Most biological soft tissues exhibit viscous behavior in addition to their well known elastic properties. Polyacrylamide gel based tissue mimicking phantoms have been developed. The viscoelastic properties of these phantoms were measured by subjecting the samples to cyclic loading. Samples prepared with varying concentration of monomer were considered so as to cover the normal and pathological lesions. Results obtained in the measurement are fit to three models - Maxwell, Kelvin-Voigt (KV) and Kelvin-Voigt fractional derivative (KVFD) models, in order to determine the best fitting model. KVFD model is found to be best fitting model for the experimental data obtained.

Many lesions remain undetected in normal ultrasound B mode imaging of cancerous tissues because of their isoechoic nature and poor contrast. Imaging of the elastic properties of tissue provides new information which is correlated with tissue pathology. A quantitative analysis of the improvement in the diagnosis of the tumor by combining the ultrasound B mode imaging and elastography is carried out. Quantification is based on the textural parameters measured from the ultrasound B mode image and strain measured from the elastogram. Polyacrylamide gel based tissue mimicking phantoms were used for the analysis.

Polyacrylamide based tissue mimicking phantom with embedded cysts is designed and analyzed for better understanding of cyst elastograms. Cysts filled with different fluids of varying density and bulk moduli are embedded in the phantom. Characterization is done based on parameters measured from the ultrasound B mode and elastogram of the cystic lesions. Such a phantom can serve as tool for better understanding of the elastographic appearance of cysts. Thus simple and complex cysts can be easily distinguished. It can also be used to teach a complex procedure like ultrasound guided fine needle aspiration.