FIGURE 131.6 Probe positions for the abdominal FAST scan (A) Morison pouch, (B) splenorenal recess, (C) pelvic, and (D) subcostal cardiac Pitfalls For the Morison pouch and splenorenal recess views, the most common difficulty arises from rib shadows The probe can be rotated about 20 degrees such that its orientation is parallel to the course of the ribs above and below The probe can also be moved either anterior or posterior to optimize images It is also important to recognize the inferior vena cava and the gallbladder in the RUQ scan Both of these structures typically appear anechoic and can mimic free fluid in Morison pouch for the inexperienced sonographer The splenorenal recess is more difficult to visualize than Morison pouch because of the relative superior position of the left kidney and smaller spleen size Often, the probe is not positioned posterior or cephalad enough A frequent pitfall with the pelvic view is the inability to visualize the bladder Sometimes the bladder is empty (i.e., when a Foley catheter has been placed) More often, the probe is positioned too superior and should be slid and/or angled toward the feet Less commonly, the bladder is off of midline to the right or left There are several reasons why a sonographer may not view the heart during the cardiac examination First, the depth has not been adjusted from the abdominal scans The abdominal organs lie relatively closer to the skin than the heart does to