Why is T-scan Imaging of the Breast Performed?
- EIS/T-scan is Good for Imaging Denser Breasts in Younger Women
- EIS/T-scan is Used as a Supplement to Mammography
Electrical impedance imaging (EIS) has been developed for use in conjunction with mammography to assist in the diagnosis of breast cancer (carcinoma). The T-scan system is not yet available for use as a breast cancer screening tool. The T-scan is a non-invasive breast imaging system that assists in the detection of early stage tumors and pre-cancerous lesions without x-rays or discomfort to the patient. Unlike mammography or sestamibi nuclear medicine imaging, impedance imaging of the breast does not use radiation. T-scan impedance imaging does not require compression of the breast (which can be uncomfortable), and does not require a contrast media injection or biopsy sampling of the breast tissue via needle or surgical incision.
The T-scan measures low level bioelectric currents to produce real-time images of the electrical impedance properties of the breast. The resulting impedance images of the breast tissue can be used to help determine if the region of interest is normal tissue or a cancerous (malignant) tumor.
Younger women have more dense breast tissue than older women. Mammography does not show abnormalities or suspicious areas as well in younger women with dense breasts. This is because the x-rays do not penetrate dense tissue as well and thus the resulting mammogram image may have less contrast between an abnormal area and the surrounding breast tissue. Dr. Scott Fields, one of the researchers involved in the clinical trials of the T-scan systems found that impedance scanning works well for small lesions in younger patients with dense breasts as an adjunct to mammography.
Mammography is the only examination that is FDA approved for use as a breast cancer screening tool. In other words, mammography is the only imaging exam that is used to try to detect breast cancer in asymptomatic women (women who have no sign or symptom of breast cancer such as a lump).
However, in addition to electrical impedance imaging (EIS) of the breast, there are other imaging exams that are FDA approved for use as supplements (adjuncts) to mammography. One or more of these adjunct tools may be used when trying to determine if a suspicious area detected by mammography or physical breast exam is cancerous:
- Breast ultrasound
- Magnetic resonance imaging (MRI) of the breast
- Sestamibi nuclear medicine breast imaging (scintimammography)
- Electrical Impedance Imaging (EIS) of the breast (T-scan)
Microcalcifications, tiny calcium deposits in the breast which are often an early sign of breast cancer, can be seen reliably with mammography. About half of the cancers detected by mammography appear as a cluster of microcalcifications. The other tests listed above do not image calcifications as well as mammography. This is because MR imaging, ultrasound, nuclear medicine, and EIS do not provide the fine detail (spatial resolution) that is available with conventional x-ray mammography. However, these adjunct exams are beneficial because they provide excellent contrast resolution, which may make abnormalities easier to see since these areas "stand out" more from surrounding tissue.
- Diagnostically accurate, reliable, safe, and useful for distinguishing benign versus malignant lesions (abnormalities)
- Provides confident diagnosis and may help reduce the number of unnecessary breast biopsies performed
- Increases the early detection of breast cancer to improve treatment outcome
- T-scan imaging is non-invasive, does not use radiation and does not require breast compression which can be uncomfortable
- Works well in women of all ages, including young women, women with dense breast tissue and women under estrogen/hormone replacement therapy (HRT)
- May access and image the axillary lymph nodes
- Since there are no x-rays repeat examinations can safely be performed
- Like ultrasound and digital mammography, T-scan yields an immediate image (no delay waiting for film processing)
- The images are digital so they can be shared for consultation and archived easily
- The T-scan system is easy to use and requires minimal training for system operation
- The T-scan system is small and transportable and is cost effective to own and operate
Updated: January 27, 2000