The article by Moriwaki et al highlights the use of US for the diagnosis of IPFA in patients with acute abdominal pain or traumatic injury. The use of US for the diagnosis of IPFA was proposed as early as 1982,1 and numerous published studies2-4 have demonstrated its superiority to plain radiographs. Although CT remains the criterion standard in the diagnosis of IPFA, US has the advantages of being simple, rapid, inexpensive, and dynamic, and it can be used repeatedly as often as necessary without known harm to the patient.5