Venous air embolism is a known complication of contrast-enhanced Computed Tomography (CT), and prevention of air injection is an important topic, especially when a power injector is used. Although serious events due to injections of large amounts of air are extremely rare, studies show that small amounts of air have been found to occur in up to 55% of all contrast-enhanced CT procedures. These small bubbles, while generally not a safety threat, are visible in images and may generate artifacts. For power injectors with air sensors, detecting air during the procedure interrupts the injection and may cause unnecessary radiation exposure to the patient if the scan must be repeated. It also disrupts the workflow in the CT suite.
This work reviews the challenges of air management for contemporary power injectors, proposes a novel approach that is more proactive, and analyzes the injected air volumes under simulated clinical use. With this new technology, monitoring for air during injection is no longer the primary approach for preventing air from the reaching the patient. Instead, prior to injection, inlet air detectors prevent attempts to fill disposables from an empty bottle, vacuum air removal (a novel technique) eliminates air bubbles from inside of the fluid path, and reservoir air detection (also a novel technique) performs a final safety check before the injection even begins. These proactive techniques are used in combination with an outlet air detector, which monitors the fluid path during injection.
While all tested systems prevented the injection of large air volumes, this was not the case for small bubbles, which may be injected without being detected by the air sensors. The new proactive approach successfully reduced the amount of injected air under simulated use, which could translate in practice to fewer imaging artifacts and fewer workflow disruptions.