0.96 and 0.96 for dosimeters A,B,C and D,respectively.And the angular dependence decreased to 0.96,1.00,0.78 and 0.52 when the incidence angle was up to 25°.For semiconductor dosimeters,no signal was recorded when incidence angle was beyond 45°.For ionization chamber,the magnitude of the angular dependence generally decreased with increasing energy.Conclusions All of the dosimeters will underestimate the dose if used in DBT.In order to minimize the error due to the rotation angle of X-ray tube,correction factor of mammography dosimeter should be used for the measurement of AGD in DBT systems.

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