Probably not. You can see pebbles of at least 5 mm. It should be noted that ultrasound devices are different, monitors for these devices are also different. The qualifications of the operators of these devices may also vary. All this together affects the ability to see or not see something. But sand will probably not be seen.
For the sake of interest, you will focus on various feature films in which there are scenes of ultrasound diagnostics of pregnant women. In some cases, you can see small ones even from the TV screen, while in other cases there will be only an incomprehensible bright spot.
Indeed, there is a diagnosis of urolithiasis, but there is no diagnosis of kidney sand. Crystals of acids precipitated in the kidney, the so-called. "sand", fine and washed out with urine flow from the body. They can be seen under a microscope in the urine. Ultrasound does not see them. But when they begin to cascade into small pebbles, they are then already noticed by USI