What Does The Kidney Ultrasound Report Suggest?

hi in my Ultra sound report it say right kidney shows few concreations. otherwise both kidneys are of normal size (RK=10.0.x3.4 cm, LK=10.2x4.7 cm) with normal cortical thickness & well preserved cortico medullary demarcation . No cyst, mass or hydronephrosis is seen

please help me is it something serious