Learning Objectives:

  1. Describe the indications and limitations of US of the kidneys and bladder

  2. Perform US to evaluate the urinary tract

  3. Identify relevant US anatomy including the renal cortex, renal pelvis, ureter, bladder, liver, spleen, and uterus or prostate

  4. Recognize the relevant findings and pitfalls when evaluating for hydronephrosis, renal calculi, renal masses, bladder volume, pregnancy, and Foley catheter evaluation


Indications:

  • Flank pain

  • Back pain

  • Abdominal pain

  • Hematuria

  • Acute Urinary Retention 

  • Acute Renal Failure/Acute Kidney Injury

Extended Indications:

  • Infection/abscess of the kidney

  • Gross bladder/prostate abnormalities

  • Foley cather placement/confirmation/evaluation

Required Views:

  • R/L kidney in transverse

  • R/L kidney in sagittal

  • Bladder in transverse

  • Bladder in sagittal 

  • Post void residual if applicable

ANATOMY:

Figure 1. Normal renal anatomy

How to Scan:

ACEP Sonoguide: Renal Ultrasound

Five Minute Sono: Hydronephrosis 

Five Minute Sono: Bladder Volume Measurement

POCUS 101: Renal Ultrasound Made Easy

Tips/Tricks/Pitfalls:

  • Hydronephrosis is commonly seen in the 3rd trimester of pregnancy

  • Hydronephrosis can be masked by dehydration - a fluid bolus can make assessment easier

  • Mimics of hydronephrosis - vasculature and prominent medullary pyramids 

    • Use color doppler to distinguish vasculature from hydronephrosis

  • Use color doppler over the ureteral jets to check for obstruction 

  • Consider scanning the aorta in older patients with flank pain

Pathology:

  • Hydronephrosis

  • Stones

  • UVJ obstruction with twinkling artifact 

  • Cysts

  • Renal masses

Key Literature:

  1. Gaspari & Horst, Emergency Ultrasound and Urinalysis for Flank Pain

  2. Smith-Bindman et al, Ultrasound vs CT for Suspected Nephrolithiasis *

  3. Pathan, et al, EM Physician Identification and Grading of Hydronephrosis Compared with Radiologists

Additional Resources:

Introduction to Bedside Ultrasound iBook Volume 1: Chapter 6: Renal 

The POCUS Atlas: Renal/GU

ACEP Emergency Ultrasound Imaging Criteria Compendium  Pages 23-28

AEUS Lecture by Peregrine Dalziel

Renal Ultrasound Lecture by Geoff Hayden

Author: Victoria Gonzalez, MD  

Peer editing by: Victoria Gonzalez, MD

Figure 2. Normal renal US.