GE Healthcare prepares volumetric ultrasound for next RSNA meeting

GE Healthcare will focus on volumetric ultrasound at the RSNA meeting this year - not the postprocessing, time-consuming kind that has come to characterize 4D ultrasound for much of the past decade, but one that acquires volumes of data that remain intact and can be interrogated later on. It's an important distinction that GE executives hope will change the practice of ultrasound and provide the company with an edge over its competitors.

For more than a decade, ultrasound companies have been hawking 3D and its dynamic cousin, 4D. They all had their own tricks, their own algorithms. But always the approach was the same. Ultrasound scanners and offline workstations processed data into volumes that could be turned and twisted but were as immutable as stone. GE has taken a different route.

The 4D transducers and software built into the company's newly enhanced Logiq 9 radiology system will assemble a volume of raw data that, once captured, can be plumbed as needed for better viewing angles or other reconstructions.

"With this system, you can go to the source data if you don't see what you want the first time," said Terri Bresenham, vice president and general manager of global diagnostic ultrasound for GE.

Images acquired during the scan are displayed instantaneously, she said, noting that "you can literally put the probe on the patient and see 3D in real-time."

They can be presented as volumes or planes along different axes. Quantifications previously impossible become practical.

"There is a wealth of ways to use this volumetric information that will lead us to more sophisticated ways of interpreting diagnostic information," she said.

Among them is the quantification of volumes not easily interpreted visually. Physicians might measure fluids in a baby's lung, tracking whether those fluids are accumulating or decreasing, Bresenham said.

Quantification underscores the novel way that volumetric ultrasound may be applied, but it is not the only way. Volumetric ultrasound traditionally has been associated with 3D images, most often a prenatal face. But operators of GE's Logiq 9 will more likely present volumetric data in multiple planes to create images more akin to MR and CT images, according to Bresenham.

And advanced clinical algorithms will provide further assistance. An inversion capability allows tissues to be selectively subtracted. This process might be used when trying to count the number of ovarian follicles, a difficult task made simpler by digitally erasing the surrounding tissue.

"Volume ultrasound is on the verge of taking off," she said. "It provides an orientation of anatomy not seen in the past."

The 4D Logiq 9 is ready to ship. It will make its first appearance as an integrated system at the upcoming RSNA meeting. Two weeks ago attendees at the Society of Radiologists in Ultrasound meeting in Washington, DC, got a preview of the 4D probes. The company has also begun showing the new product to prospective buyers in different cities across the U.S.

Postprocessing algorithms built into both the scanner and the workstation can compile and reconstruct data acquired with standard ultrasound probes, if the operator is skilled enough to manually sweep the region of interest. GE, however, has developed three new 4D probes - one each for endocavitary, abdominal, and small parts imaging - that automate the acquisition of volumes and optimize data quality.

Sure to be highlighted at the RSNA meeting is GE's "belly buster" probe, designed for use with obese patients. The convex probe, with frequencies ranging from 1.5 to 5 MHz, allows deep abdominal penetration through layers of adipose tissue and offers a narrow footprint for intercostal placement, yet is lightweight so as not to fatigue operators.

About 20 sites have been running 4D versions of the Logiq 9 for the last six months as part of the product's clinical evaluation. Many of these use the LogiqWorks workstation for offline processing. Processing can be done by the scanner or an upgraded version of GE's LogiqWorks workstation. The only caveat is that doing advanced processing on the scanner slows down data acquisition.

The workstation costs about $25,000, according to Bresenham. Volumetric imaging can add $70,000 to the $180,000 price of the Logiq 9 itself, bringing the total price of a new system to the "pain threshold" of a quarter-million dollars for buyers of ultrasound equipment. The actual price will depend on how many probes are included. But the investment might pay for itself - and quickly.

A luminary study at Florida Hospital Celebration Health in Orlando documented that the use of a Logiq 9 in tandem with a LogiqWorks ultrasound workstation cut the time of an exam by more than half. Scan time dropped from about 10 to 15 minutes with 2D imaging to three to five minutes with 4D. Review time went from five to 10 minutes to three to five minutes. Report generation was cut from seven to 10 minutes to between five and seven minutes. Improved diagnostic confidence and exam quality reduced the need for rescans by 50%.

Some savings might accrue from just using the Logiq 9, as the system alone promises shorter scanning periods and shorter readout, according to Bresenham. But the real benefit comes from using the 4D scanner and workstation together.

Until now, radiological applications of volumetric ultrasound had been seen as adding time to the diagnostic process rather than reducing it. Volumes reconstructed offline were set in stone. However the data were processed was how the image looked. The flexibility of GE's approach remedies this.

"We were very sensitive as we created this paradigm that we not add time for the sonographer or physician," Bresenham said. "We've made it faster."

But GE's take on volumetric ultrasound promises more than increased productivity. Being able to interrogate a 3D database could improve clinical confidence by revealing aspects of an abnormality that would otherwise have been missed.

"The 4D imaging that provided compelling pictures of fetuses is now migrating across all applications," said Omar Ishrak, president and CEO of GE's diagnostic ultrasound. "It is only a matter of time until all ultrasound exams are done in 4D."

GE is recommending that customers complement the 4D-enhanced Logiq 9 with the LogiqWorks workstation, which combines GE's raw data processing algorithms and a multimodality Centricity PACS workstation in one. LogiqWorks can display and process information from any digital modality. It also offers advanced clinical applications, including quick organ review, multiplanar measurement tools, and volume analysis.

"LogiqWorks provides the ability to take this data and intelligently and efficiently do something with it," Bresenham said.

Making 4D ultrasound routine will take some doing. There are problems with getting the data into PACS, she said. LogiqWorks will help in that transition, but it will not be enough.

"There is no DICOM standard for 3D ultrasound, as there is for MR and CT, so we have to create ways to get the data into PACS and still have access to the 3D information as raw data," she said. "It's kind of a dilemma right now."

A temporary work-around packages the volumetric data as "private objects" that can be stored in PACS. Pressing the case for better solutions is the expansion of volumetric capabilities on GE's Voluson 730 Expert. The scanner, which had been dedicated to ob/gyn, is now dressed out with two new 4D transducers. The pediatric probe broadens Voluson's reach to address neonatal imaging concerns. The company is enhancing its traditional capabilities with a 4D intravaginal probe.

Advanced processing algorithms pioneered on the Logiq 9 to improve image quality, such as inversion mode and speckle reduction imaging, which reduces speckle artifact, have migrated to the Voluson 730. They have also been incorporated into the company's shared services product Logiq 7, along with Crossbeam spatial compounding, which improves border definition, reduces acoustic artifact, and improves contrast resolution.

The software-based architecture, called TruScan, creates a common bond among GE ultrasound products. It takes over functions that were previously hardwired into the systems, allowing easier access to and processing of raw data.

"We have basically converted 50% of the machine into software," Ishrak said. "This has allowed us to begin our raw image data processing earlier in the chain than our competitors, which gives us a lot of flexibility and makes the migration of features easy now and in the future."