Understanding ROI in CBCT Technology
Multimodality and software capability should be at the top of your list
Brian Trava, DMD
The acronym ROI is frequently used when discussing cone beam technology, but depending on your orientation, it may have two different meanings. The diagnostician will tell you that ROI is defined as “Region of Interest.” The businessman will tell you it means “Return on Investment.” With CBCT technology, you really are investing in the capability to see detail. But if you do not understand the details of your purchase, you may come up short in your investment and, most importantly, in your diagnostic abilities.
Many practitioners do very little research before making their imaging purchase, which leads to insufficient understanding both before and after the purchase. Having an underutilized CBCT taking up space is like an exercise bike with clothes hanging on it. In the decision-making process, price should be at the bottom of the list, while multimodality and software capability should be at the top. With the diversity of financing, Section 179 of the tax code, and added value to office resale, the long-term numbers are insignificant. If the machine you choose is limiting or not upgradable, it may be no different than an old dental chair that costs money to dispose of. Evaluate your current practice needs, and make your decision on your future needs.
An important tip for purchasing a CBCT machine for your practice: artifacts influence clinical diagnosis and treatment. Detail gives higher patient acceptance and increased accuracy. When studying a Region of Interest (ROI), how does the software handle metal artifacts to provide detail and eliminate distortion? High-density objects (such as amalgam fillings, PFM crowns, posts, and implants with high-attenuation coefficients that create streaks, starbursts, and dark shadows corrupting the imaging detail) are unavoidable when most of your scans will be on patients with a wide range of dental work. Diagnosing is about detail; you are purchasing detail, and you expect detail to be delivered. Can your machine manage metal artifacts without any compromise of detail?
When you are studying the ROI of any dental imaging purchase, note how are artifacts handled within the field of view (FOV), and how that is related to detail. A CBCT machine can run an algorithm artifact removal program to reduce the streaks, but the actual metal object that is causing those streaks must be within the FOV for the artifact removal algorithm to work. The first image shows a small volume 5 X 5 FOV: An artifact removal was run, but streaks and interference are present. The artifact removal algorithm program has no effect on any metal objects that are outside the FOV volume, and your Region of Interest (ROI) can be detail compromised (Figure 1). Therefore, if you are looking for a fracture in a tooth in a small volume size, you need to consider what high-density objects are in the contralateral and surrounding teeth.
When researching CBCT machines, our office made the decision on the Planmeca ProMax® 3D (planmeca.com) for many reasons. With regard to FOV and artifact removal, the software platform is the most versatile. You have the option of a small FOV to a larger field of view of 8 X 8 if needed to capture within and process out high-density metal artifacts pending their proximity to your ROI. Next, the ProMax 3D gave us the option to have a raw volume with no artifact removal, or to run a scaled integrated amount of artifact removal depending on the quantity of high-density artifacts that may interfere with the ROI. These programs may be non-forgiving because they cannot distinguish between important and not important in the ROI.
Endodontics is about detail. We did not want a CBCT machine that locked us into a standard artifact removal program that we could not control. In Figure 2, there is no artifact removal program with an obvious fracture. In Figure 3, an artifact removal program was run showing a dilution of detail with regard to the fracture. In many patient cases, we need that edge, and prefer not to run any artifact removal.
As our practice grew, a second CBCT was needed. In the meantime, more companies and machines had entered the marketplace. When doing the research, versatility again was an important factor, and we decided to add a second Planmeca ProMax 3D. CBCT is about detail, diagnosing, and treatment planning. Educate yourself before your purchase, recognize your future needs, become a better diagnostician, and your Return on Investment (ROI) will always be long-term.
About the Author
Brian Trava, DMD, is an endodontist in New Jersey. You can learn more about his practice at http://njrootcanal.com/. Dr. Trava is a paid lecturer for Planmeca.