[Ultrasound differential diagnosis in renal parenchymal disease].

Ultrasound examination is an integral part of nephrologic differential diagnosis in renal parenchymal disease. A systematic recognition of kidney position, size, shape, contour, structural design and renal perfusion lead together with clinical findings in correct direction of differential diagnosis. Unspecific findings exist in many acute renal diseases (large kidney with prominent pyramids and echogenic cortex). In chronic renal diseases the sonomorphology of chronic glomerulonephritis, pyelonephritis or analgesic nephropathy are more specific. Diagnosis of renal arterial stenosis is almost possible with duplex ultrasonography. Disturbances of kidney perfusion (infection, infarction) are diagnosed with echocontrast-ultrasonography.