Kidney ultrasound – what is important for a urologist?

Kidney ultrasound is one of the basic procedures in the practice of a urologist. Apart from the location and the size, description of renal morphology should contain the thickness of the anterior lip parenchyma in a transverse section and the location of possible narrowings. Uneven outline of the kidney is a sign of past inflammatory conditions. In the case of the pelvicalyceal system dilation, it is advised to specify the dimensions of the pelvis and calyces. Convex shape of the calyces proves elevated pressure within the pelvicalyceal system. Hydronephrosis is present when urinary retention has led to thinning the renal parenchyma. In each case, one should identify the reason for urinary retention in the upper urinary tract. Urinary retention on both sides requires one to exclude urinary bladder tumor, it may also be caused by a benign prostatic hyperplasia. Ultrasound examination is a sensitive method of renal stones detection, regardless of their chemical composition. Cyst description in an ultrasound image should cover its morphological features, differentiating between the so-called simple or complex cysts. In the case of a solid lesion, ultrasound makes it possible to detect parenchymal lesions usually starting with the size of 2–2.5 cm. It enables one to particularly diagnose angiomyolipomas. As regards the remaining parenchymal lesions, differentiation of the lesion nature is impossible. In some cases of angiomyolipoma, when it contains bleeding areas present and when it is deficient in adipose tissue, it resembles adenocarcinoma. It is necessary that the description includes the exact location, especially the dimensions and relation of the tumor to the renal sinus. In the case of larger lesions, respiratory motion of the kidney, the condition of the adrenal gland and the presence of enlarged lymph nodes should be controlled. Additionally, one should evaluate the renal vein and inferior vena cava in terms of a neoplastic plug presence.