Mammography, Ultrasound, and Thermography: What are the Differences?
Source used for imaging
Mammography
- Uses X-rays (radiation) to produce an image that is a shadow of dense structures
- Contains radiation and is invasive
- Potential disadvantage: suspicious areas need to be dense enough to be seen
Ultrasound
- Uses high frequency sound waves
- The images are analyzed for any abnormalities or concerns
- Non-invasive and radiation-free
Calgary thermography
- Uses infrared sensors to detect heat and increased blood flow (angiogenesis)
- The heat images are analyzed for any abnormalities or concerns
- Non-invasive and radiation-free
Type of imaging
Mammography
- Anatomical (structural): Examines basis of changes caused by disease
- Ability to locate the exact area of suspicion
Ultrasound
- Anatomical (structural): Examines basis of changes caused by disease
- Ability to locate the exact area of suspicion
Calgary thermography
- Functional: Examines changes in metabolism, blood flow, regional chemical composition, and absorption
- Cannot locate the exact area of suspicision
Detection method
Mammography
- Early detection
Ultrasound
- Early detection
- Used as an adjunctive test. Cannot see fine detail; however, good at distinguishing solid masses from fluid-filled masses
Calgary thermography
- Early detection
- Used as an adjunctive imaging test
Cancer diagnosis
Mammography
- Findings indicate increased suspicion
- Biopsy is the only test that can determine if a suspected tissue area is cancerous
- CANNOT DIAGNOSE CANCER
Ultrasound
- Findings indicate increased suspicion
- Biopsy is the only test that can determine if a suspected tissue area is cancerous
- CANNOT DIAGNOSE CANCER
Calgary thermography
- Findings indicate increased suspicion
- Biopsy is the only test that can determine if a suspected tissue area is cancerous
- CANNOT DIAGNOSE CANCER
What can the imaging test detect?
Mammography
- May detect tumors in pre-invasive stage
Ultrasound
- Ability to detect some cancers missed by mammography
Calgary thermography
- May provide first signal that a problem is developing
- Positive thermal imaging represents the highest known risk factor for potential development of breast cancer up to 10 times more significant than any family history
Detection rate
Sensitivity: The likeliness that a test will pick up the presence of disease in a person.
Mammography
- Average sensitivity: 80 percent
- 20 percent of cancers missed; women over age 50
Ultrasound
- Average sensitivity: 83 percent
- 17 percent of cancers missed; all age groups
Calgary thermography
- Average sensitivity: 90 percent
- 10 percent of cancers missed; all age groups
Factors that can affect the imaging test
Hormone use
Mammography
- YES
Ultrasound
- NO
Calgary thermography
- NO
Large, dense, and fibrocystic breast, resulting in reading difficulties
Mammography
- NO
Ultrasound
- NO
Calgary thermography
- NO
Peripheral areas next to chest wall and inframammary sulcus cannot be visualized; in most women
Mammography
- YES
Ultrasound
- NO
Calgary thermography
- NO
Sources: Index Medicus – ACS, NEJM, JNCI, J Breast, J Radiology, J Clin Ultrasound / Index Medicus – Cancer, AJOG, Thermology / Text – Atlas of Mammography: New Early Signs in Breast Cancer / Text – Biomedical Thermology