Deborah R. Dakins

I recently completed a task that we expect will lead to a more refined search engine for the Diagnostic Imaging Web site and those of our sister publications at CMPMedica. The project required perusing some 400-plus articles in the radiology literature from the past 30 years, covering every conceivable subcategory, and tagging those that best define each clinical application and modality. It involved some tedious parsing of wheat from chaff but provided ample opportunity for reflection on how far radiology has come.

Sifting through the abstracts prompted a bit of nostalgia. Since the mid-1970s, radiologists and vendors have discovered, investigated, and ultimately rejected multiple technologies and applications in their quest for the best. Xeromammography, dedicated rotational angiography, and biliary lithotripsy are all techniques that fell into the dustbin of history.

In addition to clinical practice, radiology vernacular has also evolved over the years. We no longer refer to "nuclear magnetic resonance" or "water-bath ultrasound." But some things don't change. Turf wars, self-referred imaging, and the goal of obtaining better reimbursement for services rendered were hot topics yesterday and remain so today. Just update the players (from chiropractors to cardiologists) and the applications (from in-office x-ray to self-referred CT angiography); the concerns and frustrations stay the same.

During this, the RSNA meeting season, when radiologists are deluged by new product introductions and applications research, it seems pertinent to reflect on the technologies that have come and gone, as well as those that have endured. In the past year, we've inked articles about diffusion-weighted MR for stroke, a new breast CT device, and SPECT/CT versus PET/CT. I wonder which of these we'll still be writing about in 30 years.

-Ms. Dakins is copy chief of Diagnostic Imaging.

Articles

Paging through radiology literature stirs remembrance of things past

In June, I had the opportunity to help with Diagnostic Imaging's online coverage of the Stanford Multidetector-Row CT symposium in San Francisco. This meeting is a perennial favorite of mine, peopled as it is by true believers who want to understand the nitty-gritty practicalities of CT while obtaining a big-picture perspective on what's next.

This is the meeting where little time is scheduled for breaks because there is just too much to talk about. These are the folks who wait three and four deep behind microphones to participate in highly interactive postsession Q&A debates. Last but not least, this is the conference that popularized the 3D workstation face-off, a four-hour marathon of mouse clicks and manipulations through varied clinical cases designed to demonstrate how workstations really work.

And there's always at least one presentation at the Stanford meeting that combines great content with outstanding delivery. In 2004, my personal "Best of Stanford" award went to Dr. David Yankelevitz of Cornell University, who made a compelling argument in favor of CT lung cancer screening. Last year, Dr. Larry Tanenbaum of Edison Imaging in New Jersey provided a cogent hands-on guide to neuroimaging with CT.

This year, a series of talks by Dr. Michael Lev of Massachusetts General Hospital on CT's growing role in stroke triage emerged as a winner. Lev's message, that all imaging is driven by clinical need, is particularly convincing when it comes to stroke. In this application, imaging has the potential to vastly expand the pool of patients eligible for treatment. In addition to his persuasive research, Lev's passion in delivering that message was inspiring. Sign me another true believer.

Ms. Dakins is copy chief for Diagnostic Imaging.

Stanford CT symposium makes true believer out of bystander

Digital mammography is more accurate than film in detecting cancer in women under age 50, those who have dense breasts, and in pre- and perimenopasual women, according to the long-awaited results from the Digital Mammography Screening Trial (DMIST).

The five-year DMIST trial, conduced with a $22 million grant from the National Cancer Institute, was conducted under the auspices of the American College of Radiology Imaging Network. The study involved 49,500 women and devices from four vendors, with initial and follow-up mammograms conducted at 33 sites in the U.S. and Canada. Study results were published online by the New England Journal of Medicine (www.nejm.org) and simultaneously announced at the fall ACRIN meeting on Sept. 16.

Industry watchers familiar with both technologies had predicted that the trial would be a draw in terms of cancer detection. And while digital and film did perform similarly in the total study population, digital proved statistically better in the three patient subsets. That finding surprised even Dr. Emily Conant, chief of breast imaging at the University of Pennsylvania Medical Center in Philadelphia and one of the study's coauthors.

"I think those of us who use digital knew it would prove to be better - we didn't know it would be significantly better," she said.

Conant noted that of the 49,500 women studied, about 65% fell into one of the three groups where digital excelled: under 50, with dense breasts, and pre- or perimenopausal. 

"That's a very high percentage, which says that digital mammography is valuable in detecting cancer in a large number of women undergoing screening," she said.

Digital has additional advantages over film. Digital images are easier to access, store, and transmit, and can be acquired at a lower radiation dose without compromising quality, according to the study. 

DMIST demonstrates that digital mammography is a "win-win," said Bob Britain, vice president of medical products at the National Electrical Manufacturers Association in Washington, DC. 

"Digital mammography improves cancer in key groups of women and allows improvements in productivity," he said.

Whether the study results will encourage increased adoption of digital remains to be seen. Digital systems cost about $450,000, and many breast centers are strapped for cash, given the low reimbursement rates they receive for exams. That hasn't deterred some sites from investing, however. In 2004, an estimated 410 digital mammography units shipped to U.S. customers, compared to about 200 in 2003.

"Cost remains a big factor," Conant said. "Individual sites will have to decide how much it is worth. But digital is the wave of the future, and this study is just the beginning."

Digital mammography finds more cancers than film in women under 50

When it comes to evaluating 3D workstations, the proof is in the clicks-the fewer the better. That's the consensus of attendees at a workstation face-off event held during the Society of Computed Body Tomography and Magnetic Resonance annual meeting in South Beach, FL, in March. 

In a showdown pitting workstations from GE, Philips, Siemens, TeraRecon, and Vital Images, imaging specialists navigated through five clinical cases ranging from cardiac to colon applications. Presenters, who had received raw data files in advance of the event, had five minutes to identify salient clinical details and display their findings using volumetric imaging tools. 

An audience response system allowed viewers to rank workstation performance on a per-case basis, providing proprietary information for vendors' eyes only, said Dr. Lincoln Berland, president-elect of the SCBT/MR and coordinator of the event. Audience members also ranked features that appeared most useful in manipulating and displaying individual cases. 

The ability to load and manipulate a case with as few mouse clicks as possible was the highest ranked workstation feature. This was closely followed by intuitive user interface, automation, clarity of screen layout, and availability of quantification packages. Other categories of import included curved planar reformation capability, image fusion, and cine features. 

Stanford University's Multidetector-Row CT meeting pioneered the workstation showdown concept. Such events have proved to be a popular way for radiologists to attain a real-world view of workstation performance. 

"People were transfixed by what was going on," Berland said. "They are coming here hoping for answers to questions like, 'What should I buy, and how do I use this thing? What should I be trying to create?' 

I think the information to answer those questions was readily available at the session." 

Such sessions also allow vendors to showcase new features and get peeks at how competitors' products work when put to the test. 

"Vendors take this exercise very seriously," he said. "I think all the vendors made substantial improvements to their software since the Stanford event (in June 2004). You can see lots of convergence in terms of capabilities between various systems." 

The big differences among systems remain processing speed, ease of use, and availability of specialized software for clinical applications. Dr. Shawn Teague, an assistant professor of radiology at Indiana University-Purdue in Indianapolis, demonstrated use of the Philips 3D workstation. 

"While other presenters essentially used their 3D card with volume rendering on every case, we were able to use specialized packages such as the one for virtual colonoscopy," Teague said. "Philips has a Filet View that curves as it pulls through, so you can see both sides of the colonic fold. Nobody else did that." 

To make that and other specialized clinical packages more valuable, vendors should make them available as tools, he said. 

"It would be more useful if you could call up a case and then decide which software application you wanted, instead of having to select the application and then pull up the case," he said. 

Dr. Michael Poon, chief of cardiac imaging at Cabrini Medical Center in New York City, demonstrated a TeraRecon workstation. Based on thin-client technology, the workstation server can be accessed from anywhere and does not require a dedicated, stand-alone workstation. 

In his presentation of a cardiac CT case during the face-off, Poon highlighted a feature that allows users to display a 3D image and overlay it with a 2D multiplanar reformatted image. 

"This is useful because if you see something abnormal in the 3D volume-rendered data, you can go straight to that image and create a 2D MPR," he said. "Other features that allow coronary vessel segmentation with the push of a button are also useful for those who are not as savvy with a mouse." 

Poon also took note of features on competing workstations, such as GE's vessel tracing software and its coronary plaque analysis package. Regardless of the vendor, such clinical offerings are of little use if the workstation simply can't handle data volume, he said. 