Fig. 13From: The anatomical compartments and their connections as demonstrated by ectopic airLocal causes of extraperitoneal pelvic emphysema. (a) Sigmoid perforation (necrotising acute colitis probably due to fecaloma) in a 75-year-old female. Unenhanced-CT scans of pelvis shows gas pockets in the sigmoid mesocolon, extending superiorly to retroperitoneum through the combined interfascial plane. (b) Fournier gangrene in a 67-year-old diabetic man. Contrast-enhanced CT scan shows fluid and air pockets tracking in the corpora cavernosa, extending anteriorly to an enlarged scrotal sac containing gas and cranially to the ischiorectal fossa and subcutaneous tissueBack to article page