Does kidney stone B need to hold urine

Generally, when doing B ultrasound of kidney stones, the doctor in the B ultrasound room does not require urine retention. Because kidney stones in B ultrasound reflect a strong echo of an imaging shape, from B ultrasound above generally see kidney stones is relatively clear. But if there is no urine accumulation in the kidney, such as renal pelvis and renal calyx, sometimes it is not easy to compare, the diagnosis of kidney stones will lead to certain errors. Therefore, the patient is required to hold urine. When there is more urine accumulated in the bladder, the urine secreted from the kidneys will stop flowing into the bladder, so that there will be urine accumulation in the renal pelvis or ureter. At this time, when B-ultrasound is used to see kidney stones, after urine contrast, it can clearly show the specific shape, size, position and so on.