Ultrasound Elasticity Imaging of Breast Fibroadenoma
Richard G. Barr M.D, PhD
Southwoods X-Ray and Open MRI, Youngstown, Ohio | 2006-11-21
A 42-year-old female patient presented with a palpable lump in the right breast. Mammography identified the lesion as a mass with a lobular appearance. Such lesions require further characterization using ultrasound technology. Imaging and physical findings must correlate, or continued close surveillance or biopsy based on palpation will be required. According to the American Cancer Society, 80% of biopsied breast lesions are found to be benign. Improved specificity of ultrasound characterization could help eliminate many of these biopsies while still detecting those that are malignant. A new technique, ultrasound elasticity imaging, was performed in order to visualize the relative stiffness of the lesion tissue in an elastogram.
The 2D-mode ultrasound image (left) confirms the presence of a mass which is taller than it is wide and has gentle lobulations (yellow arrows). These characteristics are suggestive of malignancy, thus classifying the lesion as a BIRAD 4.
The elastogram (right) depicts a dark area of tissue stiffness (yellow arrows) which is actually smaller than the lesion size observed in the corresponding 2D-mode image. Preliminary elastogram results indicate that lesions which appear smaller on the elasticity image are confirmed to be benign, while those lesions that appear larger are confirmed to be malignant. Elasticity imaging would predict this lesion to be benign.
The elastogram in this case helped diagnose the lesion as a fibroadenoma. This diagnosis was confirmed with an ultrasound-guided core biopsy. No additional diagnostic workup was required, and the patient was advised to return for routine follow-up of a benign lesion.
eSieTouch™ elasticity imaging was performed with a conventional ultrasound unit and a standard high-frequency linear ultrasound transducer. Software analysis of frame-to-frame difference in speckle pattern with mild compression allows for the display of the “softness” or “hardness” of a lesion - the strain image. “Hard” lesions (less strain) are visualized as black and “soft” lesions (more strain) as white. Thus fat is depicted as white and a hard cystic structure such as a fibroadenoma or a biopsy confirmed malignant lesion as black in the elastogram. The technique also provides information about the relative size of the stiffness area. If preliminary outcomes are confirmed in blind multicenter trials, the number of biopsies performed to diagnose breast lesions may be reduced.