Fay A. Marks

General Electric Corporate Research and Development, One Research Circle, Niskayuna, NY 12309

Received 11/25/97 Accepted 12/5/97

5. SUMMARY

The In vitro and In vivo experiments performed strongly indicate that probing the oxygenation saturation of hemoglobin of the breast can provide a possible marker for distinguishing cancer from normal tissue and benign processes like fibrocystic disease. Fibroadenoma appears to be a false positive as it is for X-ray mammography and MRI. These results were harnessed in the design of a breast imager based on the modulation of light by ultrasound and may have potential as a diagnostic aid in a minimally invasive environment (22). It is important to note here that functional diagnostics using absorption spectroscopy performs equally well in fatty and fibroglandular breasts. Any imager or diagnostic device incorporating this technique would thus be an asset in the subpopulation of women with radiographically dense breasts.

Certainly, the area is ripe for further development and resolution of the inevitable issues that arise. One such issue is the fact that the depth of penetration of light is poor in the visible region which these studies concentrated on. Signal-to-noise considerations would dictate that a whole breast imager use near infrared light with its better tissue penetration; the 760 nm deoxyhemoglobin absorption resonance is a good candidate for spectral discrimination. For the minimally invasive environment, however, such as at the end of a biopsy needle (22), where signal-to-noise would not be an issue, the stronger resonances at 555 nm, 542 and 576 nm may be used.