Interacting Factors of Strain Ratio Values in Fibroadenomas and the Contribution of Color Scale

The purpose of this retrospective study is to investigate the association of qualitative and semiquantitative strain elastography (SE) features with factors such as lesion size, skin-to-lesion distance, and patient's age in fibroadenomas and to discuss false-positive results.

A total of 120 lesions that were performed SE with histopathologically confirmed fibroadenoma were included in the study. All images were reviewed from the archiving system with a consensus of two radiologists. Tsukuba elasticity score was used for color scoring (from 1 to 5). Lesions with strain ratio (SR) ≥2.27 and color scale score of 4 or 5 were considered as false positive. The patients were divided into two groups according to the age: <50 and ≥50 years old. Regard of the size, lesions were divided into two groups: <15 mm and ≥15 mm. The distances of the lesions to the skin were also divided into two groups: <5 mm and ≥5 mm. Statistical analysis to identify associations between these groups and SR was carried out with Pearson Chi-square test and Fisher's exact test. The false-positive rates were calculated.

There was no statistically significant difference between patients' age, lesion size, skin-to-lesion distance, and SR values. The false-positive rate was 21.66% for SR, while it was 3.33% for color scale.

SR values of the fibroadenomas were not affected by factors such as age, lesion size, and depth. In addition, false-positive rates significantly decrease when color scale scores are evaluated for fibroadenomas.