The primary difference between Stereotactic, Ultrasound-guided and MRI-guided biopsies lies in the method used to view the tissue under the skin’s surface while extracting samples. All three methods are effective and choosing one method over another depends highly upon the abnormality found during the breast screening.
Stereotactic biopsies use X-ray technology to view the tissue. Small amounts of radiation are used in this method which can be harmful. There is a rather high occurrence of samples deemed insufficient for testing. If pathology results are positive, a more invasive biopsy must be performed to support the result before a course of action may begin. The cost of this type of biopsy is significantly lower than that of other types and complications are rare.
Ultrasound-guided biopsies use sound waves to create an image of the breast tissue which eliminates the risks of radiation. It is useful in patients with more dense breast tissue that X-rays can not penetrate. A key benefit of using ultrasound is that images are in real time and show movements within the body at the time of the biopsy. This option does not have the ability to detect small mineral deposits in the breast, microcalcification, that may indicate a malignancy. Ultrasounds are more expensive than X-rays and not all insurance plans will cover them.
MRI-guided biopsies utilize Magnetic Resonance Imaging which generates a detailed 3-D picture of the breast tissue. This method does not involve radiation and is much more comfortable than Stereotactic biopsies. It is possible to image both breasts at the same time and can show abnormal or increased blood flow which is an early sign of cancer that is not visible by X-ray. MRI is not as effective in showing lesser aggressive noninvasive breast cancers. This method involves the use of intravenous dyes and often costs thousands of dollars more than Ultrasound or X-ray.