retroperitoneal gas
The
anatomical compartments and their connections as demonstrated by ectopic air. Imaging subcutaneous emphysema. Duodenal perforation complicating ERCP in a 75-year old woman. a Chest conventional PA radiography shows linear lucent areas in subcutaneous and chest wall tissues. b, c Contrast-enhanced CT scan at the level of the kidneys. The “lung window” (a) easily depicts the presence of air dissecting the retroperitoneum as well as extending to the abdominal wall; the “soft tissue window” (b) accurately localizes ectopic air/gas in the different planes of retroperitoneum, and in the abdominal muscular and subcutaneous tissue. Air is also seen in the contrast filled gallbladder (red star) with an air-fluid level (ERCP-related findings) and transverse colon (blue triangle)
The
anatomical compartments and their connections as demonstrated by ectopic air. Duodenal perforation complicating ERCP in a 75-year-old woman. Sagittal reformatted (a) and axial (b) contrast-enhanced CT scan demonstrates the right superior extension of the interfascial plane. The multilaminated retroperitoneum is open towards the upper abdominal extraperitoneal space: the bare area of the liver, and communicates with liver hilum through the subperitoneal space of the hepatoduodenal ligament
Pneumoretroperitoneum
• Pneumoperitoneum and pneumoretroperitoneum - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Pneumoretroperitoneum - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Pneumoretroperitoneum - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Pneumoretroperitoneum - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Pneumoretroperitoneum - Ganzer Fall bei Radiopaedia
Hydropneumothorax
• Hydropneumothorax, pneumomediastinum, pneumoperitoneum and pneumoretroperitoneum - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Pneumoretroperitoneum - post ERCP perforation - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Emphysematous pyelonephritis - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Pneumoretroperitoneum - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Bowel perforation at ERCP - Ganzer Fall bei Radiopaedia
Pneumoretroperitoneum
• Perforated diverticulitis with free gas in peritoneal and retroperitoneal spaces - Ganzer Fall bei Radiopaedia
Pneumoperitoneum
• Perforated diverticulitis with free gas in peritoneal and retroperitoneal spaces - Ganzer Fall bei Radiopaedia
Gastrointestinal
perforation: clinical and MDCT clues for identification of aetiology. 82-year-old oncology patient presenting with spontaneous perforation of the ascending colon. Coronal oblique contrast-enhanced image (modified soft tissue window) depicts pneumatosis intestinalis (arrow) and free gas extending to the right pararenal space and to the bare area of the liver (arrowheads) consistent with retropneumoperitoneum. A left retroperitoneal haemorrhage is noted as an independent finding (*)
Teenager post
cardiac arrest 1 day ago who had pneumomediastinum on an immediate post resuscitation CXR. AXR (above) shows air outlining the right kidney and the inferior part of the liver. AXR (below) shows air outlining the ascending and descending colon and bladder.The diagnosis was pneumoretroperitoneum.
Pneumoretroperitoneum is by definition presence of gas within the retroperitoneal space.
Pathology
Pneumoretroperitoneum is always abnormal and has a relatively small differential:
- perforated retroperitoneal hollow viscus
- duodenum
- peptic ulcer disease
- blunt or penetrating abdominal trauma
- endoscopy +/- biopsy (rare)
- ERCP: especially when a sphincterotomy is performed; incidence 0.5-2%
- ascending/descending colon
- colorectal carcinoma (CRC)
- diverticulitis
- endoscopy +/- biopsy
- ischemic colitis
- rectum
- surgery, e.g. transanal excision of rectal carcinoma
- foreign body insertion
- endoscopy
- trauma
- rarely an intraperitoneal hollow viscus can perforate into the intramesenteric space and then track air to the retroperitoneal spaces
- duodenum
- residual air from retroperitoneal surgery
- urological/adrenal
- spinal (anterolateral approach)
If localized, and especially in the presence of an air-fluid level, a retroperitoneal abscess should be suspected.
Radiographic features
Pneumoretroperitoneum is best appreciated by CT, however, can also be detected by plain abdominal radiograph and even by transabdominal ultrasound. Generally, the air is most commonly seen surrounding the kidneys in the right and left upper quadrants of the abdomen . There may also be a loss of the normal psoas muscle shadow .
Ultrasound
Interfaces between free air and soft tissues appear as echogenic lines with posterior reverberation artifacts and the obscuration of far-field structures. In pneumoretroperitoneum air will collect around the following structures :
- right kidney
- referred to as the veiled right kidney sign
- will not change appearance with patient re-positioning, as opposed to the free air in pneumoperitoneum
- referred to as the veiled right kidney sign
- great vessels
- the disappearance of the retroperitoneal inferior vena cava and abdominal aorta
- head of the pancreas
- gallbladder
- retroperitoneal air will collect posteriorly
- duodenum
Differential diagnosis
On plain radiography, the differential is that of gas in other spaces which also projects over the abdomen. It thus includes:
CT has little difficulty in distinguishing these.
See also
Siehe auch:
- Pneumoperitoneum
- Divertikulitis
- Duodenum
- Retroperitoneum
- Fremdkörper
- Kolorektales Karzinom
- Pseudopneumoperitoneum
- Weichteilemphysem
- abnormales Gas im Abdomen
- Rektumkarzinom
- Pneumoretroperitoneum nach ERCP mit Perforation
- ischeamic colitis
und weiter:
Assoziationen und Differentialdiagnosen zu freie retroperitoneale Luft:
