Computed tomography of retrocrural spaces: normal, anatomic variants, and pathologic conditions

Our plain-English summary of Computed tomography of retrocrural spaces: normal, anatomic variants, and pathologic conditions, by M.S. Shin, L.L. Berland (AJR. American Journal of Roentgenology, 1985).

The study

• Authors: M.S. Shin, L.L. Berland
• Journal: AJR. American Journal of Roentgenology
• Published: 1985;145(1):81-6
• Cited by: 17 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

This pictorial essay described the computed tomography (CT) appearance of the retrocrural space, the area behind the diaphragmatic crura. It covered normal anatomy, anatomic variants and disease. The authors drew on thoracic and abdominal CT scans of about 18,000 cases at the University of Alabama between 1978 and 1983, together with other radiologic studies and clinical data. The scans were obtained on GE 8800 or Philips Tomoscan 310 machines, generally at 10-mm intervals, usually with intravenous contrast given as a bolus. The essay described the normal crura and the structures within the space, including the aorta, azygos veins, lymph nodes, cisterna chyli and thoracic duct. Normal variants could mimic disease: lobulated or large crura could simulate enlarged lymph nodes, and a normal lung tip, seen in about 3% of patients, could mimic retroperitoneal air. Illustrated diseases included lymph node enlargement from noncaseating granulomata, fluid from acute pancreatitis, metastatic colon cancer, and clinically unsuspected metastatic mesothelioma. Others were bleeding after a vertebral compression fracture, steroid-induced fat deposits, varices with liver cirrhosis or superior vena caval obstruction by seminoma, and a ruptured aortic aneurysm. The authors noted that pleural mesothelioma may occasionally extend into the retrocrural space and that CT can help detect such spread and stage the disease. They concluded that radiologists should be familiar with the normal anatomy, variants and diseases of this small region.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This was a pictorial essay, not a study measuring disease rates. The authors, from the radiology department at the University of Alabama in Birmingham, wrote that chest and abdominal CT scans were obtained there in about 18,000 cases from 1978 to 1983. They used scans from that period to illustrate the retrocrural space, a small area behind the diaphragm's muscular bands (the crura), in front of the spine. They described its normal anatomy, normal variations that can mimic disease, and example cases. About 3% of patients showed a normal lung tip in this space, which can look like abnormal air. Example cases included enlarged lymph nodes, pancreatitis fluid, spread of colon cancer, bleeding after a spine fracture, fat deposits, enlarged veins, and a ruptured aortic aneurysm. In one patient with mesothelioma, its spread into this space had not been suspected clinically. The authors wrote that pleural mesothelioma may occasionally extend into the peritoneal cavity and retrocrural spaces, and that CT is ideal for detecting such spread and helping stage the disease. The article did not mention asbestos.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Pictorial essay (illustrated review of CT images with example cases), not a study of rates or causes
• Who was studied: Thoracic and abdominal CT scans were obtained at the University of Alabama in about 18,000 cases from 1978 to 1983. Individual illustrative patients were shown. The article did not say how many of these cases were reviewed for the essay or how many patients had each condition.
• Exposure: No exposure was studied. Asbestos and fiber types were not mentioned. The article concerned the CT appearance of the retrocrural space.
• Main results:
  • About 3% of patients examined by CT showed a normal lung tip in the retrocrural space. The authors said this can mimic free air or gas from abscesses.
  • One illustrated patient had clinically unsuspected spread (metastasis) of mesothelioma to the retrocrural space, with bulging of the crura.
  • The figure caption for this mesothelioma case described pleural mesothelioma on the right directly invading the right crus.
  • In the discussion, the authors wrote that pleural mesothelioma may occasionally extend into the peritoneal cavity and the retroperitoneal and retrocrural spaces.
  • Other example cases included enlarged retrocrural lymph nodes from noncaseating granulomata, which were confirmed by biopsy.
  • Another example case was retrocrural bleeding from a compression fracture of a thoracic vertebra (T12), with attenuation of 20 to 30 H.
  • A further example case was a 60-year-old woman whose ruptured aortic aneurysm caused massive retrocrural hemorrhage. She died.
• The authors' conclusion: The authors concluded that, although the retrocrural space is small, many important pathologic conditions may be found within it, and that radiologists should be familiar with its normal anatomy, variants and diseases. Regarding pleural mesothelioma, they wrote that CT is ideal for early detection of its extensions and as an aid in staging the disease for therapy.

Topics

Medical terms in this study, explained in our Lexicon: CT Scan, Colorectal Cancer, Mesothelioma, Pleural Mesothelioma.

Related studies

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• Computed tomography in pulmonary asbestosis — D. Katz, L. Kreel (1979)
• Lung function not affected by asbestos exposure in workers with normal Computed Tomography scan — C. Schikowsky, M.K. Felten, et al. (2017)
• Thoracic shaping technique to avoid residual space after extended pleurectomy/decortication — S. Bölükbas, M. Eberlein, et al. (2013)
• Commentary to the article lung function not affected by asbestos exposure in workers with normal Computed Tomography scan, by Schikowsky, Felten, et al., 2017 — X. Baur, B. Terracini, et al. (2018)

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