Dual-energy CT: Is it what the doctor ordered for the cost-conscious community hospital?

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A hospital seeking to replace CT technology that does not meet the XR-29 standard has a wide range of slice counts and capabilities to consider, all the way up to state-of-the-art—but pricey—dual energy CT (DECT).

For hospitals in the community-provider category, however, dual-energy CT capability likely represents overkill when it comes to meeting the typical caseload of a radiology department in the  community hospital setting. Focused on right-sizing their technology due to cost-effectiveness concerns, many hospital radiology administrators are foregoing DECT purchases.

So concludes Greg Freiherr, a journalist and consultant who has covered and closely tracked the field of medical imaging technology for 32 years. Freiherr fleshes out the details informing his conclusion in a white paper commissioned by Hitachi Medical Systems to best understand the imaging needs of today’s community hospitals.

He identifies two factors behind community hospital reluctance to adopt DECT. One, the shift in U.S. healthcare from volume-based reimbursement to a thriftier value-based model proceeds apace. And two, mid-tier 64- and 128-slice CTs continue to prove adequate in handling not only a vast swath of routine radiological exams but also most advanced cardiological and neuroradiological ones.

Freiherr’s methodology included examining peer-reviewed journal articles for clinical data and analyses about the use and adoption of spectral and dual-energy CT, along with interviewing experts and radiology administrators, and correlating their experiences with information obtained online and in print.

He spoke with imagingBiz about the project and the observations he made while working on it.

“Dual-energy CT is probably the most advanced technology that we have in computed tomography,” Freiherr says. “But you are not going to find a lot of benefits in the business returns on the investment, especially for community hospitals. You truly are looking at purely clinical benefits in very selective areas.”

What is DECT and why is it here?

DECT technology leverages the propensity of anatomic structures and elements within the body to absorb and attenuate x-rays differently, depending on the level of energy sent into them. The technique allows a diagnostic imager to obtain two sets of data in every CT slice—one at lower energy, such as 60 or 80 keV, the other at higher energy, such as 120 or 140 keV.

Freiherr’s paper notes that, while this dual capability is unique to DECT, the latest generation of 64- and 128-slice CTs also can be set to scan at low energy, typically 80 keV.

“In certain circumstances, you can see more, ironically, with low power then you can at high power,” Freiherr explains. “With DECT you can finesse the imaging so that you’re able to look at certain disease conditions from two views, with or without contrast.”

DECT has been on the market in the U.S. since 2006. The first iteration relied on the use of two x-ray tubes, Freiherr says. Soon others systems appeared using a single x-ray tube that switched between two energies and  CT detectors that could sort out energies contained in a multi-energy beam.

The technology is well suited to fine-tuning diagnosis and guiding treatment for conditions such as gout and kidney stones. The latter problem is an especially good example, Freiherr points out, because the chemistry of most but not all kidney stones involves calcium, which absorbs the energy at a specific level. “The ability to distinguish between types of stone can be handy,” he says, “because the therapy for one kind of stone is completely different than the therapy for the other kind.”

Freiherr noted, however, that less expensive—although more time consuming—means exist for distinguishing between these stones.

At the same time, DECT has some attractive dose-reduction aspects. Because it acquires data sets at two energies, a patient may be administered contrast and scanned just one time. The contrast can be virtually subtracted by algorithm, providing the diagnostician with two exams, contrast and non-contrast, out of that single scan. “In a contrast-enhanced CT angiogram, for example, you cut your radiation exposure to the patient by 50% just like that,” says Freiherr, who noted that lower patient doses of radiation also can be achieved using conventional CT.

Dollars and sense 

The price of CT scanners has fallen dramatically in recent years just as their diagnostic power has risen.  Comparing price points, Freiherr’s white paper