Implementation of Whole-Breast Screening Ultrasonography

To scan or not to scan: effect of scanning the axilla of all patients undergoing diagnostic breast ultrasound

BACKGROUND

Breast ultrasonography is a useful modality in patients undergoing diagnostic and screening breast imaging. However, breast ultrasound has a high false positive rate and can be time-consuming to perform.

PURPOSE

The purpose of this study was to evaluate the clinical impact of incidental axillary findings found on diagnostic breast ultrasounds at a single multi-site institution that has a standard protocol of scanning the axilla for all breast ultrasound exams.

METHODS

All diagnostic breast ultrasounds were retrospectively reviewed from January 2017 to September 2019. Follow-up imaging, relevant clinical history, and pathology results were also reviewed. All positive axillary findings were divided into incidental or non-incidental findings depending on whether there was a direct clinical indication to scan the axilla. Descriptive statistics were performed with a 5% level of significance.

RESULTS

Of the 19,695 diagnostic ultrasounds performed during this timeframe, there were 91 (0.5%) incidental axillary findings given a BIRADS category 3 or 4, and none of these findings resulted in the diagnosis of an occult breast cancer. One biopsy-proven SLL/CLL lymphoma was diagnosed that was otherwise clinically occult.

CONCLUSION

Routine axillary scanning in all patients undergoing a diagnostic breast ultrasound at a large multi-site institution yields a low rate of incidental findings and has minimal impact on detection of cancer.

Reproducibility of Automated Breast Ultrasonography and Handheld Ultrasonography for Breast Lesion Size Measurement

ABSTRACT

The purpose of our study was to evaluate the reproducibility of size measurement of breast lesions using automated breast ultrasonography (ABUS) compared with that with handheld ultrasonography (HHUS). Three breast radiologists performed HHUS and measured the lesions size in 2 different phantoms: lesions with various shape, size, and same stiffness (phantom 1) and lesions with same shape, size, and various stiffness (phantom 2). After 1 month, the same radiologists measured the lesion size of the same breast phantoms in the images obtained using ABUS. We evaluated interobserver variability between 3 radiologists in ABUS and HHUS, and intraobserver variability of radiologists between ABUS and HHUS. Intraclass correlation coefficient (ICC) was used in statistical analysis. The measured size of lesions on HHUS was slightly larger than that on ABUS in both phantom 1 and 2, although not statistically significant (P = 0.314, P = 0.858). There were no significant differences in size measurements between the radiologists' measurements and the reference size in phantom 2 (P = 0.862). The ICCs for the interobserver agreement between the 3 radiologists were 0.98 to 0.99 on ABUS and 0.99 to 1.00 on HHUS, respectively. The ICCs for the intraobserver agreement between ABUS and HHUS were 0.97 to 0.97 in phantom 1 and 0.98 to 0.99 in phantom 2. In conclusion, ABUS showed excellent interobserver and intraobserver agreement with HHUS in measuring size of the lesions, regardless of shape, size, and stiffness. Therefore, ABUS mixed with HHUS can be used reliably in following up breast lesions size.

Multiple Bilateral Circumscribed Masses (MBCM) at Screening Breast Ultrasound (US): Outcomes of New or Enlarging Masses at Follow-up

Background: Screening US has limited specificity but is increasingly performed given widening state and federal breast density legislations. There is a need for evidence-based management guidelines. Objective: To assess outcomes of new or enlarging oval circumscribed parallel (OCP) masses in the setting of multiple bilateral circumscribed masses (MBCMs) at sequential rounds of US screening. Methods: In this HIPAA-compliant retrospective study of women found to have MBCMs on screening breast US without mammography abnormalities, longitudinal review was performed to identify development of any new or enlarging or changing masses. Outcomes were recorded using biopsy results or minimum 12 months of follow-up as reference standards. Lesion characteristics, BI-RADS classification, breast density, patient age, demographics, and risk factors were reviewed. Statistical analysis included multivariable logistic regression analysis. Results: There were 284 (2.4%) cases of MBCMs in a total of 48,488 bilateral screening US exams performed in 11,826 asymptomatic women during January 2014 and July 2019 that fit inclusion criteria. Of the 284 women (mean age, 46; range, 20-83), 150 (52.8%) subsequently developed 465 new, enlarging and/or changing masses, 125 of which underwent biopsy (26.9%). Of the 465 masses, 408 (87.7%) were OCP and similar to other MBCMs; and 57 (12.3%) were unique findings that were non-oval non-circumscribed masses. None of the new or enlarging OCP masses were malignant. In total, malignancy rate was 0% for women with MBCMs with follow-up (median, 40.8 months; range, 12-75 months) and 0% for those that underwent biopsy (n=284) (95%CI, 0%, 1.2%). Of women with concurrent MBCM and unique findings, 4 cancers were detected. Three were new irregular masses, and one previously oval mass changed in morphology to have new calcifications and irregular border. A younger age was related to the likelihood of having enlarging masses (p<0.001). Conclusions: In the setting of MBCMs, new or enlarging OCP masses are a common and benign event. Concurrent new irregular masses or previously oval masses that develop suspicious morphologic features should be carefully evaluated for malignancy. Clinical impact: Breast radiologists who encounter new or enlarging OCP masses with no suspicious morphologic change in the setting of MBCMs can safely defer biopsies.

Comparison of the Diagnostic Performances of Ultrasound, High-Resolution Magnetic Resonance Imaging, and Positron Emission Tomography/Computed Tomography in a Rabbit Carotid Vulnerable Plaque Atherosclerosis Model

OBJECTIVES

Our study aimed to evaluate the diagnostic performances of 3 routine examination methods for cerebrovascular disease in a rabbit carotid artery atherosclerosis model.

METHODS

A total of 12 New Zealand rabbits were included: 4 in a control group and 8 in an experimental group. A clinically relevant atherosclerosis rabbit model was induced by left common carotid artery ligation and a 12-week high-fat diet. Atherosclerosis was further confirmed by a histopathologic analysis. Then carotid ultrasound (US) imaging, high-resolution magnetic resonance imaging (HRMRI), and positron emission tomography (PET)/computed tomography (CT) were performed on this model to evaluate the diagnostic performances.

RESULTS

Carotid US showed plaque formation in the left common carotid artery and little plaque in the right common carotid artery in the experimental group. In addition, HRMRI showed stenosis formation in the left common carotid artery in the experimental group. At the horizontal level, plaques were found in the left common carotid artery, and no plaques were found in the right common carotid artery in the experimental group. Also, PET/CT showed local hypermetabolism and vulnerable plaques in the left common carotid artery of the experimental group, whereas no hypermetabolism was found in the right common carotid artery of the experimental group. Moreover, the soft plaques detected by carotid US were different from the vulnerable plaques detected by PET/CT. The unstable plaques on HRMRI were the same as the hypermetabolic vulnerable plaques on PET/CT.

CONCLUSIONS

High-resolution MRI is recommended for the evaluation of neck and intracranial vascular stenosis and plaque properties in patients with stroke.

Automatic breast ultrasound: state of the art and future perspectives

The three-dimensional automated breast ultrasound system (3D ABUS) is a new device which represents a huge innovation in the breast ultrasound field, with several application scenarios of great interest.

ABUS's aim is to solve some of the main defects of traditional ultrasound, such as lack of standardization, high level of skill non-reproducibility, small field of view and high commitment of physician time. ABUS has proven to be an excellent non-ionising alternative to other supplemental screening options for women with dense breast tissue; also, it has appeared to be very promising in daily clinical practice.

The purpose of this paper is to present a summary of current applications of ABUS, focusing on clinical applications and future perspectives as ABUS is particularly promising for studies involving artificial intelligence, radiomics and evaluation of breast molecular subtypes.

Multiple Bilateral Circumscribed Breast Masses Detected at Imaging: Review of Evidence for Management Recommendations

OBJECTIVE. Historically, management recommendations for multiple bilateral circumscribed breast masses encountered with breast imaging have varied. This article reviews the evidence and provides best-practice recommendations for managing these masses. CONCLUSION. Meticulous imaging technique and interpretation are required to correctly diagnose multiple bilateral circumscribed breast masses. Radiologists should classify such masses identified at mammography, digital breast tomosynthesis, or bilateral whole-breast sonography as benign and recommend annual follow-up. Elucidating the significance of these masses on MRI, contrast-enhanced mammography, or nuclear breast imaging requires further study.

A comparative study on superb microvascular imaging and conventional ultrasonography in differentiating BI-RADS 4 breast lesions

This prospective study aimed to explore the diagnostic value of superb microvascular imaging (SMI) in differentiating Breast Imaging Reporting and Data System (BI-RADS) 4 breast lesions compared with conventional ultrasonography (US). A total of 111 patients with 116 breast lesions underwent grayscale ultrasound (US), colour Doppler flow imaging (CDFI) and SMI breast imaging between February 2016 and May 2018. CDFI and SMI were performed to evaluate vascular quantity, morphology, and distribution characteristics. The detection of malignancy was compared between grayscale US alone, US + CDFI and US + SMI in terms of the BI-RADS stratification system. SMI was observed to be significantly more accurate in distinguishing malignant breast lesions (86.67%) compared with CDFI (80.00%) (P<0.001). Among malignant lesions, SMI detected 80.00% of those that contained ≥4 vessels, while CDFI only detected 56.67%. Penetrating and branching vessels were identified by SMI in 53.33% of malignant breast lesions and by CDFI in 10.00%. There was no significant difference in vascular distribution by SMI (P=0.094) and by CDFI (P=0.087). US + SMI was associated with higher sensitivity, specificity, and accuracy rates (86.67, 83.72 and 84.48%, respectively) compared with US + CDFI (80.00, 72.09 and 74.14%, respectively). The area under the curve values from receiver operating characteristic analysis of US + SMI, US + CDFI and US alone were 0.852 [95% confidence interval (CI): 0.768–0.936)] 0.760 (95% CI: 0.660–0.860), 0.698 (95% CI: 0.589–0.807), respectively (P<0.001). SMI yielded more detailed vascular information associated with malignant breast masses when compared with conventional US. Therefore, as an adjunct to grayscale, SMI exhibited a markedly improved diagnostic capability in distinguishing malignant and benign breast lesions, particularly those of BI-RADS category 4.

Silicone-based composite materials simulate breast tissue to be used as ultrasonography training phantoms

A silicone-based composite breast phantom is fabricated to be used as an education model in ultrasonography training. A matrix of silicone formulations is tracked to mimic the ultrasonography and tactile response of human breast tissue. The performance of two different additives: (i) silicone oil and (ii) vinyl-terminated poly (dimethylsiloxane) (PDMS) are monitored by a home-made acoustic setup. Through the use of 75 wt% vinyl-terminated PDMS in two-component silicone elastomer mixture, a sound velocity of 1.29 ± 0.09 × 10³ m/s and an attenuation coefficient of 12.99 ± 0.08 dB/cm-values those match closely to the human breast tissue-are measured with 5 MHz probe. This model can also be used for needle biopsy as well as for self-exam trainings. Herein, we highlight the fabrication of a realistic, durable, accessible, and cost-effective training platform that contains skin layer, inner breast tissue, and tumor masses.

Dedicated computer-aided detection software for automated 3D breast ultrasound; an efficient tool for the radiologist in supplemental screening of women with dense breasts

OBJECTIVES

To determine the effect of computer-aided-detection (CAD) software for automated breast ultrasound (ABUS) on reading time (RT) and performance in screening for breast cancer.

MATERIAL AND METHODS

Unilateral ABUS examinations of 120 women with dense breasts were randomly selected from a multi-institutional archive of cases including 30 malignant (20/30 mammography-occult), 30 benign, and 60 normal cases with histopathological verification or ≥ 2 years of negative follow-up. Eight radiologists read once with (CAD-ABUS) and once without CAD (ABUS) with > 8 weeks between reading sessions. Readers provided a BI-RADS score and a level of suspiciousness (0-100). RT, sensitivity, specificity, PPV and area under the curve (AUC) were compared.

RESULTS

Average RT was significantly shorter using CAD-ABUS (133.4 s/case, 95% CI 129.2-137.6) compared with ABUS (158.3 s/case, 95% CI 153.0-163.3) (p < 0.001). Sensitivity was 0.84 for CAD-ABUS (95% CI 0.79-0.89) and ABUS (95% CI 0.78-0.88) (p = 0.90). Three out of eight readers showed significantly higher specificity using CAD. Pooled specificity (0.71, 95% CI 0.68-0.75 vs. 0.67, 95% CI 0.64-0.70, p = 0.08) and PPV (0.50, 95% CI 0.45-0.55 vs. 0.44, 95% CI 0.39-0.49, p = 0.07) were higher in CAD-ABUS vs. ABUS, respectively, albeit not significantly. Pooled AUC for CAD-ABUS was comparable with ABUS (0.82 vs. 0.83, p = 0.53, respectively).

CONCLUSION

CAD software for ABUS may decrease the time needed to screen for breast cancer without compromising the screening performance of radiologists.

KEY POINTS

• ABUS with CAD software may speed up reading time without compromising radiologists' accuracy. • CAD software for ABUS might prevent non-detection of malignant breast lesions by radiologists. • Radiologists reading ABUS with CAD software might improve their specificity without losing sensitivity.