Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Bochdalek's hernia
- Radiologic Findings
- Chest radiographs show increased opacity at left lower lung zone with blunting of left costophrenic angle.
The left decubitus image shows shifting of the opacity.
Contrast-enhanced CT scans through the lower thorax demonstrate very low attenuating tissue in the left middle and lower pleural space.
There are multiple vessels of vertical direction in that tissue (mesenteric vessels).
Diaphragmatic defect is not demonstrated.
- Brief Review
- In infants, herniation through a persistent embryonic pleuroperitoneal hiatus is not only the most common form of diaphragmatic hernia but also by far the most serious.
Its incidence is 1 in 2,200 live births.
Seventy five to 90% occur on the left side.
When large, the hernias are associated with high death rate unless surgically corrected.
In adults, small Bochdalek's hernias are much more common than in infants and always unassociated with symptoms.
Their incidence increases with age, suggesting that they are acquired.
In one review of CT scans of the chest and abdomen performed in 940 adult patients, 60 Bochdalek's hernias were found in 52 patients, a prevalence of 6%.
On the chest radiography, Bochdalek's hernias can present as a focal bulge in the hemidiaphragm or as a mass adjacent to the posteromedial aspect of either hemidiaphragm.
Although the diagnosis can often be suspected by the typical location and by the lower than soft tissue density of the mass as a result of its fat content, the appearance can mimic that of pulmonary, mediastinal, or paravertebral masses.
The diagnosis is readily made on CT.
Occasionally, spiral CT with coronal or sagittal reformations may be required to demonstrate the defects.
- References
- 1. Gale ME: Bochdalek hernia: Prevalence and CT characteristics. Radiology 156:449, 1985.
2. De Martin WJ, House AJS: Partial Bochdalek's herniation: Computerized tomographic evaluation. Chest 77:702, 1980
3. Van Hise ML, Primack SL, Israel RS, Muller NL: CT in blunt chest trauma: Indications and limitations. RadioGraphics 18:1071, 1998
- Keywords
- Diaphragm, Congenital,