How to Find an Isoechoic Lesion With Breast US

Abstract

Isoechoic lesions surrounded by fat can be a challenge for radiologists and can result in false-negative interpretations and a delayed diagnosis of breast cancer. Furthermore, isoechogenicity, including slight hypoechogenicity, as a common finding in breast lesions, is being reported in up to 84% of benign nodules and 30% of malignant lesions. Thus, about one-third of breast cancers may be described as isoechoic in actual clinical practice. Isoechogenicity can be seen in usual ductal hyperplasia, atypical ductal hyperplasia, papillary apocrine metaplasia, adenosis, debris and floating cells of complex cysts in the fibrocystic and benign proliferative conditions, fibroadenomas, and papillomas, as well as in about one-third of breast carcinomas. It is important to set the ultrasonic parameters, such as the dynamic range, total gain, and time-gain compensation curve, appropriately for comparison. Complementary tools to B-mode ultrasound in the evaluation of isoechoic breast lesions include spatial compound imaging, tissue harmonic imaging, ultrasound elastography, color or power Doppler imaging, power Doppler vocal fremitus imaging, and contrast agent enhancement.