A 65-year-old man presents to the emergency department with sudden-onset severe upper abdominal pain. The patient reports that the pain began abruptly 8 hours ago while resting. It is severe, constant, and localized to the upper abdomen but radiates to his right shoulder. He also feels nauseous but has not vomited. He has a history of intermittent epigastric pain for the past year, often relieved by over-the-counter antacids. Recently, he started taking ibuprofen daily for knee pain. Past Medical History: •Peptic ulcer disease (diagnosed 2 years ago). •Hypertension, managed with lisinopril. Medications: •Ibuprofen, 400 mg twice daily (started 1 month ago). •Lisinopril, 10 mg daily. Social History: •Smoker: 20 pack-year history. •Occasional alcohol use. Physical Examination: •Vital signs: BP 90/60 mmHg, HR 115 bpm, Temp 99.8°F, RR 22/min. •General: Appears distressed and in significant pain. •Abdomen: •Rigid with diffuse tenderness, particularly in the epigastric region. •Positive rebound tenderness and guarding. •Absent bowel sounds. Laboratory Findings: •White blood cell count: 18,000/mm³ (elevated). •Hemoglobin: 12.8 g/dL (normal). •Serum amylase/lipase: Normal. •Liver function tests: Normal. Which of the following imaging findings would confirm the diagnosis of a perforated peptic ulcer?
