Ultrasound contrast enhancement in a typical mouse kidney following bolus injection of different lipid acyl-chain OMB, all sized to 2-10 µm, with MVD = 303.7 ± 9.8 µL/kg and volume fraction of 50%. A) Grayscale image of a mouse kidney in contrast mode with no OMB. Typically, a small ROI is used to avoid attenuation and shadowing effects; however, there were no indications of these effects and the entire kidney, indicated by a dashed line, was used for the ROI. Contrast enhancement in the kidney at peak enhancement after injection with OMB comprising (B) DSPC and (C) DBPC.