What does renal cortical echotexture mean?

Tissue density: Of kidney cortex. Cortex of kidneys contains nephrons, about 1 million/kideny. The area of kideney fuction, filtration ; reabsorbtion. Ultrasound is study using sound waves whuch either pass through tissue or bounce back. Echotexture is nil or black through water ; becomes progressively more white as tissus becomes more dense. Thus white for bone or stone. Dark/hypoechoic texture is usually better.