The FAST examination is a structured and systematic investigation to confirm or exclude the presence of free fluid in the pericardium and the abdomen

Free fluid is seen as homogeneous anechoic (black) “masses” in locations where fluid is not normally found

By obtaining sonographic imaging in a trauma patient and looking in the right locations whilst comparing with normal images it is possible to either confirm or exclude the presence of free fluid in the peritoneal and pericardial cavities

This introduction to FAST will teach you how to identify free fluid in the RUQ region

The right upper quadrant (RUQ) is examined as described in the module about sonoanatomy

This includes:

– Finding the liver
– Finding the diaphragm
– Finding the free margin of the liver – very sensitive for intraabdominal fluid/blood collection
– Finding the subdiaphragmatic space
– Finding the hepatorenal recess – the Morison’s pouch

Look for free fluid in the pleural cavity above the diaphragm (part of the eFAST examination)

Intraperitoneal fluid appears as a black hypoechoic or anechoic stripe

The video shows a recording of a FAST examination in the RUQ from a trauma patient with fluid in the abdomen

A normal RUQ recording is shown for comparison

The FAST examination of the transverse P view includes:

– Placing the patient in the supine position (as for all the scanning positions)
– Placing the transducer in the midline of the abdomen
– Assuring that the orientation marker on the transducer is directed towards the patient’s right side
– Assuring that the orientation indicator on the screen is on the left side
– Adjusting (aligning, rotating and tilting) the transducer (ART) until the urinary bladder is visualised
– Identifying the urinary bladder
– Identifying the rectum behind the urinary bladder

The pelvic view is obtained by placing the transducer in the mid abdomen, just above the pubic symphysis

Two views are used:
– The longitudinal view
– The transverse view

The orientation marker (OM) on the transducer should be directed toward the head in a the longitudinal (sagittal) plane, and directed to the right in the transverse (horizontal) plane

Notice the location of the bladder in the abdomen and the orientation of the ultrasound sector beam (the scanning plane)

The target view is an image of the target structures

The diaphragm is displayed on the left side of the screen, when the OM is correctly pointing towards the head in the coronal plane with the OI on the left side of the screen

The structures identified with the LUQ view:

– Diaphragm – white hyperechoic convex line above the homogenous spleen tissue
– Spleen – observe the more homogenous texture without vessels and ducts (compared to the liver)
– The left kidney – characteristic “kidney bean form” with hyperechoic calyces and kidney pelvis
– The splenorenal recess
– The subdiaphragmatic space between the diaphragm and the spleen

The left upper quadrant view is obtained in the same way as right upper quadrant view

Be aware that a slight rotation on the transducer in order to avoid rib shadowing should be done with a clockwise rotation as opposed to the counter-clockwise rotation in the right upper quadrant view

The transverse pelvic view is obtained by placing the transducer in the midline at the inferior aspect of the abdomen, just above the pubic symphysis

The orientation marker (OM – blue dot) on the transducer is directed towards the right side of the patient’s body in a transverse plane; the OM corresponds to the orientation indicator (OI – blue dot) on the left side of the screen

The left side of the ultrasound sector (red) corresponds to the left side (also red) of the screen, and the right side of the ultrasound sector (green) to the right side of the screen (also green)

By aligning and tilting the transducer, the urinary bladder can be visualised

The left-upper-quadrant (LUQ) view is obtained by placing the transducer in the left posterior axillary line at the inferior aspect of the thoracic cage

The orientation marker (OM – blue dot) on the transducer is directed towards the head in the coronal plane; the OM corresponds to the orientation indicator (OI – blue dot) on the left side of the screen

The upper side of the ultrasound sector (red) corresponds to the left side (also red) of the screen, and the lower side (green) to the right side of the screen (also green)

By adjusting the transducer (align, rotate and tilt), the diaphragm, the spleen and the left kidney can be visualised

The ribs cannot be penetrated by the ultrasound beam and placing the transducer on a rib will produce a dark anechoic shadow and the underlying structures are not visible; it is important to place the transducer between the ribs

The right-upper-quadrant (RUQ) -view is obtained by aligning the transducer along the right posterior axillary line at the inferior part of the thoracic cage

The orientation marker (OM) on the transducer should be directed toward the head in the coronal plane

The orientation indicator (OI) on the screen is on the left side of the ultrasound screen

By adjusting the transducer (align, rotate and tilt) the diaphragm, the liver and the right kidney can be visualised

The ribs cannot be penetrated by the ultrasound beam, and placing the transducer on top of a rib will produce a dark anechoic shadow and no underlying structures are visualised

For that reason it is important to place the transducer between the ribs