The modality faltered amid radiation concerns, but new technologies are driving a resurgence
This past January marked a defining moment for CT. Nearly 3 years after the National Electrical Manufacturers Association published its XR-29-2013 guidelines—standards concerning the dose and management of CT equipment—the Centers for Medicare and Medicaid Services (CMS) began reimbursing 5% less for scans performed on noncompliant systems. The goal, government officials say, is to incentivize imaging centers to invest in CT scanners that reduce the dose of ionizing radiation without compromising image quality. Tim Allen, an imaging specialist for biomedical services at Cape Girardeau, Mo-based Southeast Health, says XR-29-2013 is more than just another government initiative. For radiology and clinical engineering professionals, it’s a game-changer.
“Hospitals are being forced to upgrade their systems if they want to stay compliant,” Allen says. “And imaging centers that don’t comply with XR-29-2013 will [reap the financial consequences].” Not that he contests such mandates. To Allen, authorities in the United States are just catching up with their European counterparts. “The Europeans have always been more dose-conscious than the US has,” he says. “They’re stricter in some ways.”
The amount of radiation emitted from CT scans first attracted national attention in 2009 when the National Cancer Institute (NCI) published a report projecting that the 72 million CT scans performed on Americans in 2007 alone would result in 29,000 cases of cancer—15,000 of which could be deadly. Women, the NCI said, were particularly vulnerable to radiation overexposure and would account for two thirds of the excess cancer diagnoses. As a result of public outcry and general concern for the American people, the US Food and Drug Administration (FDA) launched a campaign to lower what they deemed “unnecessary” radiation exposure from CT scans, as well as nuclear medicine procedures and fluoroscopic studies. But CT bore the brunt of the FDA’s scrutiny.
Allen says concern about radiation overexposure still exists, but the CT sector is slowly overcoming this stigma. Just look at the numbers: After CT levels slid in 2011, they rebounded strongly in the subsequent 2 years. What matters, Allen says, are results—and CT is known for its superior speed and accuracy. Physicians will order whatever test will provide them with the best information to make an accurate diagnosis, he explains, even if there are risks involved.
The Gold Standard
Matthew Dedman, CT product marketing manager at Siemens Healthcare, concurs, saying that despite ongoing fears about CT’s use of ionizing radiation, the amount of data the modality provides is incomparable. “Yes, people are being more diligent on the physician side as to when a CT scan is prescribed,” he says. “But no other imaging modality can transmit that same amount of diagnostic information as fast as a CT can.” That advantage is why roughly 50% of the CT scans performed in hospitals are driven through the emergency department (ED).
“In an emergency situation, a patient really can’t wait to have an MRI performed instead. Obviously, there’s no radiation dose in an MRI, but the MR exam takes longer and access to MR is a lot less than access to CT,” Dedman says. As a result, he believes that CT will “absolutely” remain the gold standard for imaging in the ED. That’s not to say that CT is without risks, but Dedman believes the benefits of the modality outweigh the “often very limited” radiation dose that is delivered to patients.
Duke University Health System’s assistant director of clinical engineering Grant Smith, CRES, agrees that CT isn’t going anywhere, saying that it provides clinicians with one of the best diagnostic tools available. Use of ionizing radiation or not, CT won’t be replaced with less-divisive imaging methods, such as ultrasound, Smith maintains. For one thing, he says, ultrasound requires technologists with an extensive knowledge of human anatomy and the ability to shift positions on the fly; the skill set needed to perform CT, however, is less specialized. “So there are some fundamental differences that aren’t going to allow the volume of patients to go through a department like ultrasound,” Smith says.
CT also generates a lot of revenue for hospitals and imaging centers. From a biomedical perspective, Smith says this reality is both a blessing and a curse. Any machine downtime cuts into a facility’s profits, which is why he encourages biomeds to practice judicious parts management. Smith’s team, for instance, stores key parts and consumables, such as x-ray tubes, onsite so that they can quickly repair a CT scanner if it breaks. Obviously, purchasing spare parts gets expensive, he says, but it’s better than dealing with patient backlog and missed procedures.
Dedman says the legacy break-fix model—where a machine fails and the OEM or clinical engineer repairs it—may one day be a thing of the past, however. “Where we see the industry going and where Siemens has really invested a lot is in proactive service monitoring,” he says. For CT specifically, such technology facilitates the remote monitoring of x-ray tubes—arguably the most critical part of scanners, Dedman says, and the most costly to replace.
“We can monitor the tube and predict with upwards of 99% accuracy within 48 hours when that x-ray tube will actually fail,” he says. “So then we can proactively dispatch our service engineers to replace that x-ray tube, rather than having to wait for the tube itself to fail and have the provider then call us to replace it.” One reason that’s so important, he says, is that when a critical electrical component, such as an x-ray tube, fails it’s not just the tube that goes out. Other key components of the system are also impacted. “So being able to proactively monitor that component and actually predict when it will fail saves a lot of costs for our customers and saves a lot of downtime, as well,” Dedman says.
The New Normal
After all, saving money is of critical importance to all healthcare professionals, Dedman points out. The 2010 passage of the Patient Protection and Affordable Care Act has placed increased scrutiny on capital budgets—and US hospitals are holding onto their imaging equipment even longer as a result. CT scanners are no exception, Dedman says. No longer are CT departments satisfied with scanners that last 7 years—“Four to 5 years ago, the industry would consider that the typical lifespan of a CT scanner,” he says. Now, hospitals and imaging centers are demanding a 10-year or longer solution.
OEMs, such as Siemens, are also facing demand for upgradable platforms that can extend the life of a CT scanner without a full forklift replacement. “Going hand in hand with that is, ‘Well, if you expect that CT scanner to perform longer in the field —10 years and beyond instead of 7 years—you need to develop techniques to reduce the wear and tear on those systems to allow for that extended useful life,’ ” Dedman says. Siemens’ response to such demands? eMode.
What’s revolutionary about this technology, Dedman says, is that it optimizes scan parameters to reduce wear and tear on CT systems without affecting image quality. Take one of Siemens’ CT scanners with a generator capacity of 55 kw, for instance. Because it’s equipped with eMode, the machine can perform at an output of only 20 kw—which, Dedman says, significantly slows deterioration of both the generator and the x-ray tube. It’s a good thing, indeed, he says, since extending the life of CT systems is more than just a passing trend in the national healthcare sector. It’s the new normal.
Still, keeping up with such technological advancements has its challenges, Southeast Health’s Allen cautions. Allen, who started his biomedical career in 1982—a time, he says, when the first generation of CT systems was being rolled out—admits that modern scanners are much more complicated than their predecessors. CT equipment changes about every 5 years, Allen says, and today’s systems are increasingly computer-driven. “It’s probably the biggest change for me,” he says. Although he acknowledges that a learning curve certainly exists, Allen says current biomeds must be prepared to work on highly sophisticated systems.
A new study appearing in the Journal of Surgical Research shows a two-fold increase in the number of CTs performed on patients with minor injuries, such as fractures and neck strain. Researchers at the University of California-San Francisco (UCSF) examined more than 8 million emergency department visits at 348 California hospitals from 2005 to 2013 and found some staggering results. Despite CT’s use of ionizing radiation, 7.17% of patients underwent at least one CT scan in 2013, as opposed to 3.51% in 2005.
Renee Hsia, MD, senior author of the study and professor of emergency medicine and health policy at UCSF, calls the reasons for such an increase multifactorial. “They range from defensive medicine practices, the superior diagnostic accuracy of CT scans compared with x-rays, to their increased availability and convenience in emergency departments, and the demand to expedite discharge of patients,” she says.
High-level trauma hospitals were much likelier to call for these scans than their low-level-trauma counterparts—with 39% of the CTs in the study ordered at level I and II trauma centers, compared with only 3% at low-level centers. Hsia and her UCSF colleagues say this phenomenon may have a simple explanation, however: Since level I and II trauma centers see sicker patients, they may have standard trauma CT protocols.
The authors recorded a rise in the use of CTs from 2005 to 2009, followed by a gradual drop in 2011—reflecting concern about overexposure—which was preceded by an increase from 2011 to 2013 that almost reached peak 2009 levels.
Smith cites a similar challenge. But as a department manager he’s not only concerned with the technical skills his team needs to repair modern CT equipment. Cost is another consideration. After all, incorporating more technologies into a CT scanner comes at a price—often a very high one, Smith says. “And not all of those costs are immediately visible, but as you get integration into multiple systems and then security in and around the transmission of patient data, there’s a lot of effort that goes into connecting it to multiple locations,” Smith says. “So there are some real challenges in and around what once was fundamentally sending data.” The entire process has become rather painstaking, he says.
Fulfilling American College of Radiology (ACR) requirements is another often-painstaking process, Allen says. Under the ACR’s CT Accreditation Program—launched in 1997—imaging facilities must adhere to certain standards regarding equipment performance, quality control measures, exam protocols, and personnel qualifications. Failing to do so, Allen says, results in reimbursement penalties from CMS. “The ACR is also tracking dose to make sure facilities are in line with the standard dosage measurements out there,” he says. “They’re trying to make sure that the CT modality is safe.”
Keeping CT safe is imperative to the roughly one in 10 Americans who get scanned each year—procedures that run the gamut from staging colon cancer to visualizing the human heart mid-beat. “There are some real incredible CT systems out there right now,” Allen says, remarking how scanners can now complete head-to-toe vascular studies in just 120 seconds.
And these machines are about to become even more advanced, Dedman says, thanks to an industry-wide push to obtain functional data on scans. “CT scanners have always been able to provide visualization of structures that enable sound diagnoses,” he says, “but we’re getting more into the area where we’re getting functional information out of the CT scan, as well.” Technologies such as dual-energy CT and perfusion imaging are facilitating these innovations, Dedman adds.
“Another [innovation] on the clinical side is being able to reduce metal artifacts in CT images,” he says. Since the advent of CT in the ’70s, the challenge of imaging patients with metal implants has existed. Sure, this may seem like a relatively trivial problem, but Dedman says it is anything but. Not only do metal implants create huge streaks and photon starvation artifacts, they often render images nondiagnostic. For patients, that may mean repeated CT procedures—and additional radiation exposure—and for biomedical professionals, such an issue could lead to increased wear and tear on scanners. Fortunately, Dedman says, OEMs such as Siemens are developing metal-artifact-reduction techniques to combat this problem.
Industry professionals say it’s just one of many obstacles the CT sector has to overcome—a point which Dedman doesn’t dispute. But despite public concern about radiation overexposure and pressure from industry regulations, such as XR-29-2013, Dedman projects that the modality will only grow in utilization. Without a doubt, he says, CT is an imaging mainstay and one that will lead the way in medical diagnoses going forward. And for those behind the scenes—the clinical engineers who work tirelessly to keep the systems up and running—CT will continue to provide plenty of employment opportunities.
Keri Forsythe-Stephens is a contributing writer for 24×7. For more information, contact chief editor Jenny Lower at [email protected].
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