Der Radiologe
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After perforating eye injury the retention of a foreign body in the orbits has to be excluded. Wooden foreign bodies mostly have negative density on CT, which increases later as a result of granulomatous changes. On MRI, pieces of wood appear with low signal intensity, and only in some cases is a collar-shaped structure recognizable, allowing differentiation from gas. Soon after orbital trauma with splinters of wood, therefore CT allows better differentiation of pieces of wood from intraorbital gas by measurement of their density, whereas MRI, makes it possible to demonstrate wooden foreign bodies in older injuries in spite of granulomatous changes.