• Pneumoperitoneum
• Pneumoperitoneum- Radiographic Techniques
• Neonatal Abdominal Pathology
• The Lateral Decubitus Abdominal Plain Film

	This 39 year old male was admitted with inflammatory bowel disease. He was noted to have basal crackles on auscultation and was referred for chest radiography.
	There is a subtle lucency under the right hemidiaphragm which could represent air under the diaphragm.
	The lateral projection chest image demonstrated air around the liver.
	Free gas was present under the right hemidiaphragm (arrowed). Contrary to popular opinion, the most sensitive projection for pneumoperitoneum is an erect lateral chest projection centred on the diaphragm.