Running the numbers: It's time for 3D postprocessing services

May 1, 2007

Multislice CT has steamed into our radiology departments like a nuclear-powered aircraft carrier. In its wake, an entire support industry has sprung up to help us quench our ever-increasing thirst for more and better slices.

Multislice CT has steamed into our radiology departments like a nuclear-powered aircraft carrier. In its wake, an entire support industry has sprung up to help us quench our ever-increasing thirst for more and better slices. Three-D workstations, integrated computer-aided detection, thin-client servers, floating licenses, enterprise-wide distribution through PACS, and virtual PACS are all newcomers to radiology. Of course, high-priced consultants stand ready to tell us how all of this should be utilized in our hospitals and imaging centers.

If I had a dollar for every time I've heard the term "workflow management" over the past year, well, I'd have a lot of dollars. The RSNA meeting last fall was literally bursting with workflow management. The reason should be obvious. If MSCT and advanced image processing were as easy and intuitive as we've been told, we would have no need to discuss workflow management. Our work would flow with no management at all, thank you very much.

But advanced image processing does create workflow problems, for a variety of reasons. One critical area of advanced image processing involves finding ways to best use the talent, training, and expertise that exist in your enterprise to handle the coming flood of MSCT studies efficiently and economically and with attention to the highest quality. The ability to outsource some or all advanced image processing to a centralized laboratory will be key to realizing maximum efficiency by allowing workflow management to occur, literally, on a day by day or hour by hour basis.

LET THE REVOLUTION BEGIN

Through the duration of a typical medical career, most physicians will have the opportunity to experience several events and technologies that truly change the way we practice our craft. As I was completing my training back in the dark ages of the mid-80s, MRI was one such a technology. Interventional radiology (both minimally and not-so-minimally invasive), PACS, and the digitization of our specialty are other remarkable developments that have changed the way medicine is practiced. The rise of teleradiology in recent years would have to be included in that list as well. Teleradiology has broken the outsource barrier in radiology, a profession fiercely protective of its four-walled enterprise mentality.

As revolutionary as these changes were, in my opinion, the development of MSCT and all that goes with it will be the most revolutionary change I expect to see in my professional career. The rapid march from four- to 64-slice scanners has led to technology that is not only faster, safer, and better than the technology it replaces, but cheaper as well. With 256 slices on the near horizon, clinical applications for MSCT will continue to advance rapidly, limited only by the imaginations of my talented colleagues.

POSTPROCESSING: TECHS VERSUS DOCS

The evolving role of physicians, for the most part radiologists and cardiologists, and technologists in advanced image processing is a hot-button issue. Physicians line up to pay thousands of dollars to attend minifellowships and learn how to postprocess scans on 3D workstations. We then return to our practices brimming with enthusiasm over the prospect of creating 3D masterpieces, only to find that making time to postprocess our CT angiography studies is disruptive at best and impossible most of the time. The enthusiasm quickly fades.

Most physicians simply don't have the time to devote to advanced image processing on any sort of large scale. I know cardiologists who are four weeks behind in processing cardiac CTAs. It's only a matter of time until a patient has a myocardial infarction between scanning and interpretation, while the images showing significant coronary disease sit in an office unread.

There can be no doubt that the heavy lifting at the 3D workstation will be performed by technologists. That is not to say that physicians will play no role in the process. Physicians will serve in a supervisory capacity, responsible for setting protocols and troubleshooting individual cases when needed. As the industry matures, the protocols will become more routine and the need for direct physician involvement at the workstation will ease.

The pattern throughout the history of our specialty has been the commoditization of the technical part of image acquisition. Early radiologists were trained not only in interpretation but also in the technical aspects of radiography. Try to find a radiologist today who could shoot a decent three-view elbow series, let alone get an odontoid view. In my residency, we provided a protocol for most CT scans individually. Now in most places, the technologists review the chart for appropriateness and perform a scan chosen from a number of predetermined protocols, calling the radiologist only to problem solve. MRI followed the same pattern. So will CTA and other 3D applications.

BUSINESS CASE FOR OUTSOURCING

Why should there be an outsource option for advanced image processing? Countless articles written over the past few years have advocated the centralization of 3D postprocessing. Doing so, the argument goes, minimizes costs while making maximum use of your workstation and personnel. But are you really maximizing your efficiency when your only resource is your own centralized lab, or are you simply improving it?

I would argue that anyone who takes on the full slate of advanced image processing in his or her enterprise is leaving dollars on the table, lots of them. The inefficiency has more to do with human capital than capital equipment. We are asked to provide imaging services using a fixed number of CT or MR scanners as well as a fixed workforce. Our patient load, however, is quite variable in terms of numbers, complexity, and urgency. What starts out as a light day can quickly become unmanageable. In the old days of slow machines, the speed of the CT scanner was the rate-limiting step in scheduling. With today's rapid scans, the rate-limiting factor is the availability of human resources to move patients from prep to scanner to recovery.

In a study at Massachusetts General Hospital, the addition of a second technologist to a 16-slice CT scanner improved throughput from 22 minutes per patient to 14 minutes. A third tech dropped the number to 11 minutes. The potential revenue difference between one tech per scanner and three was $5.2 million per year. Put another way, the ability to scan one additional patient per day Monday through Friday adds $100K a year to the bottom line.

Imagine the impact of taking your best techs away from the scanner for hours per day to postprocess 3D scans. Keep in mind also the fact that reimbursement from the postprocessing side of the business is trivial compared with the technical fee for the CT scan and will, in all likelihood, never be higher than it is today. It makes absolutely no sense to limit your CT or MRI schedule to accommodate advanced image processing. If you take techs away from your scanners for any reason, you are in fact limiting your schedule on that scanner (see table).

This brings us back to the unpredictable nature of our business. Your ability to do postprocessing in-house may be just fine Monday through Friday during the day or when you are fully staffed with a light schedule and mobile patients. But what happens on those days when a tech calls in sick, all your patients are on stretchers or in wheelchairs, and your top referring doctor insists that you work in four additional patients? What happens in the middle of the night or on weekends and holidays? The ability to outsource advanced image processing to an independent laboratory provides a pressure relief valve that you can use to manage your practice-day by day, hour by hour.

This concept, while new to radiology, is not new to medicine. As a medical student, I remember when blood and other laboratory services were provided in most doctors' offices. Today, virtually all of that work is outsourced to companies like LabCorp and Quest. The return on investment for an in-house blood lab is simply not worth the investment in time, people, and equipment to justify doing it yourself. The key to the outsource model, whether in blood diagnostics or radiology, is providing quality and convenience at an affordable cost.

The Deficit Reduction Act, contiguous body part rules, and other reimbursement cuts are making it imperative that we scrutinize every aspect of our practice and squeeze every dollar we can from our enterprises. Volume will rule the day in imaging, and I'm not talking about volumetric imaging, but about patient throughput. The ability to maximize throughput while minimizing expenses will allow some centers to survive while others fail. An outsource option for advanced image processing is a new concept in radiology that will play a key role in achieving this goal.

Dr. Falk is a practicing radiologist in Louisville, KY. He is also president and cofounder of 3DR, a company that provides remote volumetric interpretations.