Method and system for ultrasonic tagging of fluorescence

Abstract

A method and system for localization of fluorescence in a scattering medium such as a biological tissue are provided. In comparison to other optical imaging techniques, this disclosure provides for improved spatial resolution, decreased computational time for reconstructions, and allows anatomical and functional imaging simultaneously. The method including the steps of illuminating the scattering medium with an excitation light to excite the fluorescence; modulating a portion of the emitted light from the fluorescence within the scattering medium using an ultrasonically induced variation of material properties of the scattering medium such as the refractive index; detecting the modulated optical signal at a surface of the scattering medium; and reconstructing a spatial distribution of the fluorescence in the scattering medium from the detected signal.

Description

BACKGROUND OF THE INVENTION [0001] This disclosure relates generally to medical imaging systems, and more particularly, to methods and systems for localization of fluorescent dyes in a scattering medium, e.g., biological tissue. [0002] Millions of women participate in x-ray mammography each year. The specificity of this exam for radiologically dense breasts is not optimal. Suspicious lesions are subject to follow-up with other modalities such as ultrasound imaging, and ultimately are likely to be examined by biopsy. The physical discomfort and psychological impact to the women who obtain false-positive results from this screening procedure is immeasurable. The low sensitivity of the procedure gives rise to a high number of false negative results. This, in turn, leads to later stage detection of the disease and poorer patient prognostics. The rate of women having x-ray mammography screening is increasing annually, which leads to an overall earlier detection of suspect lesions. Howeve...

AI Technical Summary

Benefits of technology

[0009] A method and system for localization of fluorescent dyes in a scattering medium such as a biological tissue are provided. In comparison to other optical imaging techniques, this disclosure provides for improved spatial resolution, decreased computational time for reconstruction, and allows simultaneous anatomical and functional imaging using light-emitting agents.

Problems solved by technology

The specificity of this exam for radiologically dense breasts is not optimal.

The low sensitivity of the procedure gives rise to a high number of false negative results.

This, in turn, leads to later stage detection of the disease and poorer patient prognostics.

However, the increased frequency of mammography procedures, combined with the risks associated with the increased exposure to ionizing radiation brings into focus the clinical need for an alternate screening procedure that provides increased diagnostic sensitivity and specificity in radiologically dense breast tissue, that uses nonionizing radiation.

This limits the usefulness of this technique for deep tissue interrogation.

The instrumentation is typically more expensive as a consequence of increased hardware complexity.

Tomography is limited due to the severely ill-posed nature of the imaging system.

It is for this reason that generating reliable maps of the optical properties has proven difficult.

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