• Probe: Phased array/Curvilinear
  • Mode: FAST
  • Starting Depth: 10 cm


  • Morrison’s Pouch
  • Retrovesicular Space
    • Sagittal
    • Transverse
  • Perisplenic
  • Subcostal Cardiac
  • Lung sliding


  • MP (Liver and kidney junction):
    • Indicator to patients head, placed on R midaxillary line at inferior rib margin
    • Be sure to examine the caudal tip of the liver, as this is the area where fluid often accumulates first
    • Assess above the diaphragm to determine if pleural effusion present
  • PS (Between the spleen and the diaphragm):
    • Place probe at L posterior axillary line with indicator toward patient’s head
    • This view is often slightly more superior and posterior than MP
    • Assess above the diaphragm to determine if pleural effusion present
  • RV (Space above and slightly behind bladder):
    • Saggital view: Place probe just above pubic symphysis with indicator toward patient’s head, and rock handle up to look down, then fan side to side
    • Transverse view: Rotate indicator to patient’s R, then fan up and down
  • Cardiac: SC view or PSL view (See cardiac section for technique)
  • Lung Sliding:
    • Best to assess with linear probe: Change to Thoracic settings, place probe at mid clavicular line with indicator toward patients head.
    • Evaluate 2-3 intercostal spaces on most anterior chest for motion at plural line

Morison’s Pouch

Liver/Kidney interface

Perisplenic view

Spleen/Diaphragm interface

Retrovesicular Sagittal

Space above and behind bladder 

Retrovesicular Transverse


Lung Sliding

Look for movement on the pleural line Normal lung sliding

Morison’s Pouch free fluid

Fluid located between the liver and kidney

Perisplenic free fluid

Fluid between the spleen and diaphragm

Retrovesicular free fluid (Transverse view)

Retrovesicular free fluid (Sagittal view)

Pericardial Effusion


No movement is seen on the pleura

Incomplete view of Morison’s pouch

Fix → Scan to view the caudal tip of liver and inferior pole of the kidney

Missed free fluid posterior to the bladder

Fix → Fluid behind the bladder may appear isoechoic due to posterior acoustic enhancement. Adjust time gain compensation to decrease this artifact

Difficulty obtaining perisplenic view

Fix → Adjust probe to get a more posterior view of the LUQ

Free fluid incorrectly identified in thorax or abdomen

Fix → Identify the location of free fluid in relation to diaphragm. Fluid above the diaphragm is located in the thorax, while fluid below the diaphragm is located in the abdomen