About Breast Thermography
As a functional test, thermography can detect breast abnormalities that other screening methods cannot identify, namely thermal and vascular changes. These functional changes are thought to take place before the onset of structural changes that can occur in diseased or cancerous states. When functional abnormalities are detected early, there is an opportunity for early intervention. (1)
Thermography does not diagnose cancer; rather it can detect an abnormality and alert the physician to the need for further investigation and identify women who need to be more closely monitored. (2) IR imaging is not a competitor to, or a replacement for mammography, rather it is an adjunct tool that can identify areas of abnormal thermal symmetry which are often associated with underlying pathology. (3)
Thermography is a physiological test that provides information on temperature and infrared heat patterns of the breast. (4) Because the skin emits thermal radiation, it is well suited to infrared imaging. (5) As a functional test, thermography captures metabolic images. This technique differs from mammography which is a structural test that captures anatomical changes. (6)
Thermography records the temperature distribution of the body by using infrared radiation emitted from the surface of the skin at wavelengths between 0.8µm and 1.0µm. A special infrared camera detects this heat from the skin. The amount of radiated energy recorded by the camera is converted into an energy signal which in conjunction with other parameters calculates the temperature of the skin. A visual map (thermogram) of the distribution of temperatures on the surface of image is created which is recorded electronically. (7)
Just as a finger print is unique to an individual, so are breast thermal images. In a healthy woman, the symmetry between the two breasts while never identical is very similar. Likewise, vascularity between breasts in an otherwise healthy woman should also be consistent. In other words, a woman may exhibit minimal vascularity (cold breasts) or high levels of vascularity (warmer breasts), but the overall symmetry, heat emission and contours of the breasts should be comparable. (8) Because thermograms in a healthy woman remain remarkably constant, serial thermograms can assess tissue changes over time. A healthy initial thermogram can therefore serve as a baseline to compare future thermograms against. (1)
1. Kennedy DA, Lee T, Seely D. A comparative review of thermography as a breast cancer screening technique. Integr Cancer Ther. Mar 2009;8(1):9-16.
2. Isard HJ, Becker W, Shilo R, Ostrum BJ. Breast thermography after four years and 10000 studies. Am J Roentgenol Radium Ther Nucl Med. Aug 1972;115(4):811-821.
3. Jones CH, Greening WP, Davey JB, McKinna JA, Greeves VJ. Thermography of the female breast: a five-year study in relation to the detection and prognosis of cancer. Br J Radiol. Jul 1975;48(571):532-538.
4. Ng EY, Ung LN, Ng FC, Sim LS. Statistical analysis of healthy and malignant breast thermography. J Med Eng Technol. Nov-Dec 2001;25(6):253-263.
5. Joro R, Laaperi AL, Dastidar P, et al. Imaging of breast cancer with mid- and long-wave infrared camera. J Med Eng Technol. May-Jun 2008;32(3):189-197.
6. Plotnikoff G, Carolyn T. Emerging controversies in breast imaging: is there a place for thermography? Minn Med. Dec 2009;92(12):37-39, 56.
7. Gonzalez FJ. Infrared imager requirements for breast cancer detection. Conf Proc IEEE Eng Med Biol Soc. 2007;2007:3312-3314.
8. Isard HJ. Other imaging techniques. Cancer. Feb 1 1984;53(3 Suppl):658-664.