Over the last few years, more and more C-arm technology has begun embracing the same trends the industry has seen in interventional labs – namely, a move from traditional image intensifiers to digital flat panel detectors (FPD). As FPD options become more available, anyone considering the purchase of a C-arm is increasingly likely to be confronted with the big decision: analog or digital?
Below are some aspects of C-arm hardware that buyers should bear in mind when making this choice:
The Image Intensifier (II)
The II is the current standard for C-arms and is found on the vast majority of systems in use today. They are capable of providing high-quality images for a number of years but, eventually, they all lose image gain and the image quality decreases gradually. They can be a pricey component to replace but, fortunately, used and refurbished IIs are easy to find on the secondary market.
In place of an II, an FPD C-arm has a flat detector like those you might see on GE’s Innova series cath labs or Hologic’s Selenia mammos. These exhibit very limited image degradation and over a much longer period of use than an II.
A fact of using an II is the need to collimate down for higher magnification. More detail becomes visible, but the field of vision is reduced with each step up in magnification. On the other hand, magnification on an FPD system doesn’t reduce scale at all.
FPD C-arms have the potential for higher image resolution than their II predecessors. Resolution varies from model to model, but overall, FPDs have the ability to produce a more consistent high-quality digital image.
Keep in mind that, apart from acquisition, proper technique, quality of monitors, and post-processing have a significant effect on image quality. If these aspects are not properly accounted for and maintained, it is also possible that an II can outperform an FPD.
Why an II System Might Be a Better Fit
So far, everything you’ve read points to FPD systems as superior. If the only factor you’re considering is image quality, it’s true – FPD systems have the capacity to produce clearer, sharper images than your average II system. However, for many facilities, there are more variables that come into play. Below you’ll find a few areas where an II-equipped C-arm might make more sense.
New FPD units costs around 2 to 3 times more than their II counterparts. Also, because FPD technology is so new, it’s virtually impossible to find a used or refurbished system, leaving new as the only likely recourse for the facility that “must have” the latest.
Refurbished II C-arms are common and encompass a far wider range of price points.
Service & Parts Price
Unless we’re talking about baseball cards or classic cars, newer items cost more than older ones. When you place your FPD C-arm under service coverage, your agreement will likely cost 50-60 percent more.
You are also at the mercy of the OEM for spare parts. There are no used detectors on the market for any of the three big OEMs that are currently making FPD C-arms. While it’s no fun to pay thousands for a used II, they’re readily available. On top of that, it’s even harder on the budget (tens of thousands) to buy a brand-new digital detector.
The Long and the Short
There are countless want vs. need. vs. budget scenarios out there, but, in spite of all these variables, we can offer this relative to choosing between an FPD and an II:
On the high end of C-arm systems, an FPD C-arm will give you optimum image quality. Keep in mind, though, that a good portion of your budget should be reserved to handle the larger parts and service costs.
For facilities with a smaller budget, we suggest a late-model, used II system. While the image quality capabilities won’t be as high as those of a digital system, II technology has been used for years and is still reliable for use in your general case load.
The long and the short of it is: FPD C-arms have some powerful hardware advantages. If you can afford one, you won’t be disappointed. If an FPD is outside your limits, an II C-arm can still serve you and your patients well until circumstances change.
Chris Sharrock is the VP of C-arms and X-ray at Block Imaging. Sometimes referred to as the “The C-Arm Guy”, Chris has a passion for music, fitness and genuinely enjoys helping others make decisions about C-arms.