Contrast media injectors are part of the medical equipment used to deliver fluids in examinations such as CT, MRI, fluoroscopy and angiography. Many of these diagnostic imaging procedures include the administration of intravenous contrast agents to enhance the blood and perfusion in tissues.

Mainly there are two types of injector technology:
See also Single-Head Contrast Media Injector, Dual-Head CT Power Injector, Syringeless CT Power Injector.

The use of x-ray contrast agents in computed tomography (CT) began with a hand injection by the radiologist in the scan room. During its history, CT scanners have made great improvements in speed and image quality. Actual CT systems with multiple detectors allow scan times of a few seconds per body region. Some CT protocols require multiphase scans, where a body region is imaged with a single bolus of contrast in different blood flow phases. Automatic power (pressure) contrast media injectors are required to provide precise control of flow rate, volume and timing of injection. The use of a saline bolus following contrast administration reduces the volume of contrast required.

Most relevant topics for the use of a power injector in medical imaging procedures such as contrast enhanced computed tomography (CECT):
Must have basic injector control options:
Examples of other injector control options:

Multi-head contrast media injectors offer flexible contrast media management, simplified workflows and increased patient safety.
Contrast delivery is much more controlled and efficient when using a dual-head CT power injector. These medical devices are needed to enable the short imaging times typical of multidetector computed tomography (CT) scanners.
Triple-head injectors allow selection of a second contrast agent when two different contrast agents are used, or switching to full contrast agent containers when two identical contrast agents are used.

See also Contrast Media Injector, Syringeless CT Power Injector, Single-Head Contrast Media Injector, CT Power Injector.

Single-head contrast media injectors ('contrast only') have been first developed in the 1970s. The construction consists of a syringe with the contrast medium inserted into the injector head and a plunger to deliver the contrast medium from the syringe via tubing connected to the patient.
Injectors used in cath lab angiography are often single-head injectors using one syringe.
Angiography contrast delivery systems inject contrast agent into arteries, where air embolisms can present a serious risk. For that reason, cath lab pressure injectors should have air embolism detectors, warning of bubbles in the line before they reach a patient. Air embolisms are not a major issue for CT scans, due to the venous access any small bubbles injected into a vein are expelled through the lungs. Procedures in the interventional suite need low, variable flow rate injections.

See also Contrast Media Injector, Dual-Head CT Power Injector, CT Power Injector, Multi-Head Contrast Media Injector, Syringeless CT Power Injector.

The industry standard of computed tomography (CT) contrast media power injectors changed over time from single-head to dual-head systems. The advantage of a power (or pressure) injector with two syringes is that a saline solution can be injected first to open the veins, followed by a second injection with contrast agent. Then the first head flushes the saline to maintain contrast flow. As a result, much less contrast agent is needed (about 30 percent less), helping to reduce costs. Dual-head contrast media injectors also provide greater patient safety by reducing the pressure of the flow rate, helping to prevent damage to the veins.
Contrast delivery is much more controlled and efficient when using a dual-head power injector (also called double-piston injector). Also, these medical devices are required to accommodate the quick imaging times typical for a multi-detector CT scanner.

See also Contrast Media Injector, Single-Head CT Power Injector, CT Power Injector, Multi-Head Contrast Media Injector, Syringeless CT Power Injector.

Syringeless CT power injectors (also called pressure injectors) have been developed as a solution to reduce contrast fluid waste. The Joint Commission does not allow the reuse of unused cans from disposable syringes, so the syringeless option allows facilities to use contrast media as efficiently as possible.
A syringeless CT (computed tomography) contrast media injector permits delivery to be made directly from standard contrast media bottles, featuring multi-dosing and programmable automatic saline flush. This higher loading capacity for contrast agent ( up to two contrast bottles or 1000 ml) and a bag of saline at initial setup, enables to perform multiple contrast enhanced CT scans without reloading contrast agent; resulting in increased efficiency and less waste.

See also Single-Head Contrast Media Injector, Dual-Head CT Power Injector, CT Power Injector, Multi-Head Contrast Media Injector.