Time–frequency based photoacoustic spectral response technique for differentiating human breast masses

Abstract

Breast cancer is the most prevalent form of cancer among women. Non-invasive and early stage diagnosis of breast cancer would be pragmatic to reduce unnecessary biopsy and mortality rate. We propose Wigner–Ville distribution (WVD) based photoacoustic spectral response (WVD-PASR), a tissue elasticity dependent technique for human breast cancer diagnosis. Since tissue elasticity acts as a finger print of many diseases including cancer, the proposed technique would differentiate normal from malignant breast masses. In addition, WVD is an advanced signal processing tool for time–frequency analysis which provides frequency domain parameters along with time information. This feature of WVD would elicit critical information about frequency component of the PA time domain signal. Since frequency content of PA signal is related to tissue elasticity, WVD-PASR would differentiate human breast masses. Applying the proposed technique on normal and malignant human breast tissues reveals that frequency analysis of malignant tissues contain two dominant peaks as compared to one dominant peak for a normal tissue. Besides having two dominant frequencies, the energy density of malignant breast is significantly more than that of normal tissue. Hence the proposed tool, in addition to detection of malignant breast tumours, could also provide tissue elasticity and other mechano-biological properties.