First clinical use of a standardized three-dimensional ultrasound for breast imaging

Automated Breast Volume Scanner Is More Valuable Than Hand-Held Ultrasound in Diagnosis of Small Breast cancer: An Analysis of 725 Patients With 912 Lesions Evaluations

ABSTRACT

This study aimed to evaluate the clinical value of automated breast volume scanner (ABVS) compared with hand-held ultrasound (HHUS). From January 2015 to May 2019, a total of 912 breast lesions in 725 consecutive patients were included in this study. κ statistics were calculated to identify interobserver agreement of ABVS and HHUS. The diagnostic performance for ABVS and HHUS was expressed as the area under the receiver operating characteristic curve, as well as the corresponding 95% confidence interval, sensitivity, and specificity. The sensitivities of ABVS and HHUS were 95.95% and 93.69%, and the specificities were 85.47% and 81.20%, respectively. A difference that nearly reached statistical significance was observed in sensitivities between ABVS and HHUS (P = 0.0525). The specificity of ABVS was significantly higher than that of HHUS (P = 0.006). When lesions were classified according to their maximum diameter, the sensitivity and specificity of ABVS were significantly higher than HHUS for lesions ≤20 mm, while they made no statistical significance between ABVS and HHUS for lesions >20 mm. The interobserver agreement for ABVS was better than that of HHUS. Automated breast volume scanner was more valuable than HHUS in diagnosing breast cancer, especially for lesions ≤20 mm, and it could be a valuable diagnostic tool for breast cancer.

Comparative analysis of automated breast volume scanner (ABVS) combined with conventional hand-held ultrasound and mammography in female breast cancer detection

Objective and background

This study aimed to compare the diagnostic value of an automated breast volume scanner (ABVS) combined with conventional hand-held ultrasound and mammography in detecting female breast cancer. Early detection is vital in improving patient outcomes for this prevalent disease.

Methods

Seventy-eight suspicious breast lesions from 60 patients were examined between August 2019 and July 2020. Each patient underwent ABVS, conventional hand-held ultrasound, and mammography. Diagnostic values, including coincidence rate, sensitivity, specificity, positive predictive value, and negative predictive value, were calculated using histopathology results as the "gold standard."

Results

Histopathology confirmed 55 malignant (70.51%) and 23 benign lesions (29.48%). ABVS combined with conventional hand-held ultrasound identified 56 malignant (52 confirmed, 4 benign) and 22 benign nodules (3 confirmed, 19 benign). Mammography detected 48 malignant (45 confirmed, 3 benign) and 30 benign nodules (10 confirmed, 20 benign). ABVS combined with conventional hand-held ultrasound had a sensitivity of 94.5%, specificity of 82.6%, positive predictive value of 92.9%, and negative predictive value of 86.4%. Mammography showed a sensitivity of 81.8%, specificity of 87.0%, positive predictive value of 93.8%, and negative predictive value of 66.7%.

Conclusion

ABVS combined with conventional hand-held ultrasound showed high diagnostic value in detecting female breast cancer. The "convergence sign" in the coronal section played a significant role. It slightly outperformed mammography and offered advantages in terms of cost, convenience, comfort, and absence of radiation. Further promotion and implementation are supported.

Evaluation of Diagnostic Performance of Automatic Breast Volume Scanner Compared to Handheld Ultrasound on Different Breast Lesions: A Systematic Review

Objective: To compare the diagnostic performance of the automatic breast volume scanner (ABVS) against the handheld ultrasound (HHUS) in the differential diagnosis of benign and malignant breast lesions. Methods: A systematic search and review of studies involving ABVS and HHUS for breast cancer screening were performed. The search involved the data taken from Scopus, PubMed, and science direct databases and was conducted between the year 2011 to 2020. The prospective method was used in determining the inclusion and exclusion criteria while the evidence level was determined using the BI-RADS categories for diagnostic studies. In addition, the parameters of specificity, mean age, sensitivity, tumor number, and diagnostic accuracy of the ABVS and HHUS were summarized. Results: No systematic review or randomized controlled trial were identified in the systematic search while one cross-sectional study, eight retrospective studies, and 10 prospective studies were found. Sufficient follow-up of the subjects with benign and malignant findings were made only in 10 studies, in which only two had used ABVS and HHUS after performing mammographic screening and MRI. Analysis was made of 21 studies, which included 5448 lesions (4074 benign and 1374 malignant) taken from 6009 patients. The range of sensitivity was (0.72–1.0) for ABVS and (0.62–1.0) for HHUS; the specificity range was (0.52–0.98)% for ABVS and (0.49–0.99)% for HHUS. The accuracy range among the 11 studies was (80–99)% and (59–98)% for the HHUS and ABVS, respectively. The identified tumors had a mean size of 2.1 cm, and the detected cancers had a mean percentage of 94% (81–100)% in comparison to the non-cancer in all studies. Conclusions: The evidence available in the literature points to the fact that the diagnostic performance of both ABVS and HHUS are similar with reference to the differentiation of malignant and benign breast lesions.

Associating Automated Breast Ultrasound (ABUS) and Digital Breast Tomosynthesis (DBT) with Full-Field Digital Mammography (FFDM) in Clinical Practice in Cases of Women with Dense Breast Tissue

The purpose of the present study was to evaluate the value of full-field digital mammography (FFDM) and automated breast ultrasound (ABUS) in the diagnosis of breast cancer compared to FFDM associated with digital breast tomosynthesis (DBT). Methods: This retrospective study included 50 female patients with a denser framework of connective tissue fibers, characteristic of young women who underwent FFDM, DBT, handheld ultrasound (HHUS), and ABUS between January 2017 and October 2018. The sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and accuracy of FFDM+ABUS were 81.82% (95% CI [48.22–97.72]), 89.74% (95% CI [75.78–97.13]), 69.23% (95% CI [46.05–85.57]), 94.59% (95% CI [83.26–98.40]), and 88% (95% CI [75.69–95.47]), while for FFDM+DBT, the values were as follows: 91.67% (95% CI [61.52–99.79]), 71.79% (95% CI [55.13–85.00]), 50% (95% CI [37.08–62.92]), 96.55% (95% CI [80.93–99.46]), 76.47% (95% CI [62.51–87.21]). We found an almost perfect agreement between the two readers regarding FFDM associated with ABUS, and substantial agreement regarding FFDM+DBT, with a kappa coefficient of 0.896 and 0.8, respectively; p < 0.001. Conclusions: ABUS and DBT are suitable as additional diagnostic imaging techniques to FFDM in women at an intermediate risk of developing breast cancer through the presence of dense breast tissue. In this study, DBT reduced the number of false negative results, while the use of ABUS resulted in an increase in specificity.

The diagnostic performance of automated versus handheld breast ultrasound and mammography in symptomatic outpatient women: a multicenter, cross-sectional study in China

OBJECTIVES

The purpose of this study was to evaluate the diagnostic performance of automated breast ultrasound (ABUS) for breast cancer by comparing it to handheld ultrasound (HHUS) and mammography (MG).

METHODS

A multicenter cross-sectional study was conducted between February 2016 and March 2017 in five tertiary hospitals in China, and 1922 women aged 30-69 years old were recruited. Women aged 30-39 years (group A) underwent ABUS and HHUS, and women aged 40-69 (group B) underwent additional MG. Images were interpreted using the Breast Imaging Reporting and Data System (BI-RADS). All BI-RADS 4 and 5 cases were confirmed pathologically. Sensitivities and specificities of all modalities were compared.

RESULTS

There were 83 cancers in 677 women in group A and 321 cancers in 1245 women in group B. In the whole study population, the sensitivities of ABUS and HHUS were 92.8% (375/404) and 96.3% (389/404), and the specificities were 93.0% (1411/1518) and 89.6% (1360/1518), respectively. ABUS had a significantly higher specificity to HHUS (p < 0.01), while HHUS had higher sensitivity (p = 0.01). In group B, the sensitivities of ABUS, HHUS, and MG were 93.5% (300/321), 96.6% (310/321), and 87.9% (282/321). The specificities were 93.0% (859/924), 89.9% (831/924), and 91.6% (846/924). ABUS had significantly higher sensitivity (p = 0.02) and comparable specificity compared with MG (p = 0.14).

CONCLUSION

ABUS increased sensitivity and had similar specificity compared with mammography in the diagnosis of breast cancer. Additionally, ABUS has comparable performance to HHUS in women aged 30-69 years old. ABUS or HHUS is a suitable modality for breast cancer diagnosis.

KEY POINTS

• In breast cancer diagnosis settings, automated breast ultrasound has a higher cancer detection rate, sensitivity, and specificity than mammography, especially in women with dense breasts. • Compared with handheld ultrasound, automated breast ultrasound has higher specificity, lower sensitivity, and comparable diagnostic performance. • Automated breast ultrasound is a suitable modality for breast cancer diagnosis, and may have a potential indication for its further use in the breast cancer early detection.

Diagnostic Performance of Automated Breast Ultrasound in Differentiating Benign and Malignant Breast Masses in Asymptomatic Women: A Comparison Study With Handheld Ultrasound

OBJECTIVES

Our aim was to investigate the diagnostic potential of an automated breast ultrasound (ABUS) system in differentiating benign and malignant breast masses compared with handheld ultrasound (HHUS).

METHODS

Women were randomly and proportionally selected from outpatients and underwent both HHUS and ABUS examinations. Masses with final American College of Radiology Breast Imaging Reporting and Data System categories 2 and 3 were considered benign. Masses with final Breast Imaging Reporting and Data System categories 4 and 5 were considered malignant. The diagnosis was confirmed by pathologic results or at least a 1-year follow-up. Automated breast US and HHUS were compared on the basis of their sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Diagnostic consistency and areas under the receiver operating characteristic curves were analyzed. The maximum diameters of masses were compared among HHUS, ABUS, and pathologic results.

RESULTS

A total of 599 masses in 398 women were confirmed by pathologic results or at least a 1-year follow-up; 103 of 599 masses were malignant, and 496 were benign. There were no significant differences between ABUS and HHUS in terms of diagnostic accuracy (80.1% versus 80.6%), specificity (77.62% versus 80.24%), positive predictive value (46.12% versus 46.46%), and negative predictive value (97.96% versus 95.67%). There were significant differences in sensitivity (92.23% versus 82.52%; P < .01) and areas under the curve (0.85 versus 0.81; P < .05) between ABUS and HHUS. The correlation of the maximum diameter was slightly higher between ABUS and pathologic results (r = 0.885) than between HHUS and pathologic results (r = 0.855), but the difference was not significant (P > .05).

CONCLUSIONS

Automated breast US is better than HHUS in differentiating benign and malignant breast masses, especially with respect to specificity.

Automatic Breast Volume Scanner versus Handheld Ultrasound in Differentiation of Benign and Malignant Breast Lesions: A Systematic Review and Meta-analysis

The goal of the study described here was to compare the automatic breast volume scanner (ABVS) and handheld ultrasound (HHUS) with respect to diagnostic performance in the differential diagnosis of benign and malignant breast lesions. A literature search of the PubMed, EMBASE and Cochrane Library databases through 30 June 2018 was conducted. Pooled sensitivity, specificity, positive and negative likelihood ratios and diagnostic odds ratios of the ABVS and HHUS were calculated, and summary receiver operating characteristic (SROC) curves were drawn. A total of nine studies, including 1985 lesions (628 malignant and 1357 benign) from 1774 patients, were analyzed. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio for ABVS were 90.8% (95% confidence interval: 88.3%-93.0%), 82.2% (80.0%-84.2%), 5.39 (4.26-6.80), 0.10 (0.06-0.15) and 61.68 (32.31-117.76); those for HHUS were 90.6% (88.1%-92.8%), 81.0% (78.8%-83.0%), 5.22 (3.14-8.67), 0.11 (0.08-0.17) and 52.60 (32.06-86.35), respectively. The areas under the SROC curves in the differentiation of benign and malignant breast lesions were 0.93 and 0.94 for ABVS and HHUS, respectively, which were not significantly different (p = 0.853). In conclusion, based on available evidence in the literature, ABVS the diagnostic performance of the ABVS is similar to that of HHUS in the differentiation of benign and malignant breast lesions.

Eye Movements in Medical Image Perception: A Selective Review of Past, Present and Future

The eye movements of experts, reading medical images, have been studied for many years. Unlike topics such as face perception, medical image perception research needs to cope with substantial, qualitative changes in the stimuli under study due to dramatic advances in medical imaging technology. For example, little is known about how radiologists search through 3D volumes of image data because they simply did not exist when earlier eye tracking studies were performed. Moreover, improvements in the affordability and portability of modern eye trackers make other, new studies practical. Here, we review some uses of eye movements in the study of medical image perception with an emphasis on newer work. We ask how basic research on scene perception relates to studies of medical 'scenes' and we discuss how tracking experts' eyes may provide useful insights for medical education and screening efficiency.

Image quality and artifacts in automated breast ultrasonography

Three-dimensional automated breast ultrasonography (ABUS) has been approved for screening Epub ahead of print studies as an adjunct to mammography. ABUS provides proper orientation and documentation, resulting in better reproducibility. Optimal image quality is essential for a proper diagnosis, and high-quality images should be ensured when ABUS is used in clinical settings. Image quality in ABUS is highly dependent on the acquisition procedure. Artifacts can interfere with the visibility of abnormalities, reduce the overall image quality, and introduce clinical and technical problems. Nipple shadow and reverberation artifacts are some of the artifacts frequently encountered in ABUS. Radiologists should be familiar with proper image acquisition techniques and possible artifacts in order to acquire high-quality images.

Evaluation of an automated breast volume scanner according to the fifth edition of BI-RADS for breast ultrasound compared with hand-held ultrasound

OBJECTIVES

To investigate the automated breast volume scanner (ABVS) in comparison with hand-held ultrasound (HHUS) according to the fifth edition of BI-RADS ultrasound.

MATERIAL AND METHODS

A total of 831 lesions in 786 patients who underwent both HHUS and ABVS were included. Three radiologists independently evaluated the sonographic features of each lesion according to the fifth BI-RADS edition. The kappa coefficient (κ) was calculated for each BI-RADS descriptor and final assessment category. The accuracy of malignancy prediction and diagnostic performance of the BI-RADS descriptors were assessed using multivariate logistic regression and area under the receiver operator characteristic curve (AUC), respectively.

RESULTS

ABVS and HHUS showed moderate to good interobserver agreement (κ = 0.53-0.67 and 0.55-0.70, respectively) except in associated features (κ = 0.31 and 0.36, respectively) for BI-RADS lexicons. Irregular shape, a non-circumscribed margin, and posterior features (combined or shadowing) were independently associated with malignancy in both ABVS and HHUS. Calcification presence on ABVS (odds ratio [OR], 95% confidence interval [CI]: 2.09, 1.11-3.94) and non-parallel orientation on HHUS (OR, 95% CI: 2.04, 1.10-3.78) were independently associated with malignancy. There were no significant differences between ABVS and HHUS in sensitivity (84.2% vs. 84.2%), specificity (80.5% vs. 83.9%), or AUC (0.88 vs. 0.90).

CONCLUSIONS

According to the fifth BI-RADS edition, ABVS is not statistically significantly different from HHUS with regard to interobserver variability and diagnostic performance.

Detectability and Usefulness of Automated Whole Breast Ultrasound in Patients with Suspicious Microcalcifications on Mammography: Comparison with Handheld Breast Ultrasound

Purpose

The purpose of this study was to prospectively evaluate the detectability and usefulness of automated whole breast ultrasound (AWUS) and to compare it with handheld breast ultrasound (HHUS) in cases with suspicious microcalcifications identified by mammography.

Methods

Forty-two patients with 43 suspicious microcalcifications (25 malignant and 18 benign) detected by mammography underwent AWUS, HHUS, and histol-ogic examination. With knowledge of the mammographic findings, HHUS was performed to assess the visibility of the microcalcifications and the presence of associated masses or ductal changes. Two radiologists reviewed the AWUS images in consensus using the same methods employed for HHUS. Detectability of AWUS was compared with that of HHUS and was correlated with histologic and mammographic findings.

Results

Of the 43 lesions, 32 (74.4%) were detectable by AWUS and 31 (72.1%) by HHUS. No significant differences in sensitivity were found between the two methods (p=0.998). AWUS detected 96% (24/25) of malignant microcalcifications and 44.4% (8/18) of benign microcalcifications. AWUS was more successful in the detection of malignant vs. benign lesions (96.0% vs. 44.4%, p=0.002), lesions >10 mm vs. ≤10 mm in size (86.7% [26/30] vs. 46.2% [6/13], p=0.009), lesions with a fine pleomorphic or linear shape vs. a round or amorphous or coarse heterogeneous shape (94.7% [18/19] vs. 58.3% [14/24], p=0.021), and lesions associated with a mass or architectural distortion vs. without obvious changes on mammography (100% [19/19] vs. 54.2% [13/24], p=0.022).

Conclusion

Detectability of AWUS was comparable to that of HHUS in cases where suspicious microcalcifications were identified on mammography. Therefore, AWUS might be helpful in the performance of ultrasound-guided percutaneous procedures for highly suspicious microcalcifications.

Comparison of automated breast ultrasonography to handheld ultrasonography in detecting and diagnosing breast lesions

BACKGROUND

Automated breast ultrasonography (ABUS) is increasingly used as a screening tool. Several studies have demonstrated a similar diagnostic performance for ABUS compared with handheld ultrasonography (HHUS), but the overall results have been controversial.

PURPOSE

To compare the clinical utility of ABUS and HHUS for detection and diagnosis of breast lesions.

MATERIAL AND METHODS

ABUS and HHUS images of suspicious breast lesions were obtained for 173 consecutive women scheduled to undergo ultrasonography (US)-guided or stereotactic biopsy. There were a total of 206 lesions, 46 of which were malignant and 160 benign. Three breast radiologists took part in this study: two reviewed the ABUS images, and the third reviewed all of the images, ABUS and HHUS, as well as the patients' medical records. The biopsied-lesion-detection rates were obtained. Using the Breast Imaging Reporting and Data System (BI-RADS), the images of the biopsied lesions were evaluated. Factors affecting ABUS detectability were analyzed.

RESULTS

The overall detection rates were 83.0% for ABUS and 94.2% for HHUS. Ten lesions were not detected on either HHUS or ABUS and these were microcalcifications (one malignancy and nine benign lesions). Of the 194 HHUS-detected lesions, 169 were detected by ABUS and 25 benign were not. ABUS less frequently detected lesions of smaller size as well as those of benign appearance and lower final-assessment category (P = 0.011 and P < 0.0001, respectively).

CONCLUSION

ABUS detected all of the malignant lesions that were detected on HHUS. ABUS missed several smaller benign lesions.

Gel pad application for automated breast sonography

The purpose of this study was to describe the technical aspects of gel pad application for automated breast sonography and to show its effects on pain relief, scan coverage, and image quality. Twenty patients underwent 2 sets of automated breast sonography with and without gel pad application and were then asked to provide feedback on the examination-related pain. Scan coverage and image quality were compared quantitatively and qualitatively. The degree of pain was significantly decreased after gel pad application (P < .0001). The scan coverage was expanded particularly at the mid-portion of the breast. Image quality was satisfactory without significant differences between the sets. Gel pad application for automated breast sonography is easy and provides significant pain relief. The scan coverage was expanded, while the image quality was maintained.

Automated breast volume scanning versus conventional ultrasound in breast cancer screening

RATIONALE AND OBJECTIVES

To assess the diagnostic value of automated breast volume scanning (ABVS) versus conventional ultrasound (US) in breast cancer screening.

MATERIALS AND METHODS

This study retrospectively analyzed the ABVS and US images from 200 women who underwent breast examination and were recommended for biopsy in our health management centers between July 22, 2011, and October 20, 2013. We retrospectively assessed whether breast lesions from 200 women, which were detected and classified by US, could be detected and classified by an independent examiner using only ABVS findings. The sensitivity and specificity of ABVS versus US in determining lesion malignancy were calculated using biopsy as the gold standard.

RESULTS

In the 200 cases, 273 and 194 individual lesions were detected by ABVS and US, respectively. All 194 US-detected lesions were detected by ABVS. Pathologic examination determined that, of the 273 total lesions, 251 lesions were benign and 22 lesions were malignant. US detected 21 of the 22 malignant lesions and ABVS detected all 22 malignant lesions. The sensitivity and specificity of ABVS relative to biopsy (gold standard) were 28.95% and 100%, whereas the sensitivity and specificity of US relative to biopsy were 43.06% and 98.36%.

CONCLUSIONS

US displays superior sensitivity to ABVS across all Breast Imaging Reporting and Data System (BI-RADS) density categories while displaying equivalent specificity with the exception of BI-RADS density category 1, in which ABVS displayed a slightly superior specificity. As ABVS possesses several advantages and limitations with respect to US, ABVS may serve as an effective, adjunct, screening tool to mammography and conventional sonography.

A novel breast ultrasound system for providing coronal images: system development and feasibility study

Breast ultrasound images along coronal plane contain important diagnosis information. However, conventional clinical 2D ultrasound cannot provide such images. In order to solve this problem, we developed a novel ultrasound system aimed at providing breast coronal images. In this system, a spatial sensor was fixed on an ultrasound probe to obtain the image spatial data. A narrow-band rendering method was used to form coronal images based on B-mode images and their corresponding spatial data. Software was developed for data acquisition, processing, rendering and visualization. In phantom experiments, 20 inclusions with different size (5-20 mm) were measured using this new system. The results obtained by the new method well correlated with those measured by a micrometer (y=1.0147x, R(2)=0.9927). The phantom tests also showed that this system had excellent intra- and inter-operator repeatability (ICC>0.995). Three subjects with breast lesions were scanned in vivo using this new system and a commercially available three-dimensional (3D) probe. The average scanning times for the two systems were 64 s and 74 s, respectively. The results revealed that this new method required shorter scanning time. The tumor sizes measured on the coronal plane provided by the new method were smaller by 5.6-11.9% in comparison with the results of the 3D probe. The phantom tests and preliminary subject tests indicated the feasibility of this system for clinical applications by providing additional information for clinical breast ultrasound diagnosis.

A semi-automated 3-D annotation method for breast ultrasound imaging: system development and feasibility study on phantoms

Spatial annotation is an essential step in breast ultrasound imaging, because the follow-up diagnosis and treatment are based on this annotation. However, the current method for annotation is manual and highly dependent on the operator's experience. Moreover, important spatial information, such as the probe tilt angle, cannot be indicated in the clinical 2-D annotations. To solve these problems, we developed a semi-automated 3-D annotation method for breast ultrasound imaging. A spatial sensor was fixed on an ultrasound probe to obtain the image spatial data. Three-dimensional virtual models of breast and probe were used to annotate image locations. After the reference points were recorded, this system displayed the image annotations automatically. Compared with the conventional manual annotation method, this new annotation system has higher accuracy as indicated by the phantom test results. In addition, this new annotation method has good repeatability, with intra-class correlation coefficients of 0.907 (average variation: ≤3.45%) and 0.937 (average variation: ≤2.85%) for the intra-rater and inter-rater tests, respectively. Breast phantom experiments simulating clinical breast scanning further indicated the feasibility of this system for clinical applications. This new annotation method is expected to facilitate more accurate, intuitive and rapid breast ultrasound diagnosis.

Radiologists' performance for detecting lesions and the interobserver variability of automated whole breast ultrasound

Objective

To compare the detection performance of the automated whole breast ultrasound (AWUS) with that of the hand-held breast ultrasound (HHUS) and to evaluate the interobserver variability in the interpretation of the AWUS.

Materials and Methods

AWUS was performed in 38 breast cancer patients. A total of 66 lesions were included: 38 breast cancers, 12 additional malignancies and 16 benign lesions. Three breast radiologists independently reviewed the AWUS data and analyzed the breast lesions according to the BI-RADS classification.

Results

The detection rate of malignancies was 98.0% for HHUS and 90.0%, 88.0% and 96.0% for the three readers of the AWUS. The sensitivity and the specificity were 98.0% and 62.5% in HHUS, 90.0% and 87.5% for reader 1, 88.0% and 81.3% for reader 2, and 96.0% and 93.8% for reader 3, in AWUS. There was no significant difference in the radiologists' detection performance, sensitivity and specificity (p > 0.05) between the two modalities. The interobserver agreement was fair to good for the ultrasonographic features, categorization, size, and the location of breast masses.

Conclusion

AWUS is thought to be useful for detecting breast lesions. In comparison with HHUS, AWUS shows no significant difference in the detection rate, sensitivity and the specificity, with high degrees of interobserver agreement.

Breast mass characterization using 3-dimensional automated ultrasound as an adjunct to digital breast tomosynthesis: a pilot study

OBJECTIVES

The purpose of this study was to retrospectively evaluate the effect of 3-dimensional automated ultrasound (3D-AUS) as an adjunct to digital breast tomosynthesis (DBT) on radiologists' performance and confidence in discriminating malignant and benign breast masses.

METHODS

Two-view DBT (craniocaudal and mediolateral oblique or lateral) and single-view 3D-AUS images were acquired from 51 patients with subsequently biopsy-proven masses (13 malignant and 38 benign). Six experienced radiologists rated, on a 13-point scale, the likelihood of malignancy of an identified mass, first by reading the DBT images alone, followed immediately by reading the DBT images with automatically coregistered 3D-AUS images. The diagnostic performance of each method was measured using receiver operating characteristic (ROC) curve analysis and changes in sensitivity and specificity with the McNemar test. After each reading, radiologists took a survey to rate their confidence level in using DBT alone versus combined DBT/3D-AUS as potential screening modalities.

RESULTS

The 6 radiologists had an average area under the ROC curve of 0.92 for both modalities (range, 0.89-0.97 for DBT and 0.90-0.94 for DBT/3D-AUS). With a Breast Imaging Reporting and Data System rating of 4 as the threshold for biopsy recommendation, the average sensitivity of the radiologists increased from 96% to 100% (P > .08) with 3D-AUS, whereas the specificity decreased from 33% to 25% (P > .28). Survey responses indicated increased confidence in potentially using DBT for screening when 3D-AUS was added (P < .05 for each reader).

CONCLUSIONS

In this initial reader study, no significant difference in ROC performance was found with the addition of 3D-AUS to DBT. However, a trend to improved discrimination of malignancy was observed when adding 3D-AUS. Radiologists' confidence also improved with DBT/3DAUS compared to DBT alone.

Effect of a gel retainment dam on automated ultrasound coverage in a dual-modality breast imaging system

OBJECTIVE

The goal of this work was to evaluate a possible improvement in ultrasound coverage for a dual-modality breast imaging system in the mammographic geometry.

METHODS

A pilot study was performed to evaluate use of a rubber dam to retain ultrasound gel and improve imaging coverage at the breast periphery on a combined imaging system consisting of an ultrasound scanner and a digital x-ray tomosynthesis unit. Several dams were constructed to encompass the shapes of various sizes of compressed breasts. Visual tracings of the breast-to-paddle contact area and breast periphery were made for 8 breasts to estimate coverage area. Two readers independently reviewed the resulting images and were asked to rate the overall breast image quality.

RESULTS

The percentages of breast in contact with the paddle were greater (P < .01) and the linear dimensions of breast in contact with the paddle were larger (P < .05) with the rubber dam than without it. With the dam, the mean estimated area of the breast in contact with the paddle increased 14%, whereas the mean increase in the fraction of the total breast area in contact with paddle was 30%. The difference was due to the mean total projected area of the breast decreasing 12% as the dam was pressed against it. The image quality of automated ultrasound with the rubber dam was consistently judged to be superior to that without the dam.

CONCLUSIONS

This method can enhance the absolute and percentage area of the breast in contact with the paddle, reducing noncontact gaps at the breast periphery. Gently pressing the breast periphery with the dam inserted toward the chest wall improves coverage in automated breast ultrasound scanning.