Renal (Hydronephrosis)

1. 1

   Position patient supine or slightly oblique. Use curvilinear probe.

2. 2

   Right kidney: probe in right mid-axillary line, 9th–11th ICS, marker toward head. Use liver as acoustic window.

3. 3

   Left kidney: probe in left posterior axillary line. Ask patient to take a deep breath to bring kidney into view.

4. 4

   Scan each kidney in full longitudinal sweep, then rotate to transverse. Measure length (longitudinal), width, and AP.

5. 5

   Assess renal pelvis and calyces: anechoic separation = hydronephrosis. Grade mild (pelvis only), moderate (calyces), severe (cortical thinning).

6. 6

   Look for stones: hyperechoic foci with posterior shadowing, often at the UPJ or ureter.

7. 7

   Scan bladder transverse and sagittal: assess for distal ureteral jets with color Doppler and post-void residual.

• Right kidney (longitudinal + transverse)
• Left kidney (longitudinal + transverse)
• Bladder (transverse + sagittal)

• Hydronephrosis grade
• Kidney size
• Cortical thickness
• Stones
• Perinephric fluid

• Renal sinus fat vs. hydronephrosis
• Full bladder causes false hydronephrosis — rescan post-void

Grade: Mild = renal pelvis only; Moderate = calyces; Severe = cortical thinning.