Final answer:
In patients with gallstones demonstrated with sonography but no fever or elevated white blood cell count, CT scan of the abdomen is the highly recommended additional imaging procedure.
Step-by-step explanation:
In patients who have gallstones demonstrated with sonography but do not have fever or an elevated white blood cell count, the highly recommended additional imaging procedure is CT of the abdomen (With or without contrast).
CT scan with contrast dye can help assess the health of the pancreas and identify complications of pancreatic disease such as fluid around the pancreas, abscess, or pancreatic pseudocyst. It is a useful diagnostic tool in this scenario.
Neither nuclear medicine cholescintigraphy nor MRI of the abdomen (with or without contrast) are highly recommended in this specific case.