By Elaine Sanchez Wilson

CT systems move beyond slice wars and into the future

In a report released earlier this year from Frost and Sullivan, the market research firm pointed to the reality that almost four out of five U.S. hospitals have not implemented an efficient paperless approach to radiation dose monitoring.

Nevertheless, regulatory bodies in the United States and Europe alike have pushed for the reduction, optimization, and tracking of patient radiation dose exposure. For example, the Joint Commission has issued radiation safety and dose standards that address imaging equipment testing and maintenance, staff education, and data collection, among other requirements, while the Centers for Medicare & Medicaid Services has announced reimbursement penalties on imaging providers still using non-compliant technology for CT scans.

“In this context, the industry focus has shifted to developing accurate and efficient dose management solutions that also have intelligence built-in to facilitate both customization and standardization,” the report declares. “Vendors offering diversification over the past few years is a clear indicator that there is no one-size-fits-all solution for dose management today that suits the varying demands and objectives of each facility,” it concludes.

Dose reduction is but one of several key focuses for CT innovation in the year to come. Also on the horizon are advances in image reconstruction and dual-source technologies, and a market emphasis on applications for the cardiac, pediatric, and emergency department spaces, among others.

Reducing Dose

The recipient of Frost and Sullivan’s 2016 Global Dose Management Solutions Product Leadership Award was GE Healthcare of Waukesha, Wis, whose DoseWatch Explore is a Web-based solution designed to measure and analyze dose on multiple levels—from the individual patient, to within a particular department, to across the whole enterprise. The technology is compatible with the line of CT systems that the company re-launched in 2014: the Revolution CT, the Revolution HD, and Revolution EVO.

“The Revolution CT is our highest-performing CT platform, and the key breakthrough is it is the first CT that delivers, for the first time, both the highest spatial resolution, the highest temporal resolution for freezing the motion of the heart in cardiac scanning, and the widest coverage in terms of the number of slices or the amount of anatomy you can image in each rotation,” says Scott Schubert, GE Healthcare’s general manager of global premium CT.

Focusing on these three key technical capabilities—spatial resolution, temporal resolution, and coverage—the Revolution CT was developed to produce diagnostic quality images in challenging patients, such as those with a high heart rate, metallic implants, or those who are noncompliant.

“Cardiac imaging is the marque application for the Revolution CT, and it is able to really drive new standards of care and clinical improvements,” Schubert says. The system freezes cardiac motion in one heartbeat, reducing metal artifacts and supporting sedation-free CT scanning. Additional benefits include 16 cm whole-organ coverage, the Gemstone Clarity Detector, and a new gantry that enables imaging at a 0.28-second rotation speed and tested to support rotation speeds up to two-tenths of a second in the future.

At the 2016 annual meeting of the Radiological Society of North America (RSNA), which takes place later this month, GE is introducing the Gemstone Spectral Imaging (GSI) capability on the Revolution CT. The application—which is pending FDA premarket notification 510(k) clearance and not yet available for sale in the United States—uses rapid kV switching to acquire dual-energy samples almost simultaneously. This, then, generates material density data that can be used for the separation of materials and derivation of monochromatic spectral images.

“The exciting part about GSI and spectral CT is we’re really moving CT beyond anatomy visualization by the physician to where we can now characterize tissue chemical composition and function, by looking at different material types and the functional information of how the tissues are processing things like blood flow,” Schubert says. “For the first time, with spectral CT and GSI we will now be able to visualize the anatomy exquisitely, like we’ve always done in CT, and we’ll be able to do that with better contrast in terms of seeing more subtle anatomy in regions.

“This really is important because the anatomy is usually where the physician detects the disease and the function is where they can make the differential diagnosis in order to determine the next therapeutic steps,” Schubert continues.

Dual-Source Scanning

Dual-source scanning is a CT feature with which Malvern, Pa.-based Siemens Healthineers is making significant strides. The company recently announced FDA clearance of its Somatom Drive CT system, a dual-source scanner that seeks to drive precision in diagnostic imaging across a wide range of clinical disciplines and to offer the potential to reduce examination time, preparation, and follow-up care. The system represents the next-generation iteration of its dual-source predecessor, the Somatom Force, which debuted at RSNA 2013 and received FDA clearance in 2014.

The new Somatom Drive CT system is suited for a range of clinical disciplines, including pediatrics, emergency medicine, oncology, and cardiology. Equipped with new Straton MX Sigma x-ray tubes and Sigma generators, the system enables targeted beam focusing using high energy levels at low voltages. Not only do the lower voltages allow clinicians to use less contrast, they are adjustable in 10 kV increments ranging from 70 kV to 140 kV.

“Dosage is really important to the industry, and personalizing that dose is critical,” explains Christine Ziemba-Landon, CT product manager at Siemens Healthineers. “Depending on the clinical task and the size of the patient, the system automatically chooses the kilovoltage that’s most appropriate. We have a range of kV’s from 70 all the way to 140 on the Somatom Drive, in increments of 10. That’s where the personalization comes in. Everyone is very different in size and shape, so now they can be custom fit, with the correct voltage.”

The system brings with it a number of benefits. For one, the scanner’s Dual Energy mode can help clinicians accurately differentiate between tissue and bone. Additionally, it enables cardiac scanning to be performed in one heartbeat, therefore possibly eliminating the use of beta-blockers to slow the heartbeat of some patients.

“The temporal resolution is the lowest on the market at 66ms, and that’s why we’ve seen great success in the cardiovascular space as well as EDs, where time is of the essence,” says Ziemba-Landon. “It’s very important when performing structural heart imaging that your images are motion-free because they’re making very precise measurements, and they’re often custom-fitting devices.”

The technology also helps enable CT lung scans to be performed at a low dose, and supports pediatric CT studies without the need for sedation.

“From a patient care standpoint, the dual system is well-positioned in the pediatric space. Because we have two x-ray tubes in the system, we’re able to scan patients at extended pitches or shorter times—often, sub-second imaging that lends itself to free-breathing imaging,” says Ziemba-Landon.

“That’s important for patients who are confused, as well as pediatric patients that are in continual motion. Ultimately, customers want to get away from, as much as they can, sedating patients. With the entire dual-source portfolio, the options are free-breathing imaging and sub-second acquisitions.”

Furthermore, the system sports accessories that were designed with technologist as well as patient comfort in mind.

“The new touch panel is much like an iPad on the sides of the gantry,” says Ziemba-Landon. “That allows the technologist to stand table-side longer with the patient. The technologist can select a protocol, and can do a number of tasks right at the table-side. It keeps them closer to the patient longer, which is important in adult imaging and, in particular, pediatric imaging.”

Customer Impact

Consensys Imaging Service Inc.—a Cary, Ill-based company that specializes in diagnostic imaging equipment service—holds two U.S. patents for real-time x-ray dose monitoring and remote monitoring of medical devices, as well as two ISO quality certifications. And as an approved service provider for GE, Siemens, and Philips Healthcare, Consensys is well-versed in servicing a variety of CT, MR, mammography, and ultrasound systems.

According to Jim Spearman, Consensys’ president and CEO, one of the most important characteristics for CT systems is uptime. “It’s a danger for your patients; if someone is in a trauma situation, that CT needs to be running and they need it quickly,” Spearman says. “The clock is ticking, you need to find out if they’ve got a brain bleed, and you have to find out what’s going on internally now because they might need to be rushed right into surgery.”

Spearman says if Consensys were to write a service contract with a customer, it would have those elements in it: onsite response time, preventative maintenance completion, uptime commitment, and parts response.

“Virtually, the focus is to make sure that we have limited downtime, if any,” adds Pam Stater, director of molecular imaging/CT modality service at GE Healthcare. “Then we keep continuing to make sure that we have different offerings segmented that we partner within the organization.”

“If an organization, for example, wants a full service and wants us to service it, we have that option. We also realize that there is a moving trend to have in-house servicers or biomeds within the hospital or facility that services their own equipment,” Stater says. “We also have offerings for that type, so that they may not necessarily need us right away, but they may need some phone support. We have offerings such as that to help enable that partnership between us and customers.”

Various options exist, Stater says, and GE is tailoring its offerings to meet customers’ specific needs.

Moreover, Spearman says that with the slice wars settling down, he notices three main improvements in the CT landscape: better cooling, higher image quality, and faster processing. Nevertheless, innovation also brings with it certain challenges, he points out. In his case, the key issues he must work around are frequent CT tube releases—“there should be some consolidation because there’s just too many of them,” Spearman laments—in addition to power management.

“We’ll go in and do a test on power, and the three things that we typically find is that it’s either not grounded properly, it’s not on a dedicated line, or there’s what’s called a step up transformer,” says Spearman. “That’s when the power was brought in at a lower level and has been stepped up to the specifications that the CT needs to run.”

According to GE’s Scott Schubert, when CT systems are new to the market, many biomed facilities will go with OEM-based service because of the new diagnostics that the OEM can provide. “When you’re buying a state-of-the-art CT system that is really a critical-care system, many biomeds rely on the OEM for those early years after the product is introduced,” Schubert says. “I think, over time, they become more comfortable with the system, but in the initial years, the flagship systems tend to be serviced by the OEM.”

Still, CT servicing is as popular as ever for companies like Consensys. “We have customers in major metro areas that are running between 24 and 26,000 patient scans per year,” Spearman shares, adding that his company will provide service during the warranty period. “There are very high-quality alternatives to OEM service for CT scans.”


Ultimately, manufacturers and servicers alike look forward to the next chapter in CT innovation, beyond the slice wars of the past.

“I lead our engineering development and, where it used to just be the next CT was going to mean more slices and spinning faster, we’ve now got an innovation in cardiac, in spectral imaging, in stroke imaging, dose-reduction technologies, and our cloud-based tools for advanced visualization,” says Schubert.

Today’s CT innovations are much more multi-dimensional, he concludes, boasting greater clinical applications and new digital cloud-based technologies.

Elaine Sanchez Wilson is associate editor of 24×7. Questions and comments can be sent to [email protected].