Comparison and validation of high frequency ultrasound detection techniques in a mouse model for renal tumors

The goal of this study is to compare and validate high frequency (20 - 50 MHz) ultrasound imaging techniques for early detection and follow-up of renal tumors in a murine Wilms´ tumor model. Mice (N = 16) were imaged every 3 to 4 days in vivo using a 25 MHz ultrasonic imaging system until tumor detection. For 8 mice, maximum tumor cross sections were then estimated from images along three orthogonal axes for confrontation with post-sacrifice caliper measurements. Tumor size in the 8 remaining mice was followed every 4 days up to 4, 8, 12 or 16 days. The mouse was then sacrificed and kidneys were imaged in situ (40 MHz or 50 MHz). Finally, histological study assessed tumor position and nature.