This is a case-control study. The investigators obtained data from participants who were older than 20 years old and received renal sonography examination in the emergency department of National Taiwan University Hospital. The investigators examined the participants' kidneys by recording the kidney size, cortical thickness, possible lesions and elasticity by shear-wave elastography. These data combined with the participants' medical history and renal function revealed by blood examination will be analyzed. This study was designed to determine the correlation between renal cortical elasticity and chronic kidney disease.
