Advanced Visualization and Mainstream Radiology: A Perfect Match
Advanced visualization is radiology’s latest oxymoron. That is, in many enterprises, 3D tools have entered mainstream radiology. Early adopters of next-generation advanced viz solutions report that 3D functionality is no longer difficult to access or reserved for specialized cases. Instead, these sites are deploying a universal, democratic 3D model with advanced visualization functionality available across the enterprise.Take for example the VA Maryland Health Care System in Baltimore. “Our philosophy is that as imaging grows more complex advanced visualization becomes an essential, basic tool. We use TeraRecon’s AquariusNET solution for nearly all clinical applications,” explains Khan Siddiqui, MD, chief, imaging informatics and body MR imaging. In fact, 96 percent of all CTA and MR studies are interpreted using AquariusNET. In the universal model, utility and access extends beyond radiology. Three years ago, the VA deployed AquariusNET enterprise-wide on all hospital computer systems, enabling users to access 3D anywhere in the enterprise. The investment paid off. Clinicians view a full 40 percent of imaging studies with advanced viz tools, says Siddiqui.
There are several ways to deploy advanced visualization across the enterprise. One option is the thin-client model, which relies on a central server for 3D processing. Images are processed on a central server that delivers 3D imaging to networked thin-client PCs. Other sites rely on the integrated PACS model with the 3D solution embedded in the PACS workstation.
Regardless of the route taken to universal 3D, adopters gain numerous benefits. Most importantly, this model addresses the double whammy of 21st century radiology. That is, it leads to improvements in both workflow and clinical care. It also streamlines and simplifies distribution and management of 3D images.
Despite its tremendous promise, the universal model is not without challenges. Advanced visualization means advanced technology, and it takes time and IT expertise to fully deploy advanced visualization. It also requires adjustment and training on the part of users. Neither issue is insurmountable; both can be overcome with clear planning and a solid vendor partnership.
3D: The clinical angle
The clinical rationale for enterprise 3D is clear. “The integrated 3D model allows us to quickly reach clinical decisions,” explains James Brunberg, MD, chair of radiology at University of California Davis (UC Davis) in Sacramento, Calif. For example, if a patient presents in the ER with a headache, he can be referred to CT. Within five to 10 minutes, the radiologist can review the reconstructed images to determine if the patient has a subarachnoid hemorr-hage. “We can view images on the PACS workstation and make an immediate decision about whether or not a contrast-enhanced angiogram is needed to detect an aneurysm,” continues Brunberg. UC Davis relies on Barco’s Voxar 3D integrated with Philips Medical Systems’ iSite Radiology PACS as its 3D solution.
Advanced visualization is particularly relevant in the new image-intense world of cardiac CT. “The CT process is very useful to rule out or rule in cardiovascular and peripheral vascular disease in both symptomatic and asymptomatic patients,” states Robert Schwartz, MD, medical director for Minneapolis Heart Institute Foundation in Minneapolis, Minn. Schwartz relies on Vital Images Inc. Vitrea software to create and navigate 2D, 3D and 4D images and rapidly assess vascular anatomy. “Vitrea helps us get the clinical job done while maintaining a high patient throughput,” sums Schwartz.
The widespread availability of 3D not only accelerates diagnosis and treatment. It also can eliminate other conventionally performed studies to hasten clinical decision-making and avoid the time and rigor of conventionally performed procedures like a cerebral angiogram. “In many cases, the 3D images meet our needs, and we no longer need to perform a catheter-based angiogram prior to surgery,” explains Brunberg.
VA Maryland Health Care has demonstrated improved diagnostic accuracy with its 3D program. Siddiqui explains, “Our internal studies show that radiologists can miss 19 percent of severe spine disease if they do not review a CT of the abdomen in the sagittal plane.” The thin-client model insures that the necessary functionality is available at the radiologist’s fingertips rather than at a separate specialized workstation, enabling users to rapidly render an accurate diagnosis.
3D efficiency in action
In the early days, advanced visualization represented a true workflow buster. Radiologists were forced to trudge to a separate, high-end workstation to perform 3D reconstructions. In addition to slowing workflow, the specialized workstation model drained financial resources as each workstation represented a hefty investment. Finally, images were not readily available for clinicians. Fast forward a few years — now it’s a very different story. The newest systems not only tackle workflow challenges but also improve workflow. At the same time, new solutions tend to be more cost-effective as they reduce and often eliminate high-end workstations. In this integrated/enterprise 3D world, radiologists don’t need to move to a separate workstation, wait for images to be pushed from PACS or communicate their needs to a 3D tech.
“Internal data shows that the average interpretation for a chest CT drops two minutes from seven minutes to five with AquariusNET,” reports Siddiqui. The ticket to these dramatic workflow gains is the live availability of 3D tools like MIP and MPR. “AquariusNET delivers 3D tools on the fly. They are right at our fingertips,” claims Siddiqui.
The integrated Voxar/Philips solution allows radiologists to access 3D images at the PACS workstation. “This is more efficient [than the separate 3D model]. Radiologists can maintain their concentration as they read various studies and shift from 2D to 3D. It takes 10 seconds to move from CT source images to the 3D dataset,” states Brunberg. Both the thin-client and integrated models streamline referring clinician workflow by making 3D images available throughout the enterprise.
Another integrated advanced visualization option is GE Healthcare’s AW Suite. Memorial Sloan-Kettering Cancer Center in New York City is one of the first adopters of GE’s PACS-based advanced visualization model and recently installed AW Suite on its Centricity PACS workstations. “This product fits our workflow,” explains Peter Kijewski, PhD, PACS project director. AW Suite is integrated into Centricity PACS, so studies do not have to be pushed between PACS and a stand-alone 3D workstation. Nor does the user have to move from a PACS workstation to a 3D workstation. Instead, users can select and activate a case on PACS workstation and access the same advanced functionality available on the stand-alone AW workstation. The new integrated model allows radiologists to access PACS tools, worklist, voice recognition and 3D on the same workstation.
The AW Suite model also makes it easier for users to access critical information. “As a cancer hospital, it’s important for our readers to view prior studies. These no longer have to be pushed to the radiologists or other users. Radiologists interpreting 3D studies also can view clinical history and the technologist notes on PACS workstations,” states Kijewski. Users who float between sites can access in-progress reconstructions regardless of which campus they are working from.
AW Suite not only enhances workflow but also trims costs and saves space by allowing the center to eliminate expensive stand-alone workstations, says Kijewski. Plus, the new model can be distributed. That is, as more users ask for advanced visualization functionality in their offices, AW Suite can be installed on the PACS work-station and the user is up and running.
Mastering technology
In the high-tech radiology arena, advanced viz solutions dominate many other systems. For example, synchronizing functions between Philips iSite PACS and Voxar 3D is somewhat challenging, says Brunberg. iSite contains an application protocol interface (API) that allows task-specific software like Voxar to interact with the base PACS software. The API does eliminate the need for the programmer to know the entire base operating system, but synchronization still requires fairly sophisticated knowledge. Voxar representatives handled the 3D integration at UC Davis; however, internal research staff has tackled other similar integrations. All report smooth operations now.
Other technical challenges relate to workflow. RIS integration can be spotty, making it challenging to read from a worklist and efficiently move from study to study, compare prior studies and review prior reports.
In addition, the sheer volume of multidetector CT images can slow any advanced visualization solution. Current generation hardware, graphics cards and storage capacity are stretched to their limits by these images and may not perform at the speed desired by end-users. Nevertheless, although image volume can push hardware and software to its limits advanced visualization software is quite useable, says Schwartz.
At the same time, education and training can be an issue. “Advanced visualization is a culture change for radiologists. They need to learn how to navigate data in a volumetric fashion without getting bogged down by thousands of images,” sums Siddiqui.
Future directions
Although it is careening into the mainstream, advanced visualization is still only in its infancy. There’s so much more to com. Today’s pioneers offer some insights into the next few years.
“Advanced visualization will become basic visualization. Physicians will demand these tools for everything, and all modalities will require technology to enhance images. We’ll see advanced visualization extend to tomosynthesis, CR and DR. For example, advanced visualization might be used to enhance a pneumothorax or a tube line to see its edge. In addition, 3D and CAD will be more solidly integrated,” predicts Siddiqui.
Brunberg foresees increased automation. Improved processors will allow 3D software and PACS to immediately present 3D datasets. New software will re-invent image review and allow radiologists to view slices in any obliquity.
Memorial Sloan-Kettering aims to place all imaging functionality on PACS workstations. “AW Suite covers 3D visualization and analysis extremely well, but more esoteric applications like spectroscopy are farther on the horizon,” notes Kijewski. The roadmap at Memorial Sloan-Kettering calls for SPECT/CT-PACS integration early in 2007. Next on the list is nuclear medicine functionality like cardiac analysis. “This will allow us to decommission more of our stand-alone workstations,” sums Kijewski.
Conclusion
Advanced visualization has come a long way — and is in a state of evolution. Advanced functionality is rapidly becoming a clinical essential, and users have demanded integrated, efficient solutions. Vendors are delivering an array of options to meet the workflow and clinical needs of the rapidly growing world of 3D end-users. Thin-client models and PACS integration can meet the clinical, workflow and economic needs of 3D users by providing the rich functionality at the desktop or PACS workstation.
The advantages are significant. 3D is universally available, which accelerates and improves clinical care. 3D and PACS functionality can be accessed at the same workstation to improve workflow and provide users immediate access to clinical information and prior images. On the economic front, sites can phase out and bypass expensive stand-alone workstations.
| Enabling Virtual Colonoscopy |
| Conventional colon cancer screening is a tough sell. Colonoscopy is an invasive procedure that requires a somewhat unpleasant prep, sedation during the procedure and even the thought of it makes a lot of people uncomfortable. Consequently, up to 85 percent of patients avoid screening, resulting in diagnosis at later, often more lethal stages. Virtual colonoscopy offers a new model. Patients undergo a CT scan, and a radiologist uses 3D software to create and fly-through a virtual model of the colon. Two years ago, South Texas Radiology Imaging Centers in San Antonio deployed Viatronix V3D Colon and implemented a virtual colonoscopy program. “Virtual colonoscopy volume has increased significantly,” reports Garrett Andersen, MD, director of virtual colonography. “V3D is our biggest marketing aid. Once we demonstrate a fly-through for a referring physician, he understands the value of the procedure and is very happy to send patients to us,” continues Andersen.  V3D includes a server and viewer that automatically build a 3D fly-through for review, streamlining virtual colonography and minimizing its impact on technologists’ workflow. On the clinical side, an experienced radiologist can review a normal study in eight to 10 minutes, says Andersen. In addition to post-processing and 3D review tools, the package incorporates a reporting tool; Andersen relies on the imaging center’s PACS to transmit a DICOM report to referring physicians. Practices like South Texas Radiology Imaging Centers find that adding virtual colonoscopy carries a number of benefits including increased CT utilization and increased revenue via the new procedure. In addition, patient care is enhanced. Unlike optical colonoscopy, virtual colonoscopy allows radiologists to view all abdominal organs and potentially identify other undiagnosed cancers. To capitalize on the benefits of virtual colonoscopy, sites need to evaluate various visualization solutions and deploy a system optimized for their readers. Andersen recommends that radiologists carefully consider their reading paradigm. That is, readers must determine whether 2D or 3D is the primary reading mode. Radiologists relying on a 3D primary mode begin the interpretation in 3D and refer back to 2D for confirmation or troubleshooting. 2D primary review operates in reverse; the reader begins with 2D images and reviews the 3D fly-through after 2D review. Other key factors in the decision-making process are user-friendliness and image quality. Virtual colonoscopy will continue to gain momentum as more physicians accept and understand the technology. And it will continue to evolve. “CAD is a reality,” confirms Andersen. “It’s very sensitive, which can be quite effective, particularly for inexperienced users. On the other hand, it can be confusing for inexperienced users. At this point, colon CAD is not quite ready for prime time. We need a new CAD algorithm that rids images of artifacts that are created when the curved surface of the colon is unfolded.” Like in other clinical arenas such as CT angiography, advanced visualization improves the clinical and workflow processes associated with virtual colonography by creating high-resolution 3D images for efficient and accurate review. In addition, the procedure is more readily accepted by patients. |