Molecular breast imaging

Molecular Breast Imaging

Molecular Breast Imaging (MBI) is a diagnostic imaging technique used to detect breast cancer in women with dense breast tissue. It is a supplemental screening tool that can provide additional information when mammography results are inconclusive or suspicious.

Overview

MBI utilizes a small, specialized camera called a gamma camera to capture images of the breast. The camera detects the gamma rays emitted by a radioactive tracer that is injected into the patient's bloodstream. The tracer is specifically designed to bind to cancer cells, allowing the camera to visualize any areas of abnormality.

Unlike mammography, which uses X-rays to create images, MBI is not affected by breast density. This makes it particularly useful for women with dense breast tissue, as dense breasts can make it more difficult to detect abnormalities on a mammogram.

Procedure

The MBI procedure involves several steps:

1. Injection of the radioactive tracer: A small amount of a radioactive substance, such as Technetium-99m sestamibi, is injected into the patient's vein. The tracer travels through the bloodstream and accumulates in areas of increased metabolic activity, such as cancer cells.

2. Waiting period: After the injection, the patient typically waits for approximately 30-60 minutes to allow the tracer to distribute throughout the body.

3. Imaging: The patient lies on a table, and the gamma camera is positioned above the breast. The camera rotates around the breast, capturing multiple images from different angles. The images are then reconstructed to create a three-dimensional representation of the breast.

4. Interpretation: A radiologist analyzes the images to identify any areas of abnormality. The radiologist looks for areas of increased tracer uptake, which may indicate the presence of cancer.

Advantages and Limitations

MBI offers several advantages over other imaging modalities:

- Improved detection in dense breasts: MBI is particularly effective in detecting breast cancer in women with dense breast tissue, where mammography may be less reliable.

- Lower radiation exposure: MBI uses a lower dose of radiation compared to other nuclear medicine imaging techniques, such as positron emission tomography (PET).

- No compression: Unlike mammography, MBI does not require breast compression, which can be uncomfortable for some women.

However, MBI also has some limitations:

- False positives: MBI can sometimes produce false-positive results, leading to unnecessary additional testing or biopsies.

- Limited availability: MBI is not as widely available as mammography, and it may not be covered by all insurance plans.

Conclusion

Molecular Breast Imaging is a valuable tool in the detection and diagnosis of breast cancer, especially in women with dense breast tissue. It provides additional information when mammography results are inconclusive or suspicious. While it has its limitations, MBI offers improved detection rates and lower radiation exposure compared to other imaging modalities. Further research and advancements in technology may continue to enhance the effectiveness of MBI in the future.

See Also

• Breast cancer
• Mammography
• Nuclear medicine