Perforation — Imaging Findings

Which radiological sign on plain abdominal X-ray is pathognomonic for hollow viscus perforation?

A 72-year-old woman from Kolkata with a history of diverticulosis presents with acute left lower abdominal pain, fever (39.1°C), and signs of peritonitis. Laboratory studies show WBC 16,000/μL and elevated CRP. CT abdomen with IV contrast reveals free air in the peritoneal cavity, a focal defect in the sigmoid colon wall, and localized purulent collection measuring 4 cm adjacent to the perforation site. What is the most appropriate next step in management based on these imaging findings?

A 58-year-old man from Delhi presents to the emergency department with acute onset severe epigastric pain radiating to the back, accompanied by vomiting. He has a history of peptic ulcer disease treated intermittently. On examination, he is febrile (38.5°C), tachycardic (110/min), and has severe epigastric tenderness with guarding. An upright chest X-ray is obtained. What is the most characteristic radiological finding that would support the diagnosis of perforated peptic ulcer?

A 42-year-old woman from Mumbai presents with acute severe diffuse abdominal pain, fever (39.2°C), and tachycardia (115/min). She reports a history of diverticular disease. On examination, she has rebound tenderness and guarding. A contrast-enhanced CT abdomen is performed. Which of the following CT findings would be most specific for colonic perforation secondary to diverticulitis?

A 38-year-old woman with a history of peptic ulcer disease presents with acute peritonitis. CT abdomen shows free air in the peritoneal cavity. Regarding the imaging characteristics of different types of hollow viscus perforation, all of the following statements are correct EXCEPT: