Although 3D rendering technology has existed for 20 years, it is just beginning to hit its stride. Facilities of all sizes and configurations are deploying an array of 3D rendering solutions to help radiologists navigate through the onslaught of data generated by today’s scanners. Cardiac CT angiography, which has skyrocketed with the advent of 64-slice CT, is driving adoption; however, other studies such as spine CTs and MR studies also benefit from 3D reconstruction technology.

While naysayers may peg 3D reconstructions as pretty pictures just for surgeons, 3D has become an important clinical tool, says John Warner, MD, radiologist and co-chairman, department of radiology at Marshfield Clinic in Marshfield, Wis. “3D volume-rendered images are essential for certain studies like MR angiography and complex spine cases. It makes the anatomy so much clearer and increases radiologists’ sensitivity and specificity for aneurysms [and other conditions].” What’s more, 3D may be cost-effective. “3D reconstructions could save money by eliminating unnecessary interventions or problems associated with less detailed and incomplete diagnostic information,” says Norbert Wilke, MD, chief of cardiovascular MR and CT services at University of Florida Health Center Jacksonville.

Facilities can choose from an assortment of 3D technologies and configurations. Stand-alone workstations provide the processing power to handle gargantuan datasets, and some functions such as coronary CT angiography post-processing and virtual colonoscopy may be available only on proprietary workstations. On the downside, stand-alone workstations can limit flexibility and disrupt workflow.

3D software, thin-client systems and PACS integrations provide greater flexibility and more readily distribute 3D technology across the enterprise. And 3D is invading the enterprise, too. “Radiologists aren’t the only 3D users,” says Steve Smith, PACS administrator at Alpena Regional Medical Center in Alpena, Mich. Surgeons, in particular, are turning to 3D for surgical planning, which means sites need a plan to distribute 3D functionality.

Another major issue to tackle is the 3D post-processing workflow. Who performs 3D reconstructions? Options include supertechs operating in a 3D lab. Alternately, radiologists can tackle the task and add it to their ever-growing to-do list, or a combination approach may best meet site needs.

This month, Health Imaging & IT visits with several sites to learn about their 3D programs. What software and hardware have been deployed? How are 3D tasks handled? And what are the benefits and challenges associated with the various options?


The 3D tech model

University of Florida Health Center Jacksonville has used and trained technologists and physicians on TeraRecon’s AquariusNET server and Aquarius workstation’s 3D rendering solutions. The university center instituted a 3D lab approach to reconstructions. “3D has become so prevalent that it has created a new job — the 3D post-processing technologist,” explains Wilke. The 3D tech is able to complete all post-processing for the radiologist; however, adequate training in anatomy, data acquisition and software applications is essential and must be taught prior to implementation.

The lab approach lets sites offer full 3D services, says Wilke. “It’s easier to train physicians to focus only on some specific applications they need rather than forcing them to learn all about 3D advanced post-processing functions. Relying on 3D techs reduces anxiety among physicians and opens the door to 3D imaging, especially if radiologists start with coronary or vascular MR/CT imaging.”

Whole body MR/CT angiography and cardiac imaging is patient-friendly and can be cost-effective in the long run. CT or MR angiography can be used to replace an invasive diagnostic test such as x-ray coronary or vascular angiography. The new option is brief, non-invasive and patient-friendly. “Imaging takes just a minute or two, and there is less risk to the patient. Plus, CT and MR angiography provide a full 3D/4D assessment of the anatomy and patho-morphological findings. Instead of looking only at the lumen of the vessel, CT/MR angiography helps the physician assess the vessel wall and measure plaque formation and atherosclerotic diseases at an earlier state,” notes Wilke.
 
Henry Ford Hospital in Detroit, Mich., also uses the 3D lab model. The lab and radiology department are outfitted with Vital Images Vitrea workstations, and three supertechs serve as the primary 3D staff, creating 20 to 30 images for each study and analyzing each vessel to provide radiologists with “pretty detailed” results, says Christine Nelson, leader, 3D diagnostic radiology.

Nelson cites several advantages to the 3D lab model. Radiologists can focus on reading and interpretation rather than reconstruction, while techs can take the time needed to focus on each 3D study. In addition, Nelson reports that clinicians and specialists tend to refer to 3D images more than radiologists. In cases where the radiologist or clinician prefers to complete some rendering or needs additional views, Vitrea does enable a fluid approach. That is, after a tech creates a snapshot, the image can be re-loaded onto any Vitrea workstation, and a new user can continue to work with the study from that point. 


Software and thin-clients drive integrated radiology workflow

The 3D lab/supertech model is most applicable for coronary imaging, but most 3D studies can be handled by radiologists with a minimal impact on workflow, says Marshfield Clinic’s Warner. Marshfield Clinic relies on radiologists for most post-processing; the clinic’s protocols call for techs to complete some basic post-processing such as multi-planar reformats (MPR) for body or spine studies to save some time. Radiologists complete additional 3D reconstructions on an as-needed basis.

“We incorporated 3D rendering into the radiologists’ workflow when we first deployed 3D in the 1980s,” recalls Warner. Early 3D programs were very labor-intensive and clunky, but in the late 1990s Marshfield Clinic deployed Barco Voxar 3D. Voxar 3D is based on a software-only approach; the clinic invested in six licenses and installed the software on PCs in MR and CT reading rooms, allowing the site to avoid the disadvantages associated with stand-alone workstations. “Radiologists were able to incorporate 3D into workflow on a routine basis. For some, 3D has become the primary image review tool,” explains Warner. That is, the reader opens Voxar as they review the exam.

The Voxar model is a thick client that requires installation on each computer. Marshfield Clinic plans to complement Voxar with new workstations and a thin-client deployment this spring. The clinic is adding a Siemens Medical Solutions Definition dual-source CT scanner and needs a system to handle CT angiography post-processing. The answer is a combination approach — TeraRecon’s Aquarius workstation and AquariusNET server. “We need the workstation because some functionality such as coronary CT angiography reconstruction and colonoscopy rendering is available only on the workstation, but most routine 3D renderings will be handled via the thin client,” says Warner. By the end of the year, the clinic expects that all 3D tools will be available via the server.


Real-time cardiac rendering

The University of Mississippi Medical Center in Jackson employs a vendor-agnostic approach to its 3D program. The center relies on a host of solutions. Barco Voxar 3D, 3D Enterprise and CardiaMetrix are integrated with Philips Medical Systems iSite PACS. GE Healthcare’s Advance Workstation (AW) is equipped with a host of software like Volume Analysis, CT Perfusion and FuncTool for a robust stand-alone option. And the center plans to deploy Siemens Medical Solutions syngo workstation later this year.

The center looks to use the Philips/Voxar integration as a springboard for real-time cardiac rendering program. “We want to use CT angiography as a marketing tool,” explains David Derr, MD, radiology informatics medical director. After patients are scanned on one of the site’s two 64-slice CT scanners, radiologists will reconstruct the images in the control room and immediately review the results with the patient. “Patients love it because we can show them a picture of the problem,” says Derr. Workflow, however, can be a challenge. “As with any medical test, the process works more smoothly with healthier patients. We have to [develop processes that allow us] to remain flexible,” notes Derr.


3D and the small, rural environment

Alpena Regional Medical Center is a typical small, rural hospital. The 154-bed hospital is a geographically-isolated site that serves six counties in northern Michigan. Like many similar facilities, Alpena is leapfrogging some early adopters when it comes to technology acquisition. The site deployed Kodak Carestream PACS, and a 16-slice CT in 2004. The goal, says Smith, is to offer better diagnostic care close to home. PACS-embedded 3D functionality helps the regional medical center meet its goal.

The center’s radiologists rely on Carestream workstations for an array of 3D functions including spine reconstructions and CT angiography. The center also plans to add cardiac scoring via Carestream later this year. Exam distribution and workflow is streamlined, says Smith. After a user saves 3D reconstructions, the images become part of the exam and can be viewed online. Prior to PACS, the medical center assessed its network for bottlenecks and decided to upgrade switches and change from copper to fiber lines to provide the bandwidth and speed needed to transmit images to outlying clinics as far 70 to 80 miles from the main campus.

The Kodak PACS has allowed the hospital to differentiate itself, and later this year, the center will tap into new capabilities to improve 3D throughout the enterprise. The current version requires a diagnostic workstation loaded with 3D capabilities, but the newest version of Carestream PACS will enable volume rendering over the web. Smith predicts that the site’s surgeons will embrace 3D for surgical planning.


Conclusion

3D is ubiquitous; it is an essential tool in radiology and across the enterprise. Physicians require 3D-rendered datasets for a wide array of studies to provide top-notch diagnosis and treatment. Sites can opt from a variety of solutions and implementation models, with many deploying a combination approach that mixes 3D workstations and software and workflow models.
 

3D Rendering in the Mega Cardiac Enterprise

University of California Irvine Center for Cardiovascular Imaging and Research is a cardiovascular CT behemoth. The imaging center provides training and credentialing in cardiac CT and reads about 50 cardiac CT cases weekly. The challenge, says Swaminatha Gurudevan, MD, director of cardiovascular CT, is that the 10 readers in each training course need simultaneous access to the data in each cardiac CT. The system must push a gigabyte of data per second, says Gurudevan. The center obtains gigabyte-per-second transmission from CT scanners to the classroom via a gigabit network connection and gigabit switches. Vital Images Inc.’s ViTALCardia provides the primary 3D review system. ViTALCardia allows users to assess multiple phases of the scan and complete the case in 20 to 30 minutes. Readers begin with coronary artery calcium scoring, which takes about 15 to 20 seconds. The next step, left ventricle functional analysis, requires two to three minutes of post-processing. Finally, the CT coronary angiogram analyzes the left and right ventricle for the presence and severity of coronary artery disease. Sites can select from several cardiac CT software and hardware packages to handle cardiac CT imaging, but the reconstruction solution is just one part of the equation. Gurudevan says a successful deployment hinges on a variety of factors. For starters, the site must be ready to handle and transmit cardiac data. “Users need powerful hardware with a lot of memory and processing power to handle 1,200 to 1,400 images in cardiac CT datasets,” says Gurudevan. Indeed, cases can stretch into the 2,000 image range. On the transmission side, a fiber-optic connection can provide the necessary speed, but often requires re-wiring. Ten-gigabit Ethernet would be ideal, says Gurudevan, but most computers aren’t equipped to handle data at that rate. On the viewing end, software should be user-friendly and portable to accommodate a wide range of users and platforms. PACS or a DICOM server for storage is another essential, and the site needs to develop a system for distributing results to referring physicians. Cardiac CT is driving 3D adoption and requires a fine-tuned 3D rendering solution that handles the nuances of cardiac studies such as calcium scoring and coronary CT angiography. In addition, facilities need to lay the groundwork for a successful deployment. PACS or a DICOM server is essential, and the network and hardware must suffice for hefty cardiac CT datasets.