Fig. 2. Normalized PA intensities of benign and malignant polyps.

Mean normalized PA intensities of benign and malignant polyps (A) at shorter wavelengths between 421 and 647 nm, and (B) at longer wavelengths between 692 and 917 nm. Error bars denote standard deviation. Malignant polyps had significantly higher PA intensities at 765, 787, and 853 nm compared to benign polyps.