How is Breast Thermography Performed?
Prior to a Digital Infrared Imaging examination (breast thermography), patients are asked to follow these recommendations: no sun exposure to the breasts 10 days prior to the exam; do not use deodorants, antiperspirants, powders, creams, lotions, body make-up, or hot/cold packs prior to the exam; avoid exercise 4 hours before the exam; no physical stimulation or treatment of the breasts for 24 hours prior to the exam; and refrain from bathing any closer than 1 hour before the exam.
The procedure for breast thermography begins with filling out a specialized health history which includes any current symptoms or past conditions that would impact upon the examination. The patient is then taken into the imaging lab where strict environmental controls are observed. The laboratory must be draft free, isolated from any outside infrared sources, and maintained at a temperature between 18-22 degrees Celsius (approx. 65-72 degrees Fahrenheit).
The patient is then disrobed to the waist and seated in a special chair where she is allowed to acclimate to the temperature of the room for 15 minutes before the scan is performed. Once this equilibration period is over, the patient is positioned in front of an ultra-sensitive infrared camera. A set of images are taken from different angles and sent to a computer for storage and analysis (these images are kept on archival media for precision comparison to future images so that the health of the breasts can be monitored over time). Sophisticated computer programs allow the doctor to isolate temperature differentials, perform vascular analyses, dynamic thermal subtraction studies, and more.
Once the images have been analyzed, they are graded using a strict standardized reading protocol. Each breast's image is placed into one of five thermobiological categories:
TH 1 - Normal non-vascular
TH 2 - Normal uniform vascular
TH 3 - Equivocal
TH 4 - Abnormal
TH 5 - Severely abnormal
Depending upon the results of the exam, further tests may be ordered and/or future infrared scans performed at recommended intervals to monitor the health of the breasts.
Bilateral Breast TH 1 - Normal Non-Vascular Image
The hotter the temperature the lighter the color (reds, oranges, yellows). Note that the color (temperature) patterns of the breasts are very close to identical when compared to each other.
Left Breast TH 4 - Abnormal Image
Note the increased temperature (metabolism) of the left breast. Within this area are three distinct focal spots of higher temperatures. Especially significant is the highly vascular focal hot spot closest to the left nipple.
Right Breast TH 5 - Severely Abnormal Image
Note the intensely increased temperature (metabolism) of the entire right breast. Especially significant are the high temperatures through the right nipple and into the lower portion of the breast. This is a patient with carcinoma in the right breast. Mammography and ultrasonography were found to be negative. This image served to direct precise physical examination which located the area for biopsy.
Dynamic Digital Thermal Subtraction
Dynamic digital thermal subtraction is a very sophisticated DII technique. If abnormalities are found on the initial scans, dynamic thermal subtraction images may be taken. The procedure consists of: (1) activating the sympathetic nervous system by challenging the body with a cold stimulus (this is non-toxic and harmless to the body), (2) taking a series of images over a specific time period, and (3) performing computerized subtraction of the images in order to evaluate the body's response.
Stimulation of the sympathetic nervous system causes a near shutdown of the normal blood vessels in the breast. The blood vessels supplying a cancerous tumor will not respond as they are held open by the tumor's chemical effects, etc. Consequently, dynamic digital thermal subtraction gives us the possibility of isolating the vessels that supply nutrients to the tumor. This test ultimately raises the suspicion that a cancerous tumor might be present.
Right Breast TH 2 - Normal Left Breast TH 4 - Abnormal
Again, note the increased temperature (metabolism) of the left breast. There are three suspicious focal areas of higher temperatures. Of highest suspicion is the highly vascular focal hot spot closest to the left nipple (#1).
Digital Subtraction Graph of the Left Breast (TH 4)
Once the cold challenge was complete, 50 images were collected over a 4-minute period. Four areas of blood vessel activity in the left breast were selected for analysis. These areas included the 3 suspected focal hot spots shown in the image above (noted as #1-3 on the graph). The computerized graphic analysis shows one vessel beginning as a cool area and progressively warming in a linear fashion. This single area displays a normal blood vessel response. However, blood vessels #1-3 begin as high temperature areas with #1 and #2 yielding the highest suspicion as they quickly level off with no further increase in temperature. Consequently, blood vessel areas #1 and #2 raise a high suspicion of either pre-cancerous or cancerous activity.
Digital Subtraction Graph of the Right Breast (TH 2)
Four similar areas of blood vessel activity in the right breast were selected for analysis. The computerized graphic analysis shows all four vessels beginning as cool areas and progressively warming in a nearly identical fashion. This graph displays the normal blood vessel responses to a sympathetic nervous system challenge.