TY - CHAP M1 - Book, Section TI - Imaging Studies of the Kidney A1 - Dirkx, Tonja C. A1 - Woodell, Tyler A2 - Papadakis, Maxine A. A2 - McPhee, Stephen J. A2 - Rabow, Michael W. Y1 - 2020 N1 - T2 - Current Medical Diagnosis and Treatment 2020 AB - Ultrasonography can characterize the thickness and echogenicity of the renal cortex, medulla, and pyramids and identify a distended urine collecting system. Kidney size can be measured; normal kidney size, which can vary depending on age and size of adults, is usually 9–12 cm in length. A kidney less than 9 cm in length in an adult suggests (but does not confirm) significant, irreversible kidney disease. A difference in size of more than 1.5 cm between the two kidneys may be observed in unilateral kidney disease. Kidney ultrasound is also performed to assess for obstruction and hydronephrosis (eFigure 22–2), to characterize kidney mass lesions, to screen for autosomal dominant polycystic kidney disease (see Figure 22–6), to evaluate the perirenal space, to localize the kidney for a percutaneous invasive procedure, and to assess postvoiding residual urine volume of the bladder. Assessing kidneys in markedly obese patients can be difficult due to body habitus; a CT scan may be required. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2022/05/16 UR - accessmedicine.mhmedical.com/content.aspx?aid=1166170486 ER -