Elastography imaging of small animal oncology models: a feasibility study

To test the feasibility of applying ultrasonic elastography on small animal oncology models, experiments were performed in vitro and in situ on murine mammary lesions induced exogenously by tumor cell line 66.3. In vitro studies involved three 1-week-old excised tumors embedded in a phantom block with ultrasonic properties similar to those of soft biologic tissues. In situ studies involved five mice whose bodies were embedded in pure gelatin blocks. The data were acquired from the blocks with a clinical scanner modified to have an automated compressor assembly and processed to construct the elastograms at various imaging planes within each block. The results were analyzed both qualitatively and quantitatively to assess the merits of the elastographic imaging and its limitations for in vivo serial studies of tumors in small animal oncology models.