Automated Volume Breast Ultrasound vs Hand-Held for Breast Imaging

How does accuracy compare in automated breast volume ultrasound and hand-held ultrasound?

Automated volume breast ultrasound (AVBS) is equal in diagnostic accuracy to hand-held (HH) ultrasound, whether performed by a sonographer or mammography technologist, according to a study presented at RSNA 2016.

Researchers from the United States and Italy sought to compare the diagnostic accuracy and inter-observer variability of HH US and a single volume using AVBS centered over the clinical abnormality and to compare if there is a significant difference if the AVBS is performed by a sonographer (UT) or mammography technologist (MT).

A total of 90 patients, median age 53.1, participated in the trial, undergoing diagnostic ultrasounds; 60 for a palpable mass, 25 for mammogram abnormality, one for follow-up study, and four for breast discharge. The patients were randomized to have either a HH or AVBS first. HH was performed using a 14MHz transducer. The AVBS was performed using a L15-9 transducer. The technologist performing the second study was blinded to results of the first exam. The AVBS was randomized between a UT and a MT. The studies were blinded, randomized, and read by two radiologists each with greater than 10 years’ experience in breast ultrasound. The lesion with the highest BI-RADS score was used in the analysis. The HH studies were read six months before the AVBS studies. Final diagnoses where made by core biopsy for follow-up for two years. Lesions included nine malignant lesions and 81 benign lesions.

The results showed that the K for benign/malignant was 0.831 (while the global agreement using a 7-point BI-RADS score was 0.488). The K agreement between AVBS and HH in detecting breast pathology was 0.831.

The first rater had a K of 0.910 (0.787-1.000) while the second 0.760 (0.578-0.943). The agreement between AVBS and HH was nearly the same when AVBS was performed by a MT (K=0.858 (0.723-0.963) or UT (k=0.803(0.596-1.000), p=0.47. The AUC for lesion characterization was AVBS reader 1 0.91 (0.84-0.96), AVBS reader 2 0.91 (0.83-0.96), HH reader 1 0.91 (0.84-0.96), and HH reader 2 0.83 (0.74-0.90) with no statistical difference. The inter-observer agreement based on BI-RADS was 0.568 (0.468-0.647), with the HH K of 0.631(0.584-0.665) and for AVBS 0.492 (0.457-0.564). The agreement based on pathology was K=0.831 (0.718-0.944) with HH K=0.795 (0.623-0.967) and AVBS 0.869 (0.725-1.000).

The researchers concluded that one view diagnostic AVBS was equivalent to a HH in diagnostic US work-up, and there was no difference if the AVBS is performed by a trained UT or MT.