Polarimetric measurement utility for pre-cancer detection from uterine cervix specimens

Abstract

Prior work demonstrated significant contrast in visible wavelength Mueller matrix images for healthy and pre-cancerous regions of excised cervical tissue. This work demonstrates post-processing compressions of the full Mueller matrix that preserve detection performance. The purpose of this post-processing is to understand polarimetric measurement utility for computing mathematical observers and designing future imaging protocols. The detection performance of the full Mueller matrix, and both linear and non-linear parameters of the Mueller matrix will be compared. The area under the receiver operating characteristic (ROC) curve, otherwise known as the <i>AUC</i>, is the gold standard metric to quantify detection performance in medical applications. An <i>AUC</i> = 1 is perfect detection and <i>AUC</i> = 0.5 is the performance of guessing. Either the scalar retardance or the 3 smallest eigenvalues of the coherency matrix yield an average <i>AUC</i> of 0.94 or 0.93, respectively. When these four non-linear parameters are used simultaneously the average <i>AUC</i> is 0.95. The J-optimal Channelized Quadratic Observer (J-CQO) method for optimizing polarimetric measurements demonstrates equivalent <i>AUC</i> values for the full Muller matrix and 6 J-CQO optimized measurements. The advantage of this optimization is that only 6 measurements, instead of 16 for the full Mueller matrix, are required to achieve this <i>AUC</i>.