A portable rectal near infrared (NIR) scanning polarization imaging unit with an optical fiber-based rectal probe, designated as a Photonic Finger (PF), was designed, developed, built and tested. PF was used to image and locate the three dimensional (3D) positions of abnormal prostate tissue embedded inside normal prostate tissue. An inverse image reconstruction algorithm, namely Optical Tomography using Independent Component Analysis (OPTICA) was developed to unmix the signal from targets (cancerous tissue) embedded in a turbid media (normal tissue) in the backscattering imaging geometry. The Photonic Finger combined with OPTICA was ex vivo tested to characterize different target(s) inside different tissue medium, including cancerous prostate tissue embedded inside large pieces of normal tissue. This new developed instrument, Photonic Finger, may provide an alternative imaging technique, which is accurate, of high spatial resolution and non-or-less invasive for prostate cancers screening.

Key words: Photonic finger (PF); Backscattering; Scanning optical polarization imaging; Optical fiber-based rectal probe; Three-dimensional localization; Human prostate tissue; Receptor-target contrast agents; Independent component analysis (ICA); Photon propagation model.