Augmented arterial flow and pressure resulting from selective injections through catheters: clinical implications.

Injection of fluid through catheters positioned selectively in arteries results in substantial increases in flow and pressure in those arteries for the duration of the injection. This produces certain artifacts which may lead to misinterpretation of the arteriograms. Apparent direction of flow in major vessels, extent of collateral circulation, distribution of contrast medium throughout various branches of the arterial tree, and density of accumulation of contrast material in organs or tumors can be altered significantly by the injection technique.