Interpretation of automated breast ultrasound (ABUS) with and without knowledge of mammography: a reader performance study

Abstract

Background: Automated breast ultrasonography (ABUS) has the potential to be an important adjunct to mammography in women with dense breasts. Purpose: To compare reader performance and inter-observer variation of ABUS alone and in combination with mammography. Material and Methods: This retrospective study had ethical committee approval. All women gave written informed consent. One hundred and fourteen breasts in 90 women examined by digital mammography and ABUS were interpreted by five radiologists using BI-RADS categories. The 114 breasts included 38 cancers and 76 normal or benign findings. In the first reading session ABUS only was interpreted, and in the second ABUS plus digital mammography. Image interpretations were done without knowledge of clinical or imaging results. A consensus panel analyzed false negative and false positive interpretations. Reading time was recorded for one radiologist. AUC was used for performance measurement, and kappa statistic for inter-observer variability. Results: Mean size for cancers was 16.2 mm; area under the curve (AUC) values for ABUS alone and for combined reading were, respectively: reader A, 0.592-0.744; reader B, 0.740-0.947; reader, C 0.759-0.823; reader D, 0.670-0.688; reader E, 0.904-0.923; and all readers combined 0.730-0.823. The higher AUC for combined reading was statistically significant (P < 0.05) for reader B and for all readers. There was a considerable inter-observer variability. Observer agreement revealed following kappa values for ABUS alone and combined reading, respectively: reader A, 0. 22-0.30; reader B, 0.33-0.44; reader C, 0.32-0.39; reader D, 0.07-0.14; and reader E, 0.34-0.43. Shadowing from dense parenchyma was the most common cause of false positive ABUS interpretations. Mean interpretation time for a bilateral normal ABUS examination was 9 min. Conclusion: Observer agreement was higher and all radiologists improved diagnostic performance using combined ABUS and mammography interpretation. Combined reading should be standard if ABUS is implemented in screening of women with dense breasts.

Adding 3D automated breast ultrasound to mammography screening in women with heterogeneously and extremely dense breasts: Report from a hospital-based, high-volume, single-center breast cancer screening program

“…The setup of our study was similar to the Somoinsight study by Brem et al [11] and the reader performance studies by Skaane et al [30] and GIGER et al [21]. In all three studies the first reader assessed the mammogram and then 3D ABUS.…”

Automated breast ultrasound system (ABUS): reproducibility of mass localization, size measurement, and characterization on serial examinations

“…As mammography has limitations in detecting cancers that are hidden within the dense fibroglandular tissue, there is a need for an adjunctive screening device, which should be automated, user-friendly, acceptable to the patient, reproducible, and reliable (5,6). The results of a multicenter trial (7) using a supplemental screening breast ultrasound (US) for women at high risk with dense breast tissue have been promising; however, those results are plagued by a lack of reproducibility regarding lesion characterization, particularly for small lesions (8)(9)(10)(11)(12).…”

Current Status of Supplemental Screening in Dense Breasts

“…While technologists are encouraged to use the same scanning and documentation protocol, 19 standardized training is not generally available for technologists in the United States. With automated approaches, thousands of images are generated and interpretation times averaged 9 minutes for a bilateral examination in one early study, 24 compared to less than 0.5 minutes for a handheld examination with standard documentation. 19 For the patient, there is the additional barrier of out-of-pocket costs due to deductible and co-pays with most insurance in most states.…”