FAST stands for Focused Assessment with Sonography for Trauma.

Primary Indication

  • Hypotension after trauma
  • Free fluid in the thorax or abdomen is assumed to be blood
  • Positive FAST = fluid found in one or more windows
  • Indication for operation
  • Performed in abdominal presets/exam type
  • Most systems have FAST exam type


  • Phased Array in abdominal/FAST presets
  • Curvilinear in abdominal/FAST presets

FAST and e-FAST Windows (Figures 1, 2)

Right Upper Quadrant (RUQ)

  • Evaluate the hepatorenal recess (Morrison’s Pouch) and lower right thorax
  • Right anterior axillary line
  • Indicator aimed up
  • Find potential space between the liver and kidney (Figure 2)
  • Look for a black stripe of fluid between the liver and kidney

Left Upper Quadrant (LUQ)

  • Evaluate the subphrenic space and splenorenal recess and lower left thorax
  • Left anterior axillary line
  • Indicator aimed up
  • Find potential space between the spleen and kidney
  • Look for black stripe of fluid
  • Make sure to look above the spleen (Video 1)


  • Evaluate the rectovesical pouch in male patients and rectouterine pouch of Douglas in female patients
  • Transverse above the super pubic region
  • Indicator to patient’s right
  • Look for fluid around the bladder (Video 2)

Cardiac (subxiphoid view):

  • Evaluate the pericardium for effusion (tamponade) and evaluate for right heart strain (PE)
  • 2 cm below the xiphoid
  • Indicator to the patients right
  • Angle under the xiphoid and then tilt up
  • See the 4-chambers of the heart
  • Look for fluid between the RV and the liver (Video 4)


  • From the RUQ fan into the chest to look for hemothorax
  • From the LUQ fan into the chest to look for hemothorax
  • Look to the right and left of the sternum for lung sliding. Lack of sliding indicates possible pneumothorax (Video 4)

Figures and Clips

Figure 1 - Normal FAST in RUQ

Figure 2 - Positive FAST in RUQ

Clip 1 - Positive FAST in LUQ

Clip 2 - Positive FAST in Pelvis

Clip 3 - Positive FAST (Pneumothorax)

Clip 4 - Positive FAST in subxiphoid area (pericardiac fluid)


Richards, J. R., and J. P. McGahan. “Focused Assessment with Sonography in Trauma (FAST) in 2017: What Radiologists Can Learn.” Radiology 283.1 (2017): 30.