Hybrid Modalities, CAD Systems, and More: New Tech Trends for 2011

For a look at what major technology trends are on the horizon for this year, Diagnostic Imaging turned to two thought leaders: William G. Bradley, MD, PhD, who chairs the radiology department at the University of California-San Diego, and Jeffrey Weinreb, MD, professor of diagnostic radiology and director of medical imaging at Yale University School of Medicine in New Haven, Conn.

New Hybrid Modality Emerges

Without any communication between the two, each expert chose the same technology as the most exciting they’ve seen in years: Hybrid PET/MR systems, specifically the Siemens’ BiographmMR introduced at the Radiology Society of North America’s (RNSA) 2010 meeting in November.

As we described it then, the full-body PET/MR scanner, still awaiting FDA clearance, combines a solid-state PET camera into the isocenter of a 3T MR scanner, allowing simultaneous acquisition of MR and PET data. Philips Healthcare recently received European Union approval for its Ingenuity TF whole body PET/MR system, and is also awaiting an FDA decision. Meanwhile, GE is offering the ability to construct comprehensive images from data acquired during currently available MR and PET exams performed sequentially.

“MR is a very powerful tool on its own and the PET is a very powerful tool on its own,” said Weinreb. But both have limitations - the PET in terms of anatomic resolution and the MR in terms of metabolic function. “By merging these two technologies I think you’ll be able to not just have a symbiotic effect, but additive benefits,” he said. “It’s one of those technologies that is going to get people thinking about new ideas and open up some doors.”

The first of those doors, he predicted, will be in the brain because MR is, of course, already superior to CT for brain imaging. Following that will be cardiovascular uses and even breast imaging.

Nelson called the PET/MR the “big show stealer” at RSNA. “It will allow us to get a better handle on cross referencing MRI and PET abnormalities,” he said. He envisioned being able to perform high-end perfusion with the MR and correlating the results via PET, and predicted the new machine would stimulate the development of new PET ligands.

Older Tech Gets More Sophisticated

Nelson also predicted growing use of magnetoencephalography, or MEG, which uses magnets to track electrical currents in the brain. Although the technology has been around for years, it has not been sophisticated enough to allow for regular use. Newer technology, however, is strong enough to detect subtle changes in the brain, such as those resulting from concussions and other head injuries that would not be obvious on MRI.

Nelson said he sees the technology as particularly beneficial in diagnosing traumatic brain injury in veterans returning from Iraq and Afghanistan, and in tracking their progress during treatment. He also predicted it would find more use in evaluating brain damage after an ischemic event, particularly that involving injury the motor cortex. This could help provide important information as to whether rehabilitation is an option.

Weinreb also focused on a technology that is not really new, but that he predicted will gain increased use in the coming year or two: computerized diagnostic tools such as computer-aided detection (CAD) systems. “The applications and product offerings have expanded enormously,” he said. While they have been standard in breast imaging for quite a while, CAD systems are now being used for prostate and liver MRs, as well as neurologic applications, and to follow lung cancer patients with computed tomography (CT). Weinreb said he envisions today’s stand-alone CAD stations eventually disappearing as the technology is integrated into the radiologist’s viewing station, making it much easier to use in the daily work flow.

The first diagnostic radiology applications for mobile devices are also gathering momentum, he said. The FDA this month cleared the Mobile MIM application for use on an iPhone or iPad. The app enables physicians to securely receive radiologic images, view them, and make diagnoses based on CT, MRI, and even PET. The Mobile MIM application “is the next step in the evolution of teleradiology,” Weinreb said.

Another recent approval that got his attention? The first MRI-safe pacemaker, which the FDA also approved in early February. “Although this is not an imaging technology, it will affect an enormous number of patients,” he said, noting that approximately 70 percent of individuals with pacemakers will eventually need an MRI.

“Although you can do an MRI on pacemaker patients it is not an easy process and there are concerns about it,” he noted. While the Revo MRI SureScan, manufactured by Medtronic, still won’t allow direct cardiovascular imaging, it will allow imaging of areas above the cervical spine and below the thoracic spine. Weinreb predicted that such pacemakers will become the standard over time.

Another trend Weinreb said will gain speed is greater use of MR in the operating room. Although MR has been used for neurological procedures, “they are starting to come into their own” with expanded use for other surgeries, he said. Of particular interest is that more hospitals are installing 3T rather than 1.5T scanners, providing greater imaging potential.

This year will also see a greater development and use of low-radiation CT scanners, Weinreb said, after recent reports that Americans were receiving too much radiation from CT scans. This is particularly important in the emergency department, he said, where clinicians would like to order more CTs but don’t because of fears of radiation. Indeed, a study presented at the 2010 RSNA and published simultaneously online highlighted an increased use of CT in the nation’s EDs, but, in an interview, the lead author also predicted that radiation concerns, among other issues, “were likely to inhibit further growth.”

One way to reduce radiation exposure? Iterative reconstruction techniques, which Weinreb called “one of the hottest topics in CT.” Iterative reconstruction use mathematical algorithms to reconstruction images from a projection of an object, he explained. It allows the same image quality as a standard filtered back projection (FBP) but with a significantly lower radiation dose; or, the same radiation dose can be used to generate a significantly better image quality than with FBP alone.“As more complex iterative techniques are developed and refined, further reductions and better image quality will be possible” with less radiation, he predicted. This is an area in which all the leading vendors are developing products, he noted.

Finally, Weinreb praised recent efforts of manufacturers to make MR machines simpler to use. “All of the vendors recognize that getting the patient positioned in the scanner and performing the scan takes too long and results in too much variability due to differences in patient body habitus and ability to cooperate as well as technologist skill and experience,” he said, “particularly in complex exams. Now vendors are developing products to improve work flow by decreasing set up and scan time, reducing image quality variability, and facilitating complex studies.”