What anatomical variant may be present as a normal finding in the liver during an ultrasound?

Reidel's lobe is an anatomical variant associated with the liver that can appear as a normal finding during an ultrasound. It refers to a tongue-like extension or lobe of the liver that can project downward, typically situated at the right lobe's anterior or inferior border. This variant is often asymptomatic and is considered a normal anatomical variant rather than a pathological condition.

During ultrasonography, recognizing Reidel's lobe is important because it can be mistaken for a pathological mass or other abnormalities if not properly identified. Its presence underscores the variability in human anatomy and the significance of correlating echogenicity and structural appearance with normal variants. This understanding helps sonographers avoid unnecessary concerns or additional imaging in patients who have this anatomical feature.

Other options, while potentially interesting variants, do not pertain directly to the liver in the same manner. An accessory spleen, a third kidney, or a duplicated gallbladder are anatomical variations associated with the spleen, kidneys, and gallbladder respectively, and are not typically seen in the context of liver anatomy during ultrasound assessment.