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Better Imaging Comes into View

Like other aspects of the military, medical imaging has undergone profound changes as a result of over a decade of conflict. For warfighters, the innovations implemented can pay life-saving dividends.

“We have almost a 98 percent survival rate. That happened because of surgical techniques, innovative blood products, fast and expedient air medical evacuation, and, of course, there came radiology,” said U.S. Army Lieutenant Colonel Mohammad Naeem, M.D., chief radiologist at the U.S. Army Regional Medical Center at Landstuhl, Germany.

Further advances should cut radiation exposure, make it easier to create images and improve productivity. This will be the case for fixed facilities and in-the-field operations.

One advance already in place has been the progression of CT, or computed tomography, from four to 64 slice scanners. Machines now can image the entire body in minutes, providing surgeons and clinicians with up-to-date and highly accurate assessments of a patient’s condition. 

Naeem noted that the Afghanistan conflict was the first to deploy MRI scanners in theater, a difficult task since the devices require sub-zero cooling and protection from electromagnetic interference. An MRI machine can provide a baseline scan after a traumatic brain or diffuse axonal injury, signature wounds of improvised explosive blasts.

What is more difficult to do is functional MRI, which captures brain activity. Teasing out that information takes a lot of image post processing and this cannot be done everywhere, according to Naeem.

The challenge of dealing with an avalanche of data also shows up in other areas. For instance, when U.S. involvement in Afghanistan began, imaging data generated in theater was written to an optical disk and shipped back, possibly delaying treatment. Scans also might be repeated, with the wounded undergoing one in theater, a second in Germany, and a third in the U.S.

The Joint Telemedicine Network now allows images to arrive at Germany and the U.S. before patients do. A dedicated network, it is designed to handle the transmission of the up to 2,500 or more multimegapixel images done in a single study. 

As for the future, this network and its successors can help the military deal with a constrained budget. The ability to ship data around the globe means that radiologists anywhere can interpret medical images. Potentially, this maximizes the use of radiologists and resources.

For their part, vendors are implementing innovations that should make imaging easier. For instance, Philips Healthcare of Andover, Mass., just launched Epiq, a new premium ultrasound system. It offers what the company calls anatomical intelligence. This embedded database harnesses machine intelligence to help make it easier to extract meaningful anatomical measurements from image data.

“Independent of who’s generating the quantification, you should get consistent results,” said Sean Gallimore, global vice president of ultrasound marketing. 

He added, “We’ve built rich databases into the system so they can recognize anatomical structures and generate measurements based on that recognition. The user can always override those, so it does not preclude clinical judgment.”

The first pass of this approach targets the heart. It can automatically determine where heart chamber walls are and the size of those chambers. Later versions of the software will extend this capability to other aspects of anatomy.

Besides incorporating machine smarts, the system also can image with greater clarity than older ultrasound systems. It more than doubles tissue resolution and improves penetration by 76 percent, Gallimore said.

The system pulls this off via precisely formed ultrasound beams and massive parallel processing. A standard ultrasound beam has an hourglass shape when transmitted, with the returning echo more pencil shaped. The new technology, in contrast, creates a pencil-shaped outgoing probe and receives a similarly shaped return. The result is a significant increase in imaging frame rate and time resolution, the company stated. Once
the signal is received, proprietary hardware and software execute 450 billion 40-bit multiply-accumulates per second, equivalent to the computing performance of 25 high-end gaming desktop PCs. 

In discussing the imaging improvement, Gallimore cited a highly challenging situation: imaging a fetus to look for the brain stem or retinal vessels. Both of these have been done with the new system, something beyond other ultrasound systems.

“The context is the baby moves, so you need a pretty high frame rate to capture that,” Gallimore said.

The system console and monitor are articulated for proper positioning. It is quiet and consumes 25 percent less power than an earlier generation of ultrasound machines. Finally, it is more portable, in part because at 210 pounds it is 40 percent lighter than previous premium ultrasound systems.

The system has a relatively small footprint, making it suitable for use in an emergency room or in theater. It also has a sleep mode, which cuts power consumption but still allows imaging within a few tens of seconds of the beginning of an exam, Gallimore said.

Its capabilities can aid surgeons and clinicians. For instance, the system can display multi-modal images, meaning that an ultrasound image can be seen next to an X-ray. 

“For surgeons who are used to two-dimensional angiograms but they’re getting an echo image, which is a volume image, you can actually compare the two,” Gallimore said.

From its headquarters in Twinsburg, Ohio, Hitachi Medical Systems America supports CT, MRI and ultrasound imaging solutions for a range of military and VA hospitals, imaging centers and clinics. The company offers products based upon very different approaches because each has strengths and weaknesses, and thus are best suited for different clinical objectives.

“MRIs are very good for looking at soft tissues and organs and things like that, but the scan time takes a little bit longer. CT is very beneficial in terms of looking at bone structures and things of that nature. It’s a very quick scan,” said Sheldon Schaffer, Hitachi Medical Systems America’s vice president and general manager for MR/CT.

The difference in speed can blur the neat separation between soft and hard tissue imaging. For instance, CT is often preferred for peering inside the abdomen, which moves rapidly due to breathing. The speed of the scan minimizes motion artifacts.

Hitachi has CT scanners that range from 16 to 128 slices. Going up in slice count allows clinicians to make two different imaging adjustments. They can opt to complete a scan in a shorter period of time. Alternatively, they can improve the resolution of the image and the detail that can be seen. No matter the choice, Hitachi’s products offer the latest in radiation dose conservation technology, minimizing patient exposure to ionizing radiation.

On the MRI front, Hitachi supplies proprietary open-architecture technology, such as in its Oasis line of products. Consequently, patients are not enclosed in a cylinder, Schaffer said. “It’s boreless. There are no sides to the MRI system.”

Systems built with this wide-open technology currently top out at 1.2 Tesla. More powerful imaging is possible with the company’s 1.5 Tesla Echelon. Even here, though, a wide-bore approach minimizes any feeling of confinement and maximizes patient comfort, according to Schaffer.

As for the future, Hitachi is working on several different fronts. Faster imaging and less expensive systems are two possible directions that will be taken. 

Better and more efficient data exchange are other innovations being pursued. Here, though, progress may be difficult, in part because the problem is not something any one company can fix. Patients go where they want and in the past, studies were not readily shared or accessible. How to read the data has been standardized by Hitachi and other medical imaging equipment vendors, but that is only part of the solution.

“In terms of managing or housing the information centrally, that’s something the physician community must work out,” Schaffer said.

Another imaging vendor with a presence in military medicine is San Francisco-based McKesson. The company offers radiology and cardiology solutions that go beyond ordinary image analysis. McKesson provides solutions that integrate with the electronic health record, thereby helping to provide access to the image data as it moves through the system. 

“Our solutions help facilitate the sharing of data, enhance care team coordination and provide efficient workflow,” said Matt Ward, a senior functional analyst. 

This is important given that active duty personnel eventually transition to veterans. All told, there are some 18 million patients, ranging from newborns to aging veterans, in either military or VA systems, according to DoD officials. 

McKesson’s radiology offering has been approved for clearance through the DoD Information Assurance Certification and Accreditation Process, and thereby has been certified to be secure. The company’s cardiology and study sharing products are in the process of approval, as is the McKesson Quality Intelligence & Communication System. The last of these is specifically designed to support quality initiatives and the extraction of information from a mountain of imaging and other data.

Speaking of large data volumes, the company has run tests of its system, which simulated the equivalent of an annual volume throughput of 5 million exams. That translates to some 1,600 studies per hour, Ward said. McKesson did this to prove that the system was scalable to these numbers and not because the company thought that all facilities using its products would see such volumes.

In general, all of the company’s solutions are optimized with respect to network performance, Ward added. The result could be faster launch times for applications and faster load times for the first image, important factors when volumes are high or care is critical.

A form of future proofing can be seen in the McKesson Enterprise Image Clinical Reference Viewer. It has no footprint on the client side and it is browser-agnostic. As a result, physicians can use it to access reports and images from desktops, laptops and mobile devices. 

“It provides a simplified and intuitive workflow available on a variety of desktops and mobile devices that will help reduce training, increase end-user satisfaction and enable fast adoption by referring physicians,” Ward said.

Melville, N.Y.-based Canon Americas is another vendor implementing helpful technology advances. Along with subsidiary Virtual Imaging, the company produces a range of digital radiography and fluoroscopy imaging solutions. Both involve X-rays, with fluoroscopy specifically for real-time moving images.

The military uses Canon’s 4kW Portable Radiographic System down range and also aboard the U.S Navy’s Comfort and Mercy hospital ships, said Sheila Gilmore, major account executive for federal accounts at Virtual Imaging. At 225 pounds, these portable systems are lighter than the fixed ones, which tip the scales at 1,200 pounds. The portable systems must be plugged in, whereas the stationary systems can be battery powered.

The smaller units have a maximum X-ray power output of 4.0 kilowatts. The comparable figure for a stationary unit could be as high as 80 kW. That difference translates into less of an impact on image quality than might be expected.

“Our RadPro digital radiography solutions with Canon digital detectors are refined as to the power and the lower dose so that you don’t need a lot of power to get a really good image,” Gilmore said.

Canon’s digital radiography detectors are up to 11.3 megapixels in size and convert incoming X-rays into a 14-bit digital image. Some versions wirelessly transmit data. 

These detectors are second generation digital devices. The first replaced film, thereby allowing direct storage in, transmission to and manipulation by computers. However, the dose increased perhaps 10-20 percent as compared to film. Also, the detectors were not the same size as traditional X-ray cassettes, requiring the revamping of radiography rooms.

“Now we’ve gone to the same size as the cassette for the digital part,” said Mark Anderson, Virtual Imaging product training manager.

As for the dose, the latest technology cuts it in half, making it a third or more—less than that for film. The greater sensitivity improves image resolution and the clarity of smaller details.

There’s a general trend to reduce patient exposure to ionizing radiation. In addition to more sensitive detectors and other hardware innovations, software and systems can also contribute.

For instance, when an order comes in for a particular image, the requirements are automatically populated by Canon software. Thus, for a wrist study, the system will know that typically three images are needed. Before any X-rays are taken, checks ensure that the right person is getting imaged and the right study done.

As images are taken, thumbnails pop up, providing an immediate quality check. They also lessen the chance of a mistaken retake. The software includes other capabilities that can cut down on the total dose. 

“There are reporting opportunities for different type of image rejects and retakes. We can track it pretty close, down to the technologist and to the room it’s been done in and the machine it’s been on. So if there’s an incidence of high repeats, they can track it and cure what the problem is,” Anderson said

Earlier this year, Canon’s digital radiography systems and its virtual imaging software received U.S. Air Force information assurance certification. This complete portfolio certification is a first in the industry, the company stated.

Information assurance is on the mind of Jim Bisenieks, product manager for clinical technologies at the U.S. Army Medical Research and Materiel Command at Fort Detrick, Md. His team implements systems to satisfy the clinical imaging requirements from field units and hospitals. The group gets involved when systems cost over $100,000, a category covering high-end ultrasound, CT, MRI and radiological systems. The team has a group that evaluates software and systems to make sure images can be transmitted without risk. 

“When we plug it into the wall to be able to save, send, receive and transmit those images, we want to make sure that the systems are as secure as possible,” Bisenieks said.

Some of the other characteristics that might be evaluated have to do with modifications made so as to allow imaging systems to operate in harsh environments. The list of conditions includes shock, dust and even some weather.

Other factors that are evaluated are what happens to the machines after they are delivered. For example, are technicians and parts on hand to fix a machine? Are monitors available to adequately display the data? Is secure bandwidth—or other means—available to move the images from the system to remote locations?

Given all of this, an expensive piece of equipment may not be the optimum solution. At times, a system based on an older but more easily supported technology is the best fit, Bisenieks said.

However, he noted that clinicians have the expertise needed to set requirements. When it comes to looming budgetary constraints, he noted that imaging advances can save money and improve outcomes. 

Bisenieks sees his job as making sure that the proper clinical tools are in the right hands. As he said, “As long as new diseases are being discovered and injuries occur, I’m going to fight to ensure these doctors and clinicians have the technology that provides the best outcome for the patients.” ♦

Last modified on Wednesday, 16 April 2014 12:46

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