Some radiologists have relied on thin-client solutions as their primary advanced visualization tool for nearly a decade. Others are just discovering the benefits of thin-client computing that enables quick post-processing of CT and MR datasets and streaming to networked workstations. In fact, thin-client solutions for 3D reconstruction are hot. A number of factors are driving increased interest in and adoption of thin-client tools.

For starters, multidetector CT is nearly ubiquitous, and the massive datasets generated by 64-slice systems require 3D post-processing, which is bringing more facilities and healthcare enterprises into the market for a 3D post-processing solution.

The basic choice boils down to stand-alone workstations vs. thin clients or PACS integrations. The stand-alone workstation is a pricey powerhorse well-equipped to handle sophisticated 3D image manipulations and reconstructions. Vendors up the ante with an array of software packages tailored to specific advanced post-processing needs like cardiac viewing, virtual colonography and lung nodule analysis. On the downside, the workstation is a high-priced, fixed system that can accommodate a single user. What’s more, radiologists must break their PACS workflow to trek to the specialized workstation for 3D cases. 

Thin clients approach the 3D world from a different angle. An enterprise server processes CT and MR datasets and streams 3D images to networked workstations. Thin clients allow radiologists and other clinicians to view and interact with 3D images on PACS workstations as well as personal computers and laptops. Users do not need to disrupt workflow to move to a separate workstation, and 3D is widely available for the clinical masses like surgeons who want to view images. Other factors also drive increased acceptance of thin-client systems.

“Thin clients have progressed to the point where radiologists can complete significant post-processing on the thin client,” explains Mark Beller, MD, director of advanced imaging for Renaissance Imaging Medical Associates in Los Angeles. “It used to be a major undertaking to complete 3D MIP [maximum intensity projection] and MPR [multiplanar reformats] for a brain aneurysm. Now, those tools are available on the PACS workstation, which is a significant advantage. Other functionalities facilitate vessel analysis, coronary artery angiogram analysis and calcium scoring at the PACS workstation.”

The use of advanced tools translates into diagnostic improvements. According to Allen Elster, MD, chairman of radiology at Wake Forest University Baptist Medical Center in Winston-Salem, N.C., radiologists report an incremental yield of additional findings in the 20 to 25 percent range. That is, 3D tools help radiologists better detect pathology and diagnose complex injuries.

Finally, thin clients make sense from a cost perspective. A single proprietary workstation costs upwards of $100,000 or $100,000 per user seat, says Elliot Fishman, director, diagnostic imaging and body CT at The Johns Hopkins University School of Medicine in Baltimore, Md. A comparable thin-client solution may cost $200,000, but provides 10 licenses — dropping the cost of 3D post-processing to $20,000 per user.

This month, Health Imaging & IT examines thin-client solutions. Thin-client pioneers share the advantages and challenges associated with this approach. Think workflow, economics and patient care. It’s a recipe for success, and PACS and thin clients are primed to further penetrate the 3D market in the next few years.


The 99 percent solution

Beller spends 99 percent of his day reading studies on the Kodak Carestream PACS workstation, bypassing the practice’s stand-alone 3D workstation for the lion’s share of his cases. “3D post-processing is available with the click of a button, and streaming media downloads cases, even in studies containing 2,000 images, in a short time,” Beller says. As a result, Beller can read more cases in less time, a ‘tremendous’ improvement in workflow as the radiologist no longer travels between disparate workstations. Other efficiency improvements stem from the system’s progressive downloading capability. That is, images download by layers. The radiologist begins to interpret immediately as the first layer downloads. The balance of the dataset downloads in the background as the radiologist reads the case. The ability to avoid wait time is key in 3D cases as even short wait times add up over the course of a day. 

Beller points to another benefit of the current model. Carestream allows radiologists to open multiple cases simultaneously. If a physician phones Beller to review a case, the pair can discuss it. If the physician asks about a second case, the radiologist can open the second case on the fly and provide feedback to the physician. “Before this was a multi-step process. I would have to get the study number, hang up, recall the study and call the physician back,” explains Beller. The new model improves service to referring physicians. In addition, workflow is improved; if a radiologist is interrupted during the reading process, the software saves his place with the current study.

The final benefit comes on the patient care front. Because Carestream allows users to open multiple sessions, radiologists can readily access key prior studies to provide a thorough diagnostic review in a timely manner.

Denver Health Medical Center in Colorado employs a similar approach to its 3D program, relying on Emageon’s Enterprise Visual Medical System as its thin-client solution for 2D and 3D image interpretation.
 

Transitioning from workstations to thin clients

Wake Forest University Baptist Medical Center used to take the typical university medical center approach to 3D reconstruction. Independent 3D workstations were scattered throughout the center. As 3D demonstrated its clinical utility, demand for 3D applications grew, but it wasn’t economically feasible or practical to replicate workstations in every reading room, office, OR and ICU. “We realized we had to do something different,” says Elster.

The center decided to switch course and deploy a TeraRecon AquariusNET server two years ago. The transition has revolutionized the 3D program at the center. “It’s radically changed how we use 3D. We use AquariusNET rather than the stand-alone workstations for most 3D post-processing because we don’t need to import data or stop workflow to move to another station,” explains Elster. The system is integrated with PACS; radiologists pull up TeraRecon on a third color monitor. For bread-and-butter studies like chest and abdomen CTs, radiologists read from axial images and use multiplanar images to complete their interpretation.

The clinical impact of distributed 3D is significant, says Elster. “Radiologists see things they don’t anticipate when they have 3D views and additional planes. It helps viewers appreciate the complex anatomy.” A 3D reconstruction can provide an orthopedic surgeon with a detailed view of a complex fracture of the hip that might change how he approaches the surgery. Similarly, 3D helps users assess the juxtaposition of masses and organs and calculate tumor growth. Elster admits the addition of 3D can take a little bit more time than standard 2D review; however, the workflow impact is negated with the additional information 3D yields.

Given the proven clinical value of 3D, the medical center invested in multiple AquariusNET servers to provide 3D tools beyond radiology. Surgeons, for example, have a dedicated server for viewing 3D images to fine-tune surgical procedures. The approach also enables radiologists to complete 3D reconstructions from home using a VPN (virtual private network) or Citrix portal.


Reinventing the oncology conference

One of the primary advantages of thin-client 3D rendering is that thin clients distribute 3D across the enterprise. “The barriers to 3D post-processing disappear with thin clients [because everyone can access the tools]. It changes how physicians work in radiology and across the enterprise,” states Fishman.

The Johns Hopkins University School of Medicine uses an array of 3D reconstruction solutions including proprietary workstations and thin- client servers across the enterprise. One of the most clinically promising applications of the thin-client approach is the use of Siemens Medical Solutions’ syngo WebSpace thin-client solution to reinvent the oncology conference. “One of the primary problems in organizing multi-disciplinary conferences is getting images to the conference,” says Fishman. In the past, it was impossible for clinicians to review 3D images in conference as 3D workstations lacked portability. But thin clients bring 3D capabilities to the humble laptop.

syngo WebSpace is the cornerstone of the university’s weekly pancreatic cancer conference. Six patients arrive in the morning for a CT and lab work. In the early afternoon, radiologists, radiation therapists, pathologists, medical oncologists, surgeons and nurses meet to discuss cases. The specialists are able to review CT studies in 3D on the fly during the conference to determine whether the tumor is resectable. By the end of the day, the team has developed and shared a treatment plan with each of the six patients.

The benefits are multi-dimensional, says Fishman. Patient care is accelerated as all the relevant players can review images and options during the conference. “Plus, it’s a way of marketing 3D and increasing procedure volume as clinicians develop a better understanding of what 3D provides,” adds Fishman.
 

Future directions

Thin clients are hot right now, and their utility and value will continue to grow in the next few years. Pioneers look down the pipeline and predict coming advances.

The lines between PACS and proprietary workstations will continue to blur, predicts Beller. “I see PACS merging with the vessel analysis, PET/CT and cardiac packages that are limited to proprietary workstations now. One internet PACS will handle multiple interpretations from cine loops to PET/CT studies to wall motion.”

Fishman agrees and hints at the possible demise of the workstation. Currently, workstations enjoy a bit of an advantage because some functions like quantification tools are available only on the workstation. “Over the next year, we’re going to see more software packaged on thin clients,” predicts Fishman.

New graphic boards will drive faster, more accurate rendering says Elster. In addition, look for vendors to add more automated segmentation features to further simplify and streamline 3D post-processing.


Conclusion

As higher slice multidetector CT scanners and MRI systems have proliferated and penetrated the market, 3D reconstruction solutions have become an essential component in radiology and across the enterprise. More vendors are offering thin-client options for 3D reconstruction. The approach delivers a number of benefits: wide distribution of 3D viewing, lower overall costs and improved workflow. As more applications are made available on thin clients they could begin to dominate the 3D reconstruction arena.
 

Meeting the Needs of the Smaller Enterprise

3D is not a universal term nor is all 3D functionality universally available. Sophisticated 3D reconstruction packages that address specific needs like cardiac viewing may be limited to the stand-alone workstation or a PACS software upgrade; however, a number of PACS vendors are embedding basic 3D functionality like MIP (maximum intensity projections) and MPR (multiplanar reformats) into the PACS workstation. That’s good news for smaller hospitals and imaging centers because basic 3D options suffice for many cases, says Brian Singleton, MD, CEO of EagleEye Radiology, Inc. in Reston, Va. Eagle Eye Radiology uses Agfa HealthCare’s Impax 6.0 PACS. The ‘smart client’ system interacts with a server via web services to offer MIP and MPR functionality. “It serves 90 to 95 percent of our 3D needs,” states Singleton. The ability to reconstruct axial data into sagittal and coronal views in a matter of seconds provides radiologists with images necessary to diagnose appendicitis and evaluate ovarian masses and liver tumors. On the other hand, 3D volume rendering of an abdominal and pelvis CT can take 15 to 30 minutes. “The amount of time it takes to process these images into datasets inhibits its usefulness [in most cases],” says Singleton. Impax does provide additional 3D functionality via an integration with Barco’s Voxar 3D. The radiologist clicks on the Voxar 3D icon on the PACS screen to launch the 3D application; however, this software is reserved for complex cases like abnormal tumors or vessel identification in transplant cases. The downside of this approach is that the software must be loaded onto each workstation to be available across the enterprise, and the site is limited to the number of licenses purchased. Nevertheless, the thin-client model offers an excellent option for sites with smaller budgets and basic 3D needs. “The need for sophisticated volume rendering tools is diminished in smaller facilities, where most of the traumatic cases will be referred to tertiary centers,” notes Singleton. A thin-client PACS with basic 3D functionality and a single user license for advanced rendering often meets the clinical, financial and workflow needs of smaller sites. The upshot? Assess your needs, but don’t overdo it. It’s best to find a solution that can grow with the site rather than a solution that the site will need to grow into.

Evaluating Thin-Client Options

There is an array of PACS thin-client systems on the market, but not all are created equally. It’s critical to invest in a solution that will meet the facility’s need over the long haul. CT slice count will continue to climb. Make sure the PACS is equipped to handle the increased image volume, says Mark Beller, MD, director of advanced imaging for Renaissance Imaging Medical Associates in Los Angeles.   If necessary, educate others about the overall cost of ownership of thin clients and workstations. A single workstation may appear to be a bargain, but drastically limits the availability of 3D reconstruction functions. Thin clients distribute 3D to multiple simultaneous users.   The web-based system should provide access to the same reading functionality everywhere. Some solutions compromise functionality across reading stations. The same 3D tools and features should be available at every client. In addition, the system should not sacrifice image quality for convenience; radiologists won’t trade image quality for convenience.   Make sure a solution geared to enterprise users is easy to use, says Elliot Fishman, MD, director, diagnostic imaging and body CT at The Johns Hopkins University School of Medicine in Baltimore, Md. Training hundreds of enterprise users with varying degrees of computer know-how is a far more difficult task than educating a handful of computer-savvy radiologists and techs. Some systems are notoriously complex and require an entire shelf of manuals to complete reconstructions, says Allen Elster, MD, chairman of radiology at Wake Forest University Baptist Medical Center in Winston-Salem, N.C.   The thin client should run on a range of platforms including Apples and personal computers, so it is truly available across the enterprise.   Is the system economically scaleable, asks Fishman. Sites tend to start small, but 3D can grow rapidly. Adding an additional five, 10 or 20 licenses should be easy and economical.   Look for robust storage capabilities. Reading multiple 3D cases requires heavy duty storage with storage requirements rapidly escalating into the terabyte range depending on procedure volume. The solution should provide multiple simultaneous readers with a quality experience. That is, if a site buys a license for five seats, the system should meet minimum performance criteria for five concurrent users.   “3D should tie into a strong asset management plan,” advises Susan Proudfoot, administrative director of radiology at Denver Health Medical Center in Colorado. The enterprise should know when 16- and 64-slice CT will be deployed and plan for impacts on storage and other essentials like 3D post-processing technology.   “Know exactly what you need in a 3D tool, and specify it in the RFP [request for proposal]. Deploying 3D requires homework, site visits and strong planning. If a site starts weak, it will remain behind the eight ball,” states Proudfoot.