Mohammad Eghtedari MD, PhD, Abstract Co-Author: Nothing to Disclose

Cherng Chao MD, JD, Presenter: Nothing to Disclose

Saharnaz Baghdadchi, Abstract Co-Author: Nothing to Disclose

Robert Frederick Mattrey MD, Abstract Co-Author: Nothing to Disclose

Sadik Esener, Abstract Co-Author: Nothing to Disclose

To determine if an optical core biopsy needle could be designed from fiber optic cables to differentiate bile from liver parenchyma and blood.

We developed a prototype fiber sensor based needle consisting of two optical fiber cables with 200 um core diameter and 0.22 numerical aperture assembled in a standard 15 cm 20 gauge.  One of fibers was connected to a light source composed of two red and green color laser diodes with a microcontroller to modulate the source lights.  The other fiber was used to transmit the backscattered photons detected at the tip of the needle to the detector. Three distinct wavelengths of 520, 630 and 700 nm were selected to determine the location of needle tip (Figure 2). Based on the optical properties of the tissue like absorption coefficient, scattering coefficient, and the anisotropy factor at the selected wavelengths, an algorithm was developed for determining the location of the needle tip using the detected backscattered light.  We tested the designed optical core biopsy needle using in a cadaveric poultry model composed of blood, bile and liver parenchyma.  

The measured intensity ratio of red to green light in blood was consistently more than 20, while this ratio for liver parenchyma was between 1.2 and 2. The measured intensity ratio of red to green light in bile was less  than 0.5.  These substantially different intensity ratios allowed easy differentation of bile from blood and liver parenchyma.

An optical core biopsy needle designed and implemented using fiber optic cables could successfully differentiated bile from liver parenchyma and blood in cadaveric poultry specimens.

Our optical fiber based biopsy needle could be used in percutaneous hepatobiliary procedures to idenitfy the needle tip position based on the optical properties of tissue at the needle tip.

Eghtedari, M, Chao, C, Baghdadchi, S, Mattrey, R, Esener, S, Optically-assisted Needle Guidance to Differentiate Bile from Liver Parenchym and Blood.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045625.html