In most cases, extravasation of contrast media is a selflimiting event that resolves spontaneously within 2–4 days. However, severe cases may progress to tissue necrosis or even acute compartment syndrome. Most cases are seen following CT or MRI using automated power injectors.

The exact pathogenic mechanism leading to tissue damage after extravasation of contrast media is unclear. It is, however, clear that osmolality and volume of the extravasated contrast media play a role. High-osmolar agents induce more damage than low-/iso-osmolar agents. Severe skin lesions are more common following extravasation of larger volumes.

Patients unable to complain about pain at the injection area (i.e. infants, small children and unconscious patients) are at increased risk of contrast media extravasation. Other risk factors include chemotherapy, arterial or venous insufficiency, atrophy of muscles and subcutaneous fatty tissue. Chemotherapy is a risk factor as it might induce weakness of the vascular walls.

The clinical presentation of contrast media extravasation is variable. Usual symptoms are pain and discomfort at the injection area, but some cases are asymptomatic. Clinical findings are a red, swollen and tender extravasation area. It may be difficult to separate extravasation from local irritation and hypersensitivity reactions. 

There is no consensus on treatment of contrast media extravasation. Conservative treatment with elevation of the limb along with topical application of warm or cold is used in the majority of cases.38 Limb elevation reduces the hydrostatic pressure and thus reduces swelling. 

Topical application of warmth leads to vasodilatation, promoting resorption of extracellular fluid. On the other hand, application of cold leads to vasoconstriction and has an anti-inflammatory effect. More aggressive therapy with surgical suction or topical aspiration of the extravasated contrast media is controversial and should be reserved to the most severe cases.

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