- Computerized Thermal Imaging
- Computed Tomography Laser Mammography
- Additional Resources and References
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The field of breast imaging is rapidly advancing at the beginning of the 21st century. While mammography remains the only exam approved by the U.S. Food and Drug Administration (FDA) to help screen for breast cancer in women with no signs or symptoms of the disease, there are several exciting developments in diagnostic breast imaging. Many of these technologies were showcased at the annual meeting of the Radiological Society of North America (RSNA) held this week in Chicago. One of the most recent advances in the field of mammography is digital mammography. Full-field digital (computerized) mammography is similar to standard mammography in that x-rays are used to produce detailed images of the breast. Digital mammography uses essentially the same mammography system as conventional mammography, but the system is equipped with a digital receptor and a computer instead of a film cassette. Full-field digital mammography has the potential to offer several advantages over traditional film mammography, including: faster image acquisition, shorter exams, easier image storage, easy transmission of images to other physicians, and computer processing of breast images for more accurate detection of breast cancer. The first full-field digital mammography system approved for use by FDA is the Senographe 2000D, made by General Electric (GE) Medical Systems. GE recently obtained FDA approval for "soft copy" reading of digital mammograms. Soft copy images are digital images that are interpreted on a computer monitor. Such soft-copy interpretation allows radiologists to use a high-resolution monitor and make adjustments for contrast and light intensity to better view the images. Currently, approximately 35 Senographe 2000D digital mammography systems are installed at locations across the United States and internationally. Several other manufacturers, including Siemens Medical Systems and Fischer Imaging Corporation, also introduced their digital mammography solutions at the annual meeting of the RSNA this November. Siemens Medical Systems will offer a mammography system equipped with both film/screen and digital capabilities. The digital component, developed together with Fuji Medical Systems, will allow mammography facilities to begin offering digital mammography by adding the digital component to their existing standard mammography system, thus eliminating some of the high cost associated with converting completely to digital mammography. Fischer Imaging introduced its SenoScan full-field digital mammography system at the RSNA. Both Siemens Medical and Fischer Imaging are applying for FDA approval for their digital mammography solutions. Other companies that are offering digital mammography solutions include Instrumentarium Imaging Inc., Hologic Inc., and Agfa Corp. In addition, Sectra-Imtec introduced its digital MicroDose Mammography system at the RSNA, which is still under development. The MicroDose system reduces the mammography radiation dosage by 20%. Click here to learn more about digital mammography. Computer-aided detection (CAD) is a new technology designed to help radiologists reduce interpretative errors by identifying and marking suspicious features on mammography films that may be associated with breast abnormalities. After the CAD technology marks possible breast abnormalities on a digitized mammogram film, the radiologist can review the film again, examining those suspicious regions more closely. Radiologists then decide whether additional diagnostic testing is necessary (such as ultrasound or biopsy). Many radiologists predict that CAD will gain more acceptance as digital mammography becomes widely available. Currently, the Imagechecker, made by R2 Technology, Inc. is the only FDA approved CAD system. Approximately 80 facilities worldwide are equipped with the R2 Imagechecker. In addition, CADx introduced its Second Look CAD workstation at the RSNA conference this November. The Second Look system also digitizes mammogram films and highlights suspicious areas for the radiologist to review. Scanis also showcased its Mammex TR CAD system, which is awaiting FDA approval. Click here to learn more about computer-aided detection for mammography. Transscan (also called T-scan, electrical impedance scanning or EIS) received FDA approval in 1999 as a new, non-invasive breast imaging exam. T-scan measures low level bioelectric currents to produce real-time images of the electrical impedance properties of the breast. The resulting impedance images of the breast tissue can be used to help determine if the region of interest is normal tissue or a cancerous tumor. Supplementing mammography with T-scan imaging or other breast imaging exams (such as ultrasound) may reduce the number of unnecessary breast biopsies and create savings in healthcare costs. Currently, T-scan is available at approximately 35 facilities worldwide. Click here to learn more about T-scan. Computerized thermal imaging (CTI) is a new breast imaging exam being developed to help detect breast cancer, when used in conjunction with mammography and other breast imaging exams. CTI is seeking pre-market approval, and at this time, they have received approval for three out of five modules of their application. The fourth and fifth modules will include clinical trial results. CIT is a non-invasive, heat sensing and processing system that uses a thermal sensitive camera to capture a digital image based on heat radiating from the body. A computer-assisted interpretation of the digital image helps to determine whether a local abnormality in breast tissue temperature is present, which may indicate the presence of disease. CTI is currently conducting clinical trials at five U.S. locations. Click here to learn more about computerized thermal imaging. Currently under development, computed tomography laser mammography (CTLM) is a breast imaging system that uses advanced laser technology to produce a near three-dimensional perspective of the breast. This detailed view may help radiologists see the extent and involvement of breast disease that is not visible in traditional two-dimensional imaging. According to Imaging Diagnostic Systems, Inc., the maker of CTLM, the system may be advantageous to physicians when deciding whether to recommend a patient for further diagnostic imaging or biopsy. To perform CTLM, the breast is placed in a scanned chamber. Without compressing the breast, a laser beam moves 360 degrees around the breast and acquires images in three-millimeter intervals. After all of the images are taken, they are reconstructed into a three-dimensional image of the breast, allowing the radiologist to view images of the breast from any plane.
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