Gastric Rupture on Positive RUQ FAST Exam Bike vs Car. Bicyclist hits anterior torso on mailbox. What is source of fluid in this positive Perihepatic window.? Source of fluid-Perforated viscus (gastric rupture). Note the presence of free air within fluid. Always look for sonographic signs of air in the wrong place. Dr. Robert Jones @RJonesSonoEM #Gastric #Rupture #RUQ #FAST #Exam #Positive #Abdominal #POCUS #clinical #ultrasound #Liver #Trauma