Impact of digital breast tomosynthesis (DBT) on finding types leading to true-positive and false-positive examinations

PurposeTo investigate the frequencies of finding types with combined digital breast tomosynthesis (DBT) and digital mammography (DM) leading to true-positive (TP) and false-positive (FP) examinations.Materials and methodsConsecutive screening mammograms at an academic medical center from March 2008 to February 2011 (DM group) and from January 2013 to December 2017 (DBT/DM group) were retrospectively reviewed. Multivariable logistic regression models were used to compare the proportions of mammographic finding types leading to TP and FP examinations between the two groups.ResultsThe DM group had 554 TP and 7278 FP examinations, and the DBT/DM group had 1271 TP and 14,544 FP examinations. The finding type of calcifications led to a lower proportion of TP examinations in the DBT/DM than DM group (34.3% versus 47.7%, p < 0.001) but also a lower proportion of FP examinations (18.7% versus 21.7%, p < 0.001). Mass led to a higher proportion of TP examinations in the DBT/DM than DM group (5.7% versus 1.3%, p < 0.001) but also a higher proportion of FP examinations (4.6% versus 0.3%, p < 0.001). Asymmetry led to a higher proportion of TP examinations in the DBT/DM than DM group (58.3% versus 50.4%, p = 0.03) and a lower proportion of FP examinations (75.9% versus 77.6%, p < 0.001). Architectural distortion led a similar proportion of TP examinations in the DBT/DM and DM groups (1.7% versus 0.7%, p = 0.12) but a higher proportion of FP examinations (0.8% versus 0.4%, p = 0.007).ConclusionsMammographic findings leading to TP and FP examinations have shifted with the addition of DBT to DM.     

Lesion conspicuity on synthetic screening mammography compared to full field digital screening mammography

ObjectiveTo compare lesion conspicuity on synthetic screening mammography (SM) plus digital breast tomosynthesis (DBT) versus full field digital mammography (FFDM) plus DBT.Materials and methodsSeven breast imagers each prospectively evaluated 107–228 screening mammograms (FFDM, DBT, and SM; total 1206 examinations) over 12 weeks in sets of 10–50 consecutive examinations. Interpretation sessions alternated as follows: SM + DBT, then FFDM, or FFDM + DBT, then SM. Lesion conspicuity on SM versus FFDM (equal/better versus less) was assessed using proportions with 95% confidence intervals. DBT-only findings were excluded.ResultsOverall 1082 of 1206 (89.7%) examinations were assessed BI-RADS 1/2, and 124 of 1206 (10.3%) assessed BI-RADS 0. There were 409 evaluated findings, including 134 masses, 119 calcifications, 72 asymmetries, 49 architectural distortion, and 35 focal asymmetries. SM conspicuity compared to FFDM conspicuity for lesions was rated 1) masses: 77 (57%) equal or more conspicuous, 57 (43%) less conspicuous; 2) asymmetries/focal asymmetries: 61 (57%) equal or more conspicuous, and 46 (43%) less conspicuous; 3) architectural distortion: 46 (94%) equal or more conspicuous, 3 (6%) less conspicuous; 4) calcifications: 115 (97%) equal or more conspicuous, 4 (3%) less conspicuous. SM had better conspicuity than FFDM for calcifications and architectural distortion and similar conspicuity for most masses and asymmetries.ConclusionCompared to FFDM, SM has better conspicuity for calcifications and architectural distortion and similar conspicuity for most masses and asymmetries.     

Preoperative breast MR imaging in newly diagnosed breast cancer: Comparison of outcomes based on mammographic modality,breast density and breast parenchymal enhancement

PurposeTo compare the role of MR for assessment of extent of disease in women newly diagnosed with breast cancer imaged with digital mammography (DM) alone versus digital breast tomosynthesis (DBT).MethodsRetrospective review was conducted of 401 consecutive breast MR exams (10/1/2013–7/31/2015) from women who underwent preoperative MR for newly diagnosed breast cancer by either DM or DBT, leaving 388 exams (201 DM and 187 DBT). MR detection of additional, otherwise occult, disease was stratified by modality, breast density, and background parenchymal enhancement. A true-positive finding was defined as malignancy in the ipsilateral-breast >2 cm away from the index-lesion or in the contralateral breast.Results50 additional malignancies were detected in 388 exams (12.9%), 37 ipsilateral and 13 contralateral. There was no difference in the MR detection of additional disease in women imaged by either DM versus DBT (p = 0.53). In patients with DM, there was no significant difference in the rate of MR additional cancer detection in dense versus non-dense breasts (p = 0.790). However, in patients with DBT, MR detected significantly more additional sites of malignancy in dense compared to non-dense breasts (p = 0.017). There was no difference in false-positive MR exams (p = 0.470) for DM versus DBT. For both DM and DBT cohorts, higher MR background parenchymal enhancement was associated with higher false-positive (p = 0.040) but no significant difference in true-positive exams.ConclusionsAmong patients with DBT imaging at cancer diagnosis, women with dense breasts appear to benefit more from preoperative MR than non-dense women. In women imaged only with DM, MR finds additional malignancy across all breast densities.     

The effect of different exposure parameters on radiation dose in digital mammography and digital breast tomosynthesis: A phantom study

IntroductionThere are concerns regarding the increase in radiation dose among women undergoing both digital mammography (DM) and digital breast tomosynthesis (DBT). The aim of this study was to evaluate the effect of different exposure parameters on entrance skin dose (ESD) and average glandular dose (AGD) for DM and DBT using a phantom.MethodsThe ESD and AGD of 30 DM and DBT (cranio-caudal projection) examinations using a tissue equivalent phantom where acquired using a GE Senographe Essential DM unit. Commercial phantoms were used to simulate three different breast thicknesses and compositions. Tube potential, tube load, and target/filter combinations were also varied with ESD and AGD recorded directly from the DM unit. Comparisons were made using the non-parametric Kruskal Wallis, Mann–Whitney, and Wilcoxon signed rank tests.ResultsThe individual ESD values for 4 cm, 5 cm, and 6 cm thick phantoms for DM and DBT at Rh/Rh target/filter combination and 30–32 kV/56 mAs levels were 5.06 and 4.18 mGy; 5.82 and 5.08 mGy; and 7.26 and 11.4 mGy, respectively; while AGDs were 1.57 and 1.30 mGy, 1.33 and 1.39 mGy; and 1.29 and 3.60 mGy, respectively. The Kruskal–Wallis test showed a statistically significant difference in AGD for DM (P = .029) but not for DBT (P = 0.368). The Mann–Whitney and Wilcoxon signed rank tests showed no statistically significant difference for ESD or AGD between both DM and DBT techniques (P = .827 and .513). The percentage differences in ESD for phantom thicknesses of 4 cm, 5 cm, and 6 cm between DBT and DM ranged between −21% and 36%; while for AGD between −21% and 64.2%.ConclusionsThe ESD and AGD for single view projection in DM and DBT showed differences at 4 and 6 cm breast thicknesses and compositions but not at 5 cm thickness with 30–32 kV and a Rh/Rh target/filter combination.Implications for practiceA fibro-fatty breast results in less radiation dose variations in terms of ESD and AGD between DM and DBT techniques.     

Breast cancer detection: Comparison of digital mammography and digital breast tomosynthesis across non-dense and dense breasts

IntroductionBreast density is associated with an increase in breast cancer risk and limits early detection of the disease. This study assesses the diagnostic performance of mammogram readers in digital mammography (DM) and digital breast tomosynthesis (DBT).MethodsEleven breast readers with 1–39 years of experience reading mammograms and 0–4 years of experience reading DBT participated in the study. All readers independently interpreted 60 DM cases (40 normal/20 abnormal) and 35 DBT cases (20 normal/15 abnormal). Sensitivity, specificity, ROC AUC, and diagnostic confidence were calculated and compared between DM and DBT.ResultsDBT significantly improved diagnostic confidence in both dense breasts (p = 0.03) and non-dense breasts (p = 0.003) but not in other diagnostic performance metrics. Specificity was higher in DM for readers with >7 years' experience (p = 0.03) in reading mammography, non-radiologists (p = 0.04), readers who had completed a 3–6 months training fellowship in breast imaging (p = 0.04), and those with ≤2 years’ experience in reading DBT (p = 0.02), particularly in non-dense breasts.ConclusionDiagnostic confidence was higher in DBT when compared to DM. In contrast, other performance metrics appeared to be similar or better with DM and may be influenced by the lack of experience of the reader cohort in reading DBT.Implications for practiceThe benefits of DBT may not be entirely accrued until radiologists attain expertise in DBT interpretation. Specificity of DBT varied according to reader characteristics, and these characteristics may be useful for optimising pairing strategies in independent double reading of DBT as practiced in Australia to reduce false positive diagnostic errors.     

Breast tomosynthesis: A diagnostic addition to screening digital mammography

Objectives

Comparison between digital mammography alone and with adding digital breast tomosynthesis in breast cancer screening.

Outcomes by Race in Breast Cancer Screening With Digital Breast Tomosynthesis Versus Digital Mammography

PurposeDigital breast tomosynthesis (DBT) in conjunction with digital mammography (DM) is becoming the preferred imaging modality for breast cancer screening compared with DM alone, on the basis of improved recall rates (RR) and cancer detection rates (CDRs). The aim of this study was to investigate racial differences in the utilization and performance of screening modality.MethodsRetrospective data from 63 US breast imaging facilities from 2015 to 2019 were reviewed. Screening outcomes were linked to cancer registries. RR, CDR per 1,000 examinations, and positive predictive value for recall (cancers/recalled patients) were compared.ResultsA total of 385,503 women contributed 542,945 DBT and 261,359 DM screens. A lower proportion of screenings for Black women were performed using DBT plus DM (referred to as DBT) (44% for Black, 48% for other, 63% for Asian, and 61% for White). Non-White women were less likely to undergo more than one mammographic examination. RRs were lower for DBT among all women (8.74 versus 10.06, P < .05) and lower across all races and within age categories. RRs were significantly higher for women with only one mammogram. CDRs were similar or higher in women undergoing DBT compared with DM, overall (4.73 versus 4.60, adjusted P = .0005) and by age and race. Positive predictive value for recall was greater for DBT overall (5.29 versus 4.45, adjusted P < .0001) and by age, race, and screening frequency.ConclusionsAll racial groups had improved outcomes with DBT screening, but disparities were observed in DBT utilization. These data suggest that reducing inequities in DBT utilization may improve the effectiveness of breast cancer screening.     

A randomised trial of screening with digital breast tomosynthesis plus conventional digital 2D mammography versus 2D mammography alone in younger higher risk women

IntroductionDigital breast tomosynthesis (DBT) has been shown to increase invasive cancer detection rates at screening compared to full field digital (2D) mammography alone, and some studies have reported a reduction in the screening recall rate. No prospective randomised studies of DBT have previously been published. This study compares recall rates with 2D mammography with and without concurrent DBT in women in their forties with a family history of breast cancer undergoing incident screening.Materials and methodsAsymptomatic women aged 40–49 who had previously undergone mammography for an increased risk of breast cancer were recruited in two screening centres. Participants were randomised to screening with 2D mammography only at the first study screen followed a year later by screening with 2D plus DBT, or vice versa. Recall rates were compared using an intention to treat analysis. Reading performance was analysed for the larger centre.Results1227 women were recruited. 1221 first screens (604 2D, 617 2D + DBT) and 1124 second screens (558 2D + DBT, 566 2D) were analysed. Eleven women had screen-detected cancers: 5 after 2D, 6 after 2D + DBT. The false positive recall rates were 2.4% for 2D and 2.2% for 2D + DBT (p = 0.89). There was a significantly greater reduction between rounds in the number of women with abnormal reads who were not recalled after consensus/arbitration with 2D + DBT than 2D (p = 0.023).ConclusionThe addition of DBT to 2D mammography in incident screening did not lead to a significant reduction in recall rate. DBT may increase reader uncertainty until DBT screening experience is acquired.     

Double reading of automated breast ultrasound with digital mammography or digital breast tomosynthesis for breast cancer screening

PurposeTo evaluate the impact of double reading automated breast ultrasound (ABUS) when added to full field digital mammography (FFDM) or digital breast tomosynthesis (DBT) for breast cancer screening.MethodsFrom April 2014 to June 2015, 124 women with dense breasts and intermediate to high breast cancer risk were recruited for screening with FFDM, DBT, and ABUS. Readers used FFDM and DBT in clinical practice and received ABUS training prior to study initiation. FFDM or DBT were first interpreted alone by two independent readers and then with ABUS. All recalled women underwent diagnostic workup with at least one year of follow-up. Recall rates were compared using the sign test; differences in outcomes were evaluated using Fisher's exact test.ResultsOf 121 women with complete follow-up, all had family (35.5%) or personal (20.7%) history of breast cancer, or both (43.8%). Twenty-four women (19.8%) were recalled by at least one modality. Recalls increased from 5.0% to 13.2% (p = 0.002) when ABUS was added to FFDM and from 3.3% to 10.7% (p = 0.004) when ABUS was added to DBT. Findings recalled by both readers were more likely to result in a recommendation for short term follow-up imaging or tissue biopsy compared to findings recalled by only one reader (100% vs. 42.1%, p = 0.041). The cancer detection rate was 8.3 per 1000 screens (1/121); mode of detection: FFDM and DBT.ConclusionsAdding ABUS significantly increased the recall rate of both FFDM and DBT screening. Double reading of ABUS during early phase adoption may reduce false positive recalls.     

Accuracy in tumor size measurements: Comparison of digital mammography,digital breast tomosynthesis and synthetic mammography

PurposeThe aim of this study was to assess the accuracy of digital mammography (DM), digital breast tomosynthesis (DBT) and synthetic mammography (SM) in tumor size measurements compared with histological tumor sizes.Materials and methods71 breast cancer patients who underwent DM and DBT acquisitions simultaneously were included in this study. One radiologist with 8 years of experience in breast imaging measured tumor sizes independently in three separate sessions which include DM, DBT and SM images, respectively. The correlations between the measured tumor sizes on each imaging technique and histological sizes were analyzed using Spearman correlation test. The patients were categorized into two subgroups according to assigned breast density categories (dense and non-dense), and histological tumor sizes (≤2 cm and > 2 cm). To assess the agreement levels between the measured tumor sizes and histological sizes Bland-Altman analyses were performed for each imaging technique.ResultsThe mean of histological size of tumors was 23.85 ± 16.57 mm (median: 20). The means of measured tumor sizes were 21.21 ± 13.59 mm (median: 19), 21.52 ± 13.42 mm (median: 19) and 18.97 ± 11.21 mm (median: 17) in DM, DBT and SM, respectively. The Spearman correlation values with histologic sizes were 0.814 (P < 0.001), 0.887 (P < 0.001), and 0.852 (P < 0.001) for DM, DBT and SM, respectively. In subgroup analyses, the correlation values showed decrement for tumors >2 cm in size compared to tumors ≤2 cm in size.ConclusionDBT provides the most accurate tumor size measurements among mammographic imaging techniques and if mammography will be used in tumor size measurements, DBT should be preferred.     

First ultrasound diagnosis of BI-RADS 3 lesions in young patients: Can 6-months follow-up be sufficient to assess stability?

ObjectivesTo evaluate the outcome of repeated short-term follow-up with ultrasound in no high-risk young patients with a BI-RADS3 lesion at first examination.MethodsIn this IRB-approved study 492 women, aged 18–34 years (mean ± standard deviation, 28 ± 4.5 years) with first breast ultrasound examination in 2012–2014 were retrospectively evaluated. Inclusion criteria were: at least one BI-RADS3 lesion and (a) biopsy/surgical excision or (b) follow-up of at least 18 months (including a 6-month follow-up). BI-RADS category assigned during follow-up and pathologic findings in cases undergoing biopsy/surgical excision were collected. At the 6- and 18-month follow-up the recommended biopsy rates (RBR) and the corresponding positive predictive value (PPV) were calculated.ResultsIn 97 patients, 151 BI-RADS3 lesions were identified. Biopsy/surgical excision was initially performed in 25/151 (16.5%) lesions. After 6-month, category was downgraded to BI-RADS1/2 in 23/126 (15.3%) and upgraded to BI-RADS4 in 9/126 lesions (7.1%). Pathological diagnosis of these lesions was fibroadenoma in 5 and benign phyllodes tumor in 4 cases (RBR 7%, PPV_bio 44.4%). After 18-month one lesion was classified BI-RADS4 and pathological diagnosis was fibroadenoma (RBR 1.1%, PPV_bio 0%).ConclusionsOur preliminary data show that follow-up imaging performed after 18 months from a first BI-RADS3 diagnosis does not affect clinical treatment and 6-month follow-up may be sufficient to assess the stability of probably benign lesions.     

Accuracy of tumour size assessment in the preoperative staging of breast cancer: comparison of digital mammography, tomosynthesis, ultrasound and MRI

Purpose

Accurate measurement of breast tumour size is fundamental for treatment planning. We compared the accuracy of digital mammography (DM), digital breast tomosynthesis (DBT), ultrasound (US) and magnetic resonance imaging (MRI) for the preoperative evaluation of breast cancer size.

Materials and methods

We retrospectively reviewed 149 breast cancers in 110 patients who underwent DM, DBT, US and MRI between January 2010 and December 2011, before definitive surgery. The lesions were measured by two radiologists, without knowledge of the final histological examination, considered the gold standard. For each imaging modality, the maximum tumour size was measured to the nearest millimetre; the measurements were considered concordant if they were within ±5 mm. Pearson’s correlation coefficient was calculated for each imaging modality.

Results

The median pathological tumour size was 22.3 mm. MRI and DBT had a level of concordance with pathology of 70% and 66%, respectively, which was higher than that of DM (54%). DBT and MRI measurements had a better correlation with pathological tumour size (R:0.89 and R:0.92, respectively) compared to DM (R:0.83) and US (R:0.77).

Conclusions

DBT and MRI are superior to DM and US in the preoperative assessment of breast tumour size. DBT seems to improve the accuracy of DM, although MRI remains the most accurate imaging modality for breast cancer extension.     

Assessment of the uterine dose in digital mammography and digital breast tomosynthesis

IntroductionDigital Mammography (DM-2D) and more recently Digital Breast Tomosynthesis (DBT), are two of the most effective imaging modalities for breast cancer detection, often used in screening programmes. It may happen that exams using these two imaging modalities are inadvertently performed to pregnant women. The objective of this study is to assess the dose in the uterus due to DM-2D and DBT exams, according to two main irradiation scenarios: in the 1st scenario the exposure parameters were pre-selected directly by the imaging system, while in the 2nd scenario, the maximum exposure parameters were chosen.MethodsThe mammography equipment used was a Siemens Mammomat Inspiration. A physical anthropomorphic phantom, PMMA plates (simulating a breast thickness of 6 cm) and thermoluminescent dosimeters (TLDs) were used to measure entrance air kerma values on the phantom's breast and abdomen in order to successively estimate the mean glandular dose (MGD) and the dose in the uterus. For the two irradiation scenarios chosen, two-breast imaging modalities were selected: 1) DBT in Cranio-Caudal (CC) view (with 28 kV and 160 mAs as exposure parameters), 2) DBT and DM in Medio Lateral-Oblique (MLO) and CC views (with 34 kV and 250 mAs as exposure parameters).ResultsIn the 1st scenario, the TLD measurements did not detect significant dose values in the abdomen whereas the MGD estimated using the D.R. Dance model was in close agreement with data available in the literature. In the 2nd scenario, there was no significant difference in MGD estimation between the different views, whereas the air kerma values in the abdomen (in DBT mode, CC and MLO) were 0.049 mGy and 0.004 mGy respectively. In CC DM-2D mode the abdomen air kerma value was 0.026 mGy, with no significant detected value in MLO view.ConclusionsFor the dose in the uterus, the obtained values seem to indicate that DM-2D and DBT examinations inadvertently performed during pregnancy do not pose a significant radiological risk, even considering the case of overexposure in both breasts.Implications for practiceThe accurate knowledge of the doses in DM-2D and DBT will contribute to raise the awareness among medical practitioners involved in breast imaging empowering them to provide accurate information about dose levels in the uterus, improving their radiation risk communication skills and consequently helping to reduce the anxiety of pregnant women undergoing this type of examinations.     

Comparison of digital mammography and digital breast tomosynthesis in the detection of architectural distortion

Objectives

To compare interobserver variability (IOV), reader confidence, and sensitivity/specificity in detecting architectural distortion (AD) on digital mammography (DM) versus digital breast tomosynthesis (DBT).

Methods

This IRB-approved, HIPAA-compliant reader study used a counterbalanced experimental design. We searched radiology reports for AD on screening mammograms from 5 March 2012–27 November 2013. Cases were consensus-reviewed. Controls were selected from demographically matched non-AD examinations. Two radiologists and two fellows blinded to outcomes independently reviewed images from two patient groups in two sessions. Readers recorded presence/absence of AD and confidence level. Agreement and differences in confidence and sensitivity/specificity between DBT versus DM and attendings versus fellows were examined using weighted Kappa and generalised mixed modeling, respectively.

Results

There were 59 AD patients and 59 controls for 1,888 observations (59?×?2 (cases and controls)?×?2 breasts?×?2 imaging techniques?×?4 readers). For all readers, agreement improved with DBT versus DM (0.61 vs. 0.37). Confidence was higher with DBT, p?=?.001. DBT achieved higher sensitivity (.59 vs. .32), p?<?.001; specificity remained high (>.90). DBT achieved higher positive likelihood ratio values, smaller negative likelihood ratio values, and larger ROC values.

Conclusions

DBT decreases IOV, increases confidence, and improves sensitivity while maintaining high specificity in detecting AD.

Key points

? Digital breast tomosynthesis decreases interobserver variability in the detection of architectural distortion.? Digital breast tomosynthesis increases reader confidence in the detection of architectural distortion.? Digital breast tomosynthesis improves sensitivity in the detection of architectural distortion.

     

Estimation of percentage breast tissue density: comparison between digital mammography (2D full field digital mammography) and digital breast tomosynthesis according to different BI-RADS categories

Objective:

To compare breast density estimated from two-dimensional full-field digital mammography (2D FFDM) and from digital breast tomosynthesis (DBT) according to different Breast Imaging–Reporting and Data System (BI-RADS) categories, using automated software.

Methods:

Institutional review board approval and written informed patient consent were obtained. DBT and 2D FFDM were performed in the same patients to allow within-patient comparison. A total of 160 consecutive patients (mean age: 50±14 years; mean body mass index: 22±3) were included to create paired data sets of 40 patients for each BI-RADS category. Automatic software (MedDensity^©, developed by Giulio Tagliafico) was used to compare the percentage breast density between DBT and 2D FFDM. The estimated breast percentage density obtained using DBT and 2D FFDM was examined for correlation with the radiologists'' visual BI-RADS density classification.

Results:

The 2D FFDM differed from DBT by 16.0% in BI-RADS Category 1, by 11.9% in Category 2, by 3.5% in Category 3 and by 18.1% in Category 4. These differences were highly significant (p<0.0001). There was a good correlation between the BI-RADS categories and the density evaluated using 2D FFDM and DBT (r=0.56, p<0.01 and r=0.48, p<0.01, respectively).

Conclusion:

Using DBT, breast density values were lower than those obtained using 2D FFDM, with a non-linear relationship across the BI-RADS categories. These data are relevant for clinical practice and research studies using density in determining the risk.

Advances in knowledge:

On DBT, breast density values were lower than with 2D FFDM, with a non-linear relationship across the classical BI-RADS categories.To tailor screening and diagnosis protocols, it is important to identify females with an increased risk of breast cancer [1–3]. It has been estimated that females with dense breasts (breast densities of >75%) have 4–6 times higher risk of breast cancer than females with low breast densities [4] and that breast density is increasingly recognised as an independent determinant of breast cancer risk and possibly in prognosis [5]. Assessment of breast density is becoming crucial in epidemiological studies, including the estimation of breast cancer risk and assessing breast density-related risk over time, radiation dose monitoring and monitoring drug-related response [6,7].Different methods and classifications have been reported to assess breast density: the Tabar classification [8], Wolfe''s parenchymal patterns [9], and both semi-quantitative and quantitative computer-aided techniques [10–16]. The Breast Imaging–Reporting and Data System (BI-RADS) classification, considered as the additional quantitative scheme, is routinely used in the USA and was introduced to standardise reporting. Initially, it was based on four qualitative categories but an additional quantitative scheme was added in 2003, based on the extent of fibroglandular tissue [17]. Mammographic breast density estimation may be limited by the two-dimensional (2D) nature of the imaging technique, whereas a three-dimensional (3D) imaging modality, such as digital breast tomosynthesis (DBT), reduces the appearance of the overlapping parenchymal tissue and may therefore influence or alter density assessments [13,14]. In DBT, high-spatial-resolution tomographic images of the breast are reconstructed from multiple low-dose projection images acquired within a limited range of X-ray tube angles [15]. It has been demonstrated in a few studies that the automated estimation of breast density eliminates subjectivity between comparisons of full-field digital mammography (2D FFDM) and DBT and is more reproducible than a quantitative BI-RADS evaluation [14,16]. However, previous research mainly considered patients with relatively high breast density, with the possibility of the results not being applicable across all density categories and showing whether published percentage breast density differences between 2D FFDM and DBT apply to less dense or non-dense breasts. The purpose of our study was to compare the breast tissue density estimated using 2D FFDM and DBT among patients in a balanced data set of the four BI-RADS categories, using fully automated software.     

Effect of Arrival of Prior Mammograms on Recall Negation for Screening Mammograms Performed With Digital Breast Tomosynthesis in a Clinical Setting

PurposeThis retrospective study evaluates the effect of comparison with prior mammograms on recall negation for screening mammography performed with digital breast tomosynthesis (DBT) in a clinical setting and compares it with that performed without DBT.MethodsThis is an Institutional Review Board–approved, HIPAA-compliant retrospective review of the electronic medical record for all nonbaseline screening mammograms performed in clinical practice over 13 months. For each mammogram, we recorded if DBT were used, the BI-RADS assigned at initial interpretation, and whether prior mammograms were available at initial interpretation. If prior mammograms arrived later for comparison, the final BI-RADS assigned after comparison was recorded. A mammogram assigned a BI-RADS 0 at initial interpretation and assigned a BI-RADS 1 or BI-RADS 2 after prior mammograms arrived for comparison was labeled as a recall that was negated by the arrival of prior mammograms. The number of recalls negated for mammograms that used DBT was compared with that for mammograms that did not use DBT.ResultsArrival of prior mammograms for comparison negated the need for recall for mammograms performed with DBT by 67.67% and negated the need for recall for mammograms performed without DBT by 55.80%. After adjusting for age, density, and time between mammograms, the percentage of recalls negated by comparison with prior mammograms was not significantly different for mammograms performed with DBT than it was for those performed without DBT.ConclusionComparison with prior mammograms remains important for the minimization of recall rates during the use of DBT for screening mammography in the clinical setting.     

阅片者间应用数字乳腺断层合成X线成像诊断乳腺疾病的可靠性分析

目的：比较阅片者间应用全屏数字化乳腺 X 线成像(FFDM)和数字乳腺断层合成 X 线成像(DBT)对乳腺疾病诊断及BI-RADS 分类的差异,评价 DBT 在诊断乳腺肿瘤方面的应用价值。方法收集疑似乳腺疾病病例300例,所有病例均经手术病理证实,其中良性118例,恶性182例,所有患者术前均行 FFDM 及 DBT 检查。分别由4名不同年资医师独立阅片进行诊断,以病理为金标准,比较阅片者间对乳腺病变诊断的差异。采用χ2及受试者工作特征(ROC)曲线分析方法进行统计。结果高年资医师阅读 FFDM 和 DBT 的诊断正确率分别为90%和91%,曲线下面积(AUC)分别为0.891和0.899;低年资医师阅读 FFDM 和DBT 影像的诊断正确率分别为82%和90%,AUC 分别为0.801和0.891。118例良性病变中 DBT 相比 FFDM,高、低年资医师分类为 BI-RADS 4a 类及以下的病例分别由82例提高到96例、41例提高到98例,分类为 BI-RADS 4b-5类的病例分别由19例降至16例、30例降至16例。182例恶性病变中 DBT 相比 FFDM,分类为 BI-RADS 4a-5类的病例高、低年资医师分别由167例提高到169例、152例提高到167例;BI-RADS 4a 类及以下的病例分别由12例降至10例、24例降至15例。高、低年资医师阅读 FFDM 分类为 BI-RADS 0类的病例分别为22例和53例,而阅读 DBT 后二者分别降至7例和4例。结论不同年资医师阅读 DBT 可以提高诊断的准确性,BI-RADS 分类与病理结果的一致性亦更高,以低年资医师提高更为显著。DBT 对提高乳腺肿瘤的检出率及诊断准确性具有很大的潜能。     

The positive predictive value of the breast imaging reporting and data system (BI-RADS) as a method of quality assessment in breast imaging in a hospital population

Evaluation of the diagnostic performance of mammography and US in our hospital, based upon the positive predictive value (PPV) for breast cancer of the breast imaging reporting and data system (BI-RADS) final assessment categories, has been performed. A follow-up study of 2,762 mammograms was performed, along with 955 diagnostic exams and 1,807 screening exams. Additional US was performed in 655 patients (23.7%). The combined reports were assigned a BI-RADS category. Follow-up was obtained by pathologic examination, mammography at 12 months or from PALGA, a nationwide network and registry of histo- and cytopathology. Overall sensitivity was 85% (specificity 98.7%); sensitivity of the diagnostic examinations was 92.9% (specificity 97.7%) and of the screening examinations 69.2% (specificity 99.2%). The PPV of BI-RADS 1 was 5 of 1,542 (0.3%), and of BI-RADS 2, it was 6 of 935 (0.6%). BI-RADS 3 was 6 of 154 (3.9%), BI-RADS 4 was 39 of 74 (52.7%) and BI-RADS 5 was 57 of 57 (100%). The difference between BI-RADS 1 and 2 vs. BI-RADS 3 was statistically significant (P<0.01). Analysis of BI-RADS 3 cases revealed inconsistencies in its assignment. Evaluation of the BI-RADS final assessment categories enables a valid analysis of the diagnostic performance of mammography and US and reveals tools to improve future outcomes.     

Mammographic density estimation: one-to-one comparison of digital mammography and digital breast tomosynthesis using fully automated software

Objective

To compare breast density on digital mammography and digital breast tomosynthesis using fully automated software.

Methods

Following institutional approval and written informed consent from all participating women, both digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) were obtained. Breast percentage density was calculated with software on DBT and FFDM.

Results

Fifty consecutive patients (mean age, 51?years; range, 35–83?years) underwent both FFDM and DBT. Using a method based on the integral curve, breast density showed higher results on FFDM (68.1?±?12.1 for FFDM and 51.9?±?6.5 for DBT). FFDM overestimated breast density in 16.2% (P?P?r?=?0.54, P?r?=?0.44, P?Conclusion Breast density appeared to be significantly underestimated on digital breast tomosynthesis.

Key Points

• Breast density is considered to be an independent risk factor for cancer
• Density can be assessed on full-field digital mammography and digital breast tomosynthesis
• Objective automated estimation of breast density eliminates subjectivity
• Automated estimation is more accurate than BI-RADS quantitative evaluation
• Breast density may be significantly underestimated on digital breast tomosynthesis