This single-center, retrospective study aims to evaluate the utility of the color Doppler twinkling artifact feature in improving the visibility of breast tissue marker clips within breast tissue and axillary lymph nodes. The study population will consist of approximately 86 female patients (with 110 clips) who have undergone placement of breast tissue marker clips and have corresponding preoperative imaging data from GE-10 or Siemens ultrasound systems between October 2024 and October 2025. The primary endpoint is the proportion of subjects whose implanted clips exhibit the characteristic "twinkling artifact" on color Doppler ultrasound imaging, reported with a 95% confidence interval.

Inclusion Criteria:

• Female patients aged ≥18 years.
• Presence of suspicious breast lesions confirmed by ultrasound.
• Successful implantation of a breast tissue marker clip with accurate radiological documentation.
• Availability of preoperative breast ultrasound examinations (including B-mode and Color Doppler) performed using either a GE-10 or Siemens ultrasound system.
• Confirmation of clip placement via mammography, surgical specimen morphology, or same-day post-implantation ultrasound.

Exclusion Criteria:

• Pregnancy or lactation.
• History of ipsilateral breast malignancy or surgery.
• Presence of other metal implants potentially interfering with imaging.
• Suspicious mammographic microcalcifications in the target lesion.

People who have had a breast tissue marker clip placed in their breast or underarm area.