We present experiments designed to test the applicability of the frequency-domain semi-infinite multi-distance method to cylindrical boundaries. Material with absorption and reduced scattering coefficients similar to those of tissue exposed to near-infrared light was cast into five cylindrical phantoms ranging in diameter from 4.2 to 10.2 cm, and also into a semi-infinite control. Measurements performed along the long axis of symmetry on the larger diameter cylinders reliably recovered both the absorption and the reduced scattering coefficients within 10% of the control values. Measurements performed along the circumference yielded values for these optical coefficients that differed significantly from the control values. These findings are explained by observing the measured frequency-domain parameters as functions of source-detector separation.
© 1996 Optical Society of AmericaPDF Article