Kidney or renal ultrasound is a non-invasive imaging technique that is widely used due to its safety, accessibility, and real-time capabilities.
On this page:
Indications
Kidney ultrasound is commonly used in the evaluation and diagnosis of various renal disorders:
abdominal pain or flank pain
renal injury/failure
evaluation of congenital anomalies
detection and follow-up of cysts and tumors
post-operative evaluation, e.g. kidney transplant, partial nephrectomy
Normal findings
The following features are considered normal findings during a kidney ultrasound 2:
kidney size: normal adult kidneys measure around 9-13 cm in length, 4-6 cm in width, and 3-5 cm in thickness
kidney shape: bean-shaped with smooth contours
parenchyma: kidneys possess homogeneous echotexture with distinct corticomedullary differentiation
renal pelvis: central collecting system appears as hypoechoic structures with echogenic walls
Pathological findings
Common abnormal findings in a kidney ultrasound can result from various conditions, including 3:
renal cysts: well-defined, anechoic lesions with posterior acoustic enhancement
renal stones: echogenic foci with an acoustic shadow
hydronephrosis: dilated renal pelvis and calyces due to obstruction or reflux
renal masses: hypoechoic or hyperechoic solid lesions that may be malignant (e.g. renal cell carcinoma) or benign (e.g. angiomyolipoma)
infections: unilateral or bilateral enlargement with increased parenchymal echogenicity in acute pyelonephritis
congenital anomalies: abnormal kidney development, such as horseshoe kidney or renal agenesis
Practical points
kidney ultrasound has a high accuracy in diagnosing kidney cysts, stones, and hydronephrosis; however, further imaging modalities like CT or MRI may be required for definitive diagnosis or staging of diseases 4
additional diagnostic tests such as blood tests and urinalysis are often employed alongside kidney ultrasounds to provide a comprehensive evaluation of renal function and pathology
often, it is necessary to have patients take deep breaths and hold them during scanning to improve visualization of upper pole of kidneys as it pushes the organs away from the rib cage
Doppler imaging can be utilized to evaluate renal blood flow and detect any vascular abnormalities 4
Unable to process the form. Check for errors and try again.