Purpose: This article describes an investigation of the detectability of breast microcalcifications by ultrasound imaging. Methods: Two kinds of experiments were performed to evaluate the spatial and contrast resolution of microstructures in an agar graphite phantom and to analyze human perception of tiny spots. Results: The results showed that most of the difficulties in finding microstructures were not only due to lower echo levels but also to obstructions in the surrounding texture of the image. Based on these results, a new image processing method was proposed to emphasize microcalcifications in mammary glands. This method utilized statistical analysis of the echo signals and also considered the structural pattern of the mammary gland. Processed images from some clinical cases showed adequate extraction of the microcalcifications with efficient cancellation of the mammary gland structure. Conclusion: The results suggested that the perception of microcalcifications could be improved by the proposed method.