Hello Thanks for query . Kidney has two parts cortex and Medulla Cortex deals with the filtration of blood through kidney and production of urine along with excretion of waste products of protein metabolism (Urea and Creatinine )where as medulla deals with blood flow to kidneys . In normal kidney during ultrasound scanning signal intensity of renal cortex is higher than that of medulla .This differentiation between signal intensity is reflected and well defined in ultrasound very clearly .This differentiation is reduced in any renal paranchymal disease making it more echogenic than normal resulting into loss of differentiation between cortex and medulla . Since your Ultrasound report mentions cortex to be more echogenic and raised creatinine suggest that you have early Renal Paranchymal disease . Dr.patil.