Thermal imaging
Thermal imaging, also known as digital infrared thermal imaging (DITI) or thermography, is a non-invasive medical procedure that measures skin surface temperature by detecting infrared radiation emitted from the body. This technology is particularly noted for its potential in cancer detection, especially breast cancer, as tumors often present with higher metabolic rates that result in increased blood flow and elevated surface temperatures. While thermal imaging serves as an alternative screening method that avoids radiation exposure, it is not considered reliable for the early detection of breast cancer and should not replace traditional mammograms.
Patients are advised to prepare by maintaining normal blood circulation and avoiding factors that might alter body temperature, such as caffeine or strenuous exercise, before the procedure. During the imaging, patients are scanned with a thermal camera in a controlled environment to create thermal images, which are analyzed for patterns that could indicate abnormal conditions. The risks associated with thermal imaging are minimal, as it does not involve radiation or invasive procedures.
Despite ongoing research into enhancing its capabilities, including integration with artificial intelligence and advanced software techniques, thermal imaging is currently viewed as an adjunct tool rather than a primary screening method for breast cancer. Its limitations in visualizing internal structures further underscore the importance of traditional screening methods in cancer diagnostics.
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Subject Terms
Thermal imaging
ALSO KNOWN AS: Digital infrared thermal imaging (DITI), thermography
DEFINITION: Thermal imaging is a procedure to measure the skin surface temperature by detecting infrared radiation emitted from the circulation. Since tumors have higher metabolic rates than normal tissues, they tend to recruit and create more surrounding blood vessels than normal tissues to provide nutrients and oxygen for tumor cell survival. This process increases surface temperature, theoretically allowing tumor detection by observing abnormal temperature areas.
Cancers diagnosed:breast cancer
Why performed: Thermal imaging is a test to detect and monitor cancers. It is an alternative to other screening options that carry the risk of radiation exposure. Additionally, multiple images over time may aid in analyzing responses to treatment. However, studies have shown, and the United States Food and Drug Administrations has warned, thermal imaging is not reliable for early detection of breast cancer and should not replace mammograms as a cancer screening tool. It can be used in support of mammograms and breast ultrasound, especially for women with small or dense breasts or breast implants that may be difficult to test using those methods alone.
Patient preparation: Because thermal imaging measures temperature changes, patients should maintain normal circulation and body temperature before the imaging, including avoiding excessive sun exposure one week before testing. Also, patients should avoid hot water exposure, topical analgesics before testing, nicotine, caffeine, alcohol, strenuous physical exercise, and hot or cold beverages. Medications affecting the sympathetic nervous system may need to be withheld twelve to twenty-four hours prior to the evaluation.
Steps of the procedure: Patients will wear a hospital gown and lay on an examination table in a temperature-controlled room (68 degrees Fahrenheit) for approximately ten minutes to equilibrate the patient to the room temperature. Both sides of the body will be scanned with a thermal camera, also called an imaging radiometer, and the scans will be used as a thermal reference because of the body’s natural thermal symmetry.
After the procedure: After thermal images are taken, the patient does not need to take further action. The emitted infrared radiation is detected and converted into a monochrome or multicolored image, known as a thermogram, which is then displayed on a monitor screen.
Risks: The risks of this procedure are negligible since it is noninvasive and does not use tracer dyes, radiation, or chemicals.
Results: The thermal images are analyzed with the assistance of software programs, where shades or colors represent thermal patterns. The test results are deemed normal if the sides of the body are mirror images, indicating a symmetrical thermal pattern. Areas of increased heat, however, could indicate a potentially cancerous mass due to increased local blood vessels emitting more infrared radiation. Because thermal imagers cannot pinpoint specific tumor sites, an abnormal result would likely be followed up with other imaging or clinical laboratory tests.
Due to its limitations, thermal imaging cannot replace traditional mammography in breast cancer screening, and it is unlikely to do so in the future. Although research continues into thermal imaging for cancer screening, it is considered an adjuvant tool that should not replace traditional screening methods. Its inability to observe the internal structures of the breast limits thermal imaging’s effectiveness. Integration with artificial intelligence, techniques like thermographic signal reconstruction, and advances in software may improve thermal imaging's effectiveness in detecting cancer.
Bibliography
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