The mediastinum--is it wide?
C E Gleeson1, R L Spedding, L A Harding
1Accident and Emergency, Warrington Hospital NHS Trust.
Emergency Medicine Journal : EMJ
|May 17, 2001
Summary
The 8 cm upper limit for normal mediastinal width is outdated for modern trauma care. New upper limits are defined based on current radiographic techniques to accurately assess mediastinal width in trauma patients.
Area of Science:
- Radiology
- Trauma Imaging
- Thoracic Medicine
Background:
- The traditional 8 cm upper limit for mediastinal width was established in the 1970s.
- Modern trauma care and imaging techniques may differ significantly from those used previously.
Purpose of the Study:
- To re-evaluate the applicability of the 8 cm upper limit for mediastinal width in contemporary trauma settings.
- To establish updated normal upper limits for mediastinal width on supine chest radiographs.
Main Methods:
- Retrospective review of chest computed tomography (CT) scans to measure mediastinal width and position.
- Analysis of radiographic techniques to determine mediastinal magnification factors.
Main Results:
- The mean mediastinal width was found to be 6.31 cm.
- Standard radiography resulted in magnification, yielding mediastinal widths of 8.93-10.07 cm.
- Adjustments in radiographic technique reduced magnification, with measured widths between 7.31-7.92 cm.
Conclusions:
- The 1970s-era 8 cm upper limit is no longer applicable in modern trauma imaging.
- Modifications in X-ray cassette positioning and source-to-patient distance can decrease mediastinal magnification.
- New upper limits for mediastinal width are proposed, tailored to various trauma imaging techniques.
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