Microbial Safety Assessment of a Double Check-Valve Patient Line in a Multiuse Contrast Delivery System

To demonstrate the microbial safety of a secure filling and injection kit designed to allow for multiple injections of contrast media from a single large-volume container in computed tomography (CT) and magnetic resonance (MR) imaging examinations.

Two male Papio anubis baboons were injected with technetium-99 labeled albumin to mimic a contaminated patient. Researchers injected iodinated contrast medium into the animals using an automated power injector via an antecubital vein, with an injection line fitted with a double check-valve positioned at a 45° angle toward the vein (worst-case condition). Two contact times (before and after injection) were assessed in 3 experiments and repeated 3 times for a total of 9 tested lines. Radioactivity levels were measured in the animals' plasma and in the injection system.

Crude values were corrected for background signal and technetium Tc 99m radioactive decay. Results showed an absence of contamination in the line above the check-valve. Negative results were because the mean value of background noise was similar to the crude values measured.

Injecting contrast media from a large-volume container decreases the cost of CT and MR examinations. However, this practice, which involves the use of the same injection system for multiple patients, is associated with a risk of cross-contamination and requires manufacturers to demonstrate the safety of reusable injection kits.

Based on appropriate demonstration of worst-case conditions and the use of a radiolabeled molecule mimicking a pathogen particle (ie, as small as viral particles), this study highlights the safety and performance of the tested injection system to perform repeated injections from a multidose container to more than one patient, regardless of the conditions and duration of the examination.