Ultrasonic attenuation of canine mammary tumours

Canine mammary tumours (CMTs) are the most common neoplasm appearing in female dogs and are considered the equivalent animal model of human breast cancer. However, in the literature, there is a gap for ultrasonic characterisation of these tumours. In this study, experimental measurements for acoustic attenuation and propagation speed of three surgically excised malignant CMTs were implemented.

The three tumours were fixed in formaldehyde for up to 72 h and a total of five sample pieces were sectioned from the three tumours to account for the varied morphology observed along the tumours. The through-transmission and pulse-echo techniques were employed for experimental measurements of the acoustic attenuation and propagation speed.

Acoustic propagation speed of the five samples as measured at 2.7 MHz was in the range of 1568-1636 m/s. Correspondingly, acoustic attenuation was in the range of 1.95-3.45 dB/cm.MHz. Variations in both speed and attenuation were observed between samples acquired from the same tumour.

Present findings suggest that both acoustic attenuation and propagation speed of CMTs are higher than normal canine tissues due to increased heterogeneity and varied morphology visually observed between the tumour specimens and evidenced by histological examination. Nevertheless, experimental results could aid in enhancing the use of ultrasound in the diagnosis and treatment of CMTs as well as provide essential data for comparative oncology.