Bedside Renal Ultrasonography: Limited, Goal-Directed

Confirmation of the diagnosis of obstructive uropathy in patients suspected of ureteral colic

Abdominal or flank pain

Hematuria

Groin pain

Acute urinary retention

Known or suspected acute renal failure

Laboratory evidence of renal failure

Oliguria or anuria

Painless hematuria or proteinuria

Suspected renal abscess

Infected urine with fever and abdominal or flank pain

Suspected or known abdominal trauma

CONTRAINDICATIONS

None

RISKS/CONSENT ISSUES

Allergy to the ultrasonography gel

LANDMARKS

The right kidney is usually located inferior and posterior to the liver

The left kidney is located inferior to the spleen

The bladder should be imaged in the suprapubic region

TECHNIQUE

A 3.5-MHz probe is commonly suitable for most adults, although a 5.0-MHz probe can be used in patients with a thinner body habitus and in children

The Right Kidney

With the patient supine, start at the midaxillary line at the level of the lower ribs holding the probe in the longitudinal axis or slightly oblique and scan laterally until the sagittal view of the hepatorenal space (Morison pouch) and the right kidney are visible

Rotate the probe 90 degrees to obtain a transverse image of the kidney. Move the probe superiorly and inferiorly to locate the renal hilum and visualize the full extent of the parenchyma (FIGURE 40.1).

The Left Kidney

The left kidney is most easily located by placing the probe hand against the bed while scanning the left flank at the posterior axillary line at the level of the lower ribs

Rotate the probe 90 degrees to obtain a transverse view of the left kidney

The Bladder

The bladder is best imaged when it is moderately filled at the time of examination

Place the probe suprapubically in the transverse plane. Angle the probe toward the patient’s feet. Color Doppler techniques can be used over the trigone area to verify the presence of ureteral flow jets indicating urine flow into the bladder.