Avoiding potential sources of error in breast ultrasound elastography

Objectives: The main purpose of this study was to establish several factors which influence the quality of an elastographic examination in breast pathology.

Methods: In our ongoing study, which began in April 2007, we have examined 40 patients with focal breast lesions. All patients were examined using both 2D and Doppler ultrasound and elastography. The reference standard was the pathologic diagnosis. We tried to determine the importance of certain technical factors, such as: the type of section, the size of the region of interest, the degree of compression. We also studied in which way the characteristics of the lesion influence the elastogram.

Results: The elasticity score for the same lesion was sometimes different on sagittal and coronal sections – therefore it is important to examine the lesion using both types of sections and, probably, to take the highest elasticity score into account. If the region of interest was limited to the lesion, the elasticity score was not accurate, but if it included as much healthy tissue as possible, the score correlated better with the pathologic diagnosis. An inappropriate degree of compression also influenced the result of the examination. The elasticity score was more accurate for small masses than for large lesions, which occupied the whole field, and also for superficial lesions compared to deeper-situated ones.

Conclusions: Elastography is a useful tool in the non-invasive diagnosis of breast lesions, but it needs specific training, as well as acknowledging technical and pathological factors which may influence its sensitivity and specificity.