Can the Liver Be Visualized on RUQ Ultrasound?
Yes, the liver is routinely and reliably visualized on right upper quadrant (RUQ) ultrasound and serves as the primary sonographic window for evaluating multiple abdominal structures. 1
Primary Role of the Liver in RUQ Ultrasound
The liver functions as the essential acoustic window through which multiple structures are examined during RUQ ultrasound:
The liver in the epigastric region is most commonly used as a sonographic window to the heart during pericardial/subcostal views, requiring firm downward pressure to obtain views posterior to the sternum. 1
The liver provides superior visualization compared to other organs because of its size and acoustic properties—the spleen on the left side provides a much more limited window due to being substantially smaller. 1
Systematic scanning of the liver occurs through all tissue planes in at least two orthogonal directions as part of the standard RUQ examination protocol. 1
Specific Liver Evaluation During RUQ Ultrasound
RUQ ultrasound routinely assesses multiple hepatic features:
Ultrasound should specifically evaluate hepatic parenchymal abnormalities as part of the standard RUQ pain evaluation protocol recommended by the American College of Radiology. 2
The anterior gallbladder wall is measured where it is adjacent to hepatic parenchyma to accurately assess gallbladder wall thickness, demonstrating the liver's consistent visualization. 1
Adjacent liver parenchymal hyperemia is one of the earlier findings in acute cholecystitis and serves as a useful problem-solving tool, requiring direct visualization of the liver. 1
Ultrasound has high sensitivity (65-95%) and positive predictive value (98%) for detecting cirrhosis, including assessment of nodular liver surface, round edge, and hypoechoic nodules representing regenerative nodules. 3, 4, 5
Clinical Applications Requiring Liver Visualization
Multiple diagnostic pathways depend on direct liver visualization:
RUQ sonography is the first line of imaging in patients with signs and symptoms of hepatic, gallbladder, or biliary disease, establishing the liver as a primary target of examination. 6
High resolution ultrasound analysis of the ventral liver contour has 91.1% sensitivity and 93.5% specificity for diagnosing cirrhosis, demonstrating reliable liver surface visualization. 5
Modern liver ultrasonography provides anatomic, morphologic, and functional information about vascularity, stiffness, and various liver tissue properties, confirming comprehensive hepatic assessment capabilities. 7
Important Technical Considerations
Gain settings should be adjusted so that the diaphragm and renal sinus fat appear white, optimizing visualization of the liver and adjacent structures during the RUQ examination. 1
Angling inferiorly from the liver allows visualization of Morison's pouch and the inferior pole of the right kidney, though bowel gas may sometimes be interposed requiring a more posterior approach. 1
The liver is systematically examined during FAST examinations to evaluate the pleural space, subphrenic space, and Morison's pouch for free fluid in trauma patients. 1, 8