CT demonstration of intravenous contrast medium extravasation and subsequent resorption in the mediastinum: a complication of a central venous catheter injection

Extravasation of iodinated contrast media into peripheral soft tissue at the site of intravenous (IV) injection is a familiar complication. Although the reported overall rate of extravasation is relatively low (0.04%-1.3%),¹ it is commonly seen because of the large number of radiological studies that require the use of IV contrast media. In particular, the increasing reliance on power injectors that deliver contrast media at a fast rate for CT studies has necessitated a high level of awareness of the nature of extravasation, its prevention and treatment. Occasionally, an alternative route of contrast administration may be required in patients with poor peripheral IV access, and an existing central venous catheter is used in some institutions although this practice is discouraged by most manufacturers of such catheters.² Even though the central line is carefully checked for patency and integrity and the injection rate is typically lowered, a theoretical risk exists for extravasation along the course of the catheter and, specifically, into the mediastinum. However, there is little documentation in the literature of the natural course of extravasated contrast media in the mediastinum. We present a case in which contrast medium was extravasated into the mediastinum of an individual with cancer. This followed injection of the medium into an existing surgically implanted catheter and was depicted on initial CT. Complete resorption of contrast medium was demonstrated on follow-up CT 24 h later.