Update on Imaging Features of Adult Pneumatosis Intestinalis

The term pneumatosis intestinalis (PI) means gas within the bowel wall.1–4 Pneumatosis intestinalis in the adult is an uncommon, important finding that may be associated with numerous clinical conditions, and ranges from benign to life-threatening (Table 1 on page 5).1–5 Although pneumatosis intestinalis can be seen on ultrasonography, MRI, and endoscopy, it usually is identified on plain abdominal radiographs or CT.6 Because its clinical relevance may be misinterpreted,4 it is important to remember that pneumatosis intestinalis is a sign, not a disease, and must be correlated with the patient's clinical condition. The terms pneumatosis cystoides intestinalis, intramural gas, cystic lymphopneumatosis, intestinal emphysema, intestinal gas cysts, bullous emphysema of the intestine, gas cysts of the intestine, peritoneal lymphopneumatosis, and pseudolipomatosis all have been used to describe pneumatosis intestinalis. However, most authors use the terms pneumatosis cystoides intestinalis to mean the benign colonic form of pneumatosis intestinalis and intramural gas for the life-threatening form, even though these terms have been used interchangeably.1–4 The use of multiple terms to describe pneumatosis intestinalis has caused considerable confusion in the literature. In this article, pneumatosis intestinalis means gas in the bowel wall, regardless of the cause or the patient's clinical condition.Table 1: Causes of Pneumatosis Intestinalis in the Adult: Benign and Life-Threatening Etiologies and Associations*