Research on impedance imaging dates back to the early 1900s. In 1926, the journal Cancer Research published an article, "The electric capacity of tumors of the breast," [Volume 16: pp. 340-376, by H. Fricke and S. Morse of the Cleveland Clinic Foundation, Department of Biophysics]. This article discussed in vitro experimentation with impedance measurements and reported comparison of capacity of human tumors of several types with the capacitance of various normal tissues and found tumorous tissue to have a markedly lower capacitance than normal tissue. The article's concluding remark was: "Future applications of the method {of electric capacity measurement} may include the rapid searching of large masses of tissue for small concealed centers of malignancy and in certain important cases measurements may be made directly on the patient."
Impedance imaging technology has progressed significantly since the research by Fricke and Morse was published in 1926. Engineers at Siemens have worked on the impedance imaging principle for many years. The company TransScan Research and Development Co. Ltd. was founded in 1993 to develop a clinical impedance imaging (T-scan) system. By using the modern high-speed computer processors and advanced electronic and signal processing technologies now available, the impedance imaging principle has been integrated into a practical clinical technology.
T-scan imaging has been used clinically in Israel since the 1980s and extensive international clinical trials have been conducted since the early 1990s. The US Food and Drug Administration (FDA) evaluation process of the T-scan system took two years, the original FDA submission was made in 1997. The T-scan system was granted FDA pre-market approval (PMA) on April 19, 1999. Approximately 35 T-scan systems are now installed worldwide and new T-scan systems deliveries in the United States and throughout the world began in May 1999.
Widespread clinical use of T-scan imaging will undoubtedly lead to refinements and new uses of impedance imaging technology. Due to its low cost and ease of use, T-scan imaging will have an important impact on the fight against breast cancer around the world, particularly in countries that do not have widespread access to mammography (such as Ukraine). Detection of breast cancer at the earliest possible stage leads to the highest chance of successful treatment. T-scan imaging used together with mammography has the potential to help find breast cancer at an earlier stage in more women.
Updated: January 27, 2000
