SUBJECT: Ultrasound for Inguinal Hernia
SECTION: Radiology Ultrasound
ORIGINATOR: Jody Riherd, MD
REVIEW DATE: September 13, 2013
Role of US
- To confirm the presence of a hernia
- To distinguish between inguinal vs femoral hernia
- If inguinal, to subclassify direct vs indirect
- To identify the content of the hernia (omental fat +/- bowel)
- Reducible vs non-reducible
- Is it symptomatic (focally tender or not)
- Identify alternative pathology
- Use a linear transducer 7-12MHz
Begin supine. If no hernia detected, reexamine erect.
To find the internal inguinal canal: Start from down at the common femoral vessels and work your way in a transverse plane superiorly until you reach the level above where the inferior epigastric vessels join the ext. iliac vein and artery.
- Turn the probe to go along the plane of the inguinal canal/inguinal ligament.
- Watch for movement of omentum/or bowel within the canal or medial to it.
- If there is sliding down the canal this is usually an indirect hernia as it originates lateral to the epigastric vessels.
- If there is medial movement to the IEV then this is a direct hernia and it does not usually communicate with the inguinal canal.
- Check if the omentum/bowel is free to move back within the peritoneum (reducible hernia) or does it gets stuck (strangulated).
To find a femoral hernia: Scan transversely over common femoral vessels and look medial to the vessels when the patient strains.
- The lump will present lateral and caudal to the pubic ramus.
- With a hernia present, the common femoral vein will not expand as it normally should. As it pushes through the femoral canal, the hernia will compress the vein.
- Inguinal canal at rest and straining in 2 planes (Long axis is along plane of inguinal ligament. Transverse is perpendicular to the inguinal ligament)
- Femoral canal at rest and straining in 2 planes (Long axis along plane of femoral vein, transverse to femoral vein)
- Cine if positive for hernia
- Contralateral groin images are not required to document, but evaluate and document images if there are questions or confusion with the ipsilateral side