Ji Hyun Youk MD, Abstract Co-Author: Nothing to Disclose

Eun Ju Son MD, PhD, Abstract Co-Author: Nothing to Disclose

Ah Young Park MD, Abstract Co-Author: Nothing to Disclose

Jeong-Ah Kim MD, PhD, Abstract Co-Author: Nothing to Disclose

Hye Mi Gweon MD, Presenter: Nothing to Disclose

To evaluate the diagnostic performance of lesion-to-fat elasticity ratio (Eratio) according to the location of the reference area in shear-wave elastography (SWE) for the diagnosis of breast cancers.

A total of 257 breast masses in 250 women who underwent SWE before core biopsy or surgery from February 2013 to August 2013 were retrospectively analyzed. For each mass, multiple quantitative Eratios were measured with a fixed region of interest (ROI) for the mass along with multiple ROIs for the surrounding normal fat in different locations. Logistic regression analysis with random effect was used to determine that Eratio was independently associated with breast cancers considering the location of ROI for the fat (depth, laterality, the actual or vertical distance from lesion, and the actual or vertical distance from the ROI of lesion). Quantitative mean (Emean) and maximum (Emax) elasticity values of the reference fat were divided into 4 groups according to their 25th percentile, median, and 75th percentile. Diagnostic performance of each group was evaluated using the area under the ROC curve (AUC).

At logistic regression analysis, Eratio showed a significant difference between benign and malignant lesions (P<0.0001), irrespective of the location of ROI for the fat (depth, laterality, the actual or vertical distance from the lesion, and the actual or vertical distance from the ROI of lesion). The 25th percentile, median, and 75th percentile of elasticity values of fat were 11.5 kPa, 16.9 kPa, and 25.3 kPa for Emean and 16.3 kPa, 24.7 kPa, and 35.7 kPa for Emax, respectively. The AUC of each group (<25th percentile, 25th percentile~median, median~75th percentile, and ≥75th percentile) was 0.973, 0.982, 0.967, and 0.954 for Emean and 0.977, 0.967, 0.966, and 0.957 for Emax, respectively. There was no significant difference in AUC among different 4 groups.

Eratio was independently associated with breast cancers when considering the location of the reference area. Eratio showed good diagnostic performance which was not influenced by the difference in elasticity value of reference fat.

Eratio in SWE can be expected to reduce the effect of precompression. Eratio was useful for the diagnosis of breast cancers with good performance independent of the location of reference area.

Youk, J, Son, E, Park, A, Kim, J, Gweon, H, Quantitative Lesion-to-fat Elasticity Ratio Measured by Shear-wave Elastography for the Diagnosis of Breast Cancers: Which Area Should be Selected as the Reference?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14004525.html