From the March 2016 issue of HealthCare Business News magazine
In general these systems are quite reliable, but require at least an annual maintenance and safety check, and in case of high utilization, a service every six months. The cost for these service procedures is typically between $500 and $1,500.
More of a problem is the consumables that are required for the different injector systems. Some use syringes with recommended single use that are very often only replaced once a day. However, others use bottles or bags that can contain larger amounts of contrast media and do not need to be replaced for every patient. Tubing from the syringe/ bag to the patient obviously needs to be replaced with every patient and the total cost per patient can run from $5 to $25, plus the cost of the contrast media. Investment as well as operational cost in combination with the required individual patient setup time is certainly something that needs to be taken into consideration when selecting an injector.
For CT injection protocols, timing is essential to achieve the desired contrast. A relatively standard volume is between 75ml and 150ml, depending on patient weight, iodine-based contrast media using an injection rate of typically between 3-5ml/s (using a 20-gauge flexible plastic cannula). The injection protocol also needs to be adapted to the type of CT scanner used (number of slices) and is complemented with the injection of saline solution which requires two working channels as a syringe or bag system. Timing of injection is critical with respect to the CT imaging and a computer control is therefore essential.
Typical MRI contrast media injection (gadolinium-based, which shortens the T1 relaxation time) is administered as a rapid intravenous bolus, depending on weight (approximately 0.2ml/kg) at a flow rate of 2ml/s. For a 100kg (220-pound) patient approximately 20ml of contrast media is used that is subsequently flushed with 20ml of saline solution at the same injection rate. Approximately 30 seconds after that the MRI imaging protocols start. The peak enhancement is about 2 minutes after injection and holds on for several minutes. The standard MRI contrast media injection protocol is relatively simple, and the injector would theoretically only require one or two different flow rates and simple timers for 90 percent of all applications.
Technically the injectors only require a driving unit that is capable of injection at a flow rate of 2ml/s (MRI) or 4ml/s (CT); a volume of 20ml (typical MRI) to 150ml (CT) contrast media with injection of saline solution before and immediately following the contrast media injection. There are some rarely-used advanced protocols that require multiphase injections and varying flow rates, but with the above minimum specification a large majority of the normal contrast media imaging could be accomplished. The currently available injectors can do significantly more than is required for these standard injection protocols. Easier, less costly and less complex solutions could be developed, especially for use in the MRI suite, where plastics and avoidance of electronic systems/components are also solving the problem of MRI compatibility/safety.
