Development and characterisation of photoacoustic imaging phantoms

Abstract

This report explores the use of silicone and gelatin matrixes to develop photoacoustic imaging phantoms to replicate biological tissues such as colon tissues. These two host medium houses Intralipid-20% and three types of ink (India ink, Evans Blue, Direct Reds 81) as scattering agent and absorbing agent respectively. Investigations using laser-induced photoacoustic configuration were carried out to characterize thermal diffusivity properties of the prepared samples at 632.8nm. In particular, the effects of increasing concentration of Intralipid-20% and increasing volume of encapsulated ink on thermal diffusivity properties were investigated upon.

Theoretical results of thermal diffusivity of the proposed samples ranges between 0.4 – 7.4 X 10-4 m2s-1, some of which are in agreement with thermal diffusivity values of colon phantoms and pig‘s stratum corneum found in past publications. Thermal diffusivity value of a fresh pig‘s colon tissue was found to be comparable (3 ±0.15 X 10-4 m2s-1) with previously reported values for colon phantom tissue, therefore validating the reliability of the PAS experimental setup in this investigation.