Applied Radiology

This column highlights some of the magnetic resonance (MR) news from the84th Scientific Assembly and Annual Meeting of the Radiological Society ofNorth America (RSNA), held December 1998 in Chicago.

Magnetic resonance (MR) may be useful as a guide for laser-heat ablation ofbreast tumors. In a study presented at the RSNA of 15 patients, physicians usedMR to monitor placement of a needle and optic wire in the tumor. "Prior toablation, tumors look like bright stars in a dark sky. The laser heat spreadsin a sphere and the image turns dark when the tumor is destroyed,"explained Steven Harms, MD, professor of radiology and director of imagingresearch at the University of Arkansas for Medical Sciences (Little Rock).

"Because we don't make an incision, there is no scar and virtually noevidence of surgery. It is early, and more studies are necessary, but it is avery promising alternative for women who want to avoid disfiguringsurgery," said Dr. Harms. In this study, all patients underwentconventional treatment-either lumpectomy or mastectomy. Pathologic studies ofthe laser lumpectomy zones confirmed that all MR-identified tissue targeted bythe laser was destroyed.

Orthopedic and extremity MR

Siemens Medical Systems, Inc. (Iselin, NJ) introduced the MAGNETOM Jazz(figure 1), an open MR scanner dedicated to orthopedic imaging designed tohandle extremities, such as the shoulder, knee, ankle, wrist, and elbow.According to the company, twenty percent of MR imaging performed today isextremity MR. Designed to fit into a 194-square-foot room, the system weights2.2 tons, allowing for upper floor installations. The system comes with an RFshielding pavilion, can be plugged into a standard electrical outlet, andrequires no air-conditioning or water-cooling, according to Siemens. TheMAGNETOM can complement a whole-body MR system with a high patient backlog,said John Pavlidis, MR division manager at Siemens.

Lunar Corporation (Madison, WI) introduced the E-SCANTM Open Extremity MRsystem, which merges the features of extremity MR imaging with an open design(figure 2). E-SCAN can serve as a second MR system in radiology departments, oras the only MR system in clinics that cannot support a whole-body MR scanner,noted Bill Conn, MR marketing manager at Lunar. With a 0.2-Tesla permanentmagnet, the system fits into a 12' X 12' (144 square feet) room. Typically, itsmagnetic field requires no shielding, according to Lunar, and the system plugsinto a standard electrical outlet. The company estimates that imaging sevenpatients per week provides the break-even point regarding the cost of E-SCAN.E-SCAN received marketing clearance from the U.S. Food and Drug Administration(FDA) in July 1998, and the company expects to start shipments in the summer of1999.

Lunar also introduced Network PlusTM, a software package for ARTOSCANTM andARTOSCAN MTM (figure 3). The software includes a Netscape® web browser fordirect connection to the internet. It also enables users to create their ownweb pages and send images via e-mail. Both the ARTOSCAN and E-SCAN aremanufactured by Esaote Biomedica (Genoa, Italy).

Siemens expands MR into the OR
with swinging tilting table

MR-guided surgery may seem like a dream for surgeons, but it can pose alogistic nightmare with moving the patient out of the imaging room and into theoperating room (OR). Even in places where patients can have their MR in the OR,they usually have to be removed from the imaging table once the operationbegins. A new swinging and tilting MR table from Siemens, though, may reduceall that hassle. Designed specifically for the OR, the table swings out,allowing the surgeon to operate at the 0.5 milliTesla fringe field with360-degree access to the patient. The table also can change height and tilt,allowing gravity to position organs in the best location for routine surgery.The Siemens OR Open MR System was shown at the RSNA as a works-in-progress andis currently in use at the University Hospitals of Cleveland. According toJonathan Lewin, MD, director of magnetic resonance imaging at the institution,"The availability of rapid and simple OR table positioning and tiltingallows the physician to combine familiar and safe surgical orminimally-invasive approaches with the unparalleled image contrast and anatomicdetail provided by MR imaging." The table rotation places the surgicalpatient in the magnet within seconds, said Dr. Lewin, while still allowing thesurgical site to function far enough away from the magnet to use standardinstruments, x-ray, and ultrasound.

"Moving bed imaging" for peripheral MR
angiography

Philips Medical Systems (Best, The Netherlands) demonstrated "movingbed imaging" (MobiTrak), which automatically moves a patient through thePhilips Gyroscan MR magnet while the system acquires stacks of coronal images.According to Philips, the procedure provides MR angiograms from the aorta tothe feet, and makes it unnecessary to repeatedly reposition the patient."Angiography is the fastest growing application in MR," said JacquesCoumans, global MR marketing manager at Philips. The company believes that withMobiTrak technology, MR can replace many diagnostic x-ray procedures used todayin peripheral angiography. A typical examination can be completed in 30minutes, according to Philips, making peripheral angiography a true outpatientprocedure and eliminating overnight stays in hospitals. MR protocols availableon the Internet Philips also demonstrated its MR Protocol Navigator, a libraryof imaging practices available on the Internet. Radiologists and technologistscan view sample images of anatomy and customized guides for using newprotocols. Philips' partners, which include radiology departments at medicalcenters, contribute to MR Protocol Navigator, which also assists radiologistsduring diagnosis. Hospitals, clinics, and imaging centers that may ordinarilyrefer patients with complex diagnoses to larger medical centers can handle thecases themselves with online access to MR consultations, explained the company.

"We began using the MR Protocol Navigator as a reference primarily forMR angiography and musculoskeletal studies. Comparing MR imaging techniquesfrom other sites has helped us create our own MR protocols," said JamesJing, MD, staff radiologist at St. Luke's Episcopal Hospital (Houston, TX). Toregister for a free sample of the ser- vice, visit www.pmsna.com/gyroscan, orcontact a Philips representative.

MR installed in the ER

Picker International (Cleveland, OH) announced that it has installed itsfirst emergency-room (ER) MR system, a mid-field 0.5-Tesla Apollo, at theUniversity of Utah Medical Center (Salt Lake City). According to Picker, thissuperconducting whole-body MR system has a compact design that makes it apractical choice for smaller general hospitals, and in specialized applicationssuch as those used in the ER. To date, MR scanners have not been standardequipment in a hospital ER, but "they are proving their clinical efficacyin ER-type cases," said the company, "particularly in time-criticaldiagnoses such as head trauma, head-and-neck injuries, and orthopedicinjuries."

Open MR: Fifty percent of new system sales

"With open MR technology accounting for 50% of new system sales, it isclear that patients and clinicians are driving the acceptance of open MR sothat studies previously conducted with high-field systems are moving to opensystems," said Steve Sickels, director of the MRI Business Unit at ToshibaAmerica Medical Systems (Tustin, CA). The company introduced new features andsoftware for its OPARTTM, "the only superconducting 0.35-Tesla,cryogenless, open MR system available today," according to Toshiba.

Features with the Performance Plus Option will include advanced gradientcompensation control (AGCC) water-fat separation and echo mapping, and thinnerslice fast-spin echo (works-in-progress). In water-fat separation imagingstudies, the sequence is based on the chemical shift between lipids and waterrather than on relaxation differences associated with inversion techniques.This method, explained Toshiba, will be useful for fat-suppressed orbits,joint, breast, and contrast-enhanced imaging applications.

For its high-field 1.5-Tesla VISARTTM system, Toshiba announced aworks-in-progress software package that will offer new sequence featuresincluding diffusion-weighted imaging for stroke detection, cardiac tagging forcardiac imaging, functional MR for dementia-related disorders and surgicalplanning, and cardiac and respiratory gating.

MR fluoroscopy

GE Medical Systems (Milwaukee, WI) announced real-time interactive (RTIA)imaging for its MR product line. Sometimes called "MR fluoroscopy,"real-time MR "represents a paradigm shift in MR imaging," said thecompany.

"With RTIA, doctors will no longer request a 'one size fits all'imaging series," said Gene Saragnese, GE's global general manager for MR."Instead, an exam can be adjusted in real-time, as the image changes, tofocus on a condition specific to the patient."

According to Peter Black, MD, neurosurgeon-in-chief at Brigham and Women'sHospital (Boston, MA), the GE technology for real-time interactive imaging"adjusts the exam to the patient instead of positioning the patient toaccommodate system limitations." For example, "If a patient complainsof pain during a particular motion, RTIA allows the physician to capture whatis happening during the motion," said Dr. Black.

GE said it expects RTIA to be used widely in MR imaging of the heart, bloodvessels, bowel, and joints in motion (i.e., kinematics); functional brainimaging; and MR-guided surgery and intervention.

The company also introduced enhancements for its Signa® Profile/i openMR system. "The market for open systems has seen tremendous growth in thelast couple of years," said Mr. Saragnese. The enhancements includediffusion imaging with a new head coil, a complete interventional package, anew water-fat separation technique, and dynamic kinematic joint imaging.

"Diffusion is the most powerful pulse sequence ever available to theneuroradiology community," said Lawrence N. Tanenbaum, section chief ofMRI and neuroradiology at the New Jersey Neuroscience Institute, JFK MedicalCenter (Edison). "The availability of diffusion on Profile/i is criticalto making open MR scanning available to the large and important patientpopulation suffering from transient ischemic attack (TIA) and stroke,"said Dr. Tanenbaum.

MR head reference system

AnatoMark Systems (Lexington, MA), a division of InterneuronPharmaceuticals, introduced the AnatoMarkTM Head Reference System, a devicethat enables MR technologists to quickly align scans for patients who needrepeat brain imaging to evaluate tumors, multiple sclerosis, stroke, andseizure disorders. "The device is completely noninvasive, unlike manyother stereotactic reference systems that may require surgical attachment to apatient's cranium," said the company. Developed by radiologists at Brighamand Women's Hospital, the device also enables coregistration between MR andx-ray computed tomography (CT) scans.

Java-based software creators and Internet companiesinvade radiology

The picture of the radiology vendor community is undergoing a dramatic shiftas Java-based software creators and Internet companies continue to invade theRSNA exhibit hall.

Sun Microsystems, Inc. (Palo Alto, CA) announced "significant"enhancements in its JavaTM technology to better support the advanced imageprocessing used by medical imagers and radiologists. The enhancements includesupport for static gray visuals (256 shades of gray), fast lookup and retrievalof 8- and 12-bit images, and an early access version of the Java AdvancedImaging (JAI) Application Programming Interface (API) object library. The JAIAPI is a network-centric imaging framework that is "secure,platform-independent, and scalable across the entire healthcareenterprise," according to Sun. To download an early access version of JAI,visit www.sun.com/java/products/java-media/jai.

"We view Java technology as a strategic component in future imagingsolutions," said Peter Steven, chief technology officer of DOME ImagingSystems, Inc. (Waltham, MA). Dome plans to add Direct Graphic Access (DGA)support for Java technology in its product line.

Java-based software brings PC-based filmless
technology to small practices

A new company, Softmedical (St-Laurent, Quebec, Canada), introduced personalcomputer (PC) software that provides "the economical filmlesssolution" for small- to mid-sized radiology clinics and private practices.PCPax is archiving and visualization software that gives users flexibility in amultivendor environment. The company also offers Ubimed, a "scalablesolution for image and medical data distribution within and outside thehealthcare institution," explained Nadim G. Assi, president and managingdirector of Softmedical. Both PCPax and Ubimed are 100% Java-based andcompletely platform-independent, which means that any existing network PC canbecome a diagnostic workstation, minimizing an investment in hardware,explained Mr. Assi. The open architecture allows for complete integration ofequipment from different vendors. "Our software is based on client/serverarchitecture with a very thin client that can be downloaded, when needed, as anapplet. The client also can be installed on the user's station, eliminating theneed for a web server. In addition, our software can function just as well onthe physician's laptop computer as on the clinical desktop PC or the hospital'scomputer network," said Mr. Assi. For more information, visitwww.softmedical.com.

WAM!NET Inc. launches WAM!NET Medical

WAM!Net Inc. (Minneapolis, MN)-a company that provides graphic arts digitalnetworking and storage services for such clients as Time Inc., J.C. Penney, andWalt Disney Co.- just launched its WAM!NET Medical division. The new divisionoffers an offsite, online digital image archiving and transmission service forPACS (picture archiving and communication systems) users.

"This turnkey solution offers hospitals with full-scale and/ormini-PACS a comprehensive, easy-to-use service that complements their existingPACS by providing long-term, scalable, and redundant archiving," said GaryJader, vice president and general manager of WAM!NET Medical. "And becauseWAM!NET Medical is a service, customers only pay for the storage they use.There's no hardware, software, equipment, or phone lines to buy, and no majorinstallation, obsolescence issues, storage, or space limitations," saidMr. Jader.

According to Philip A. Templeton, MD, professor and chairman, Department ofDiagnostic Radiology at the University of Maryland Medical System, "WithWAM!NET, one would pay only for the storage actually in use at any given time,and you can get more whenever necessary without having to buy any equipment orlease space. Furthermore, there is no more concern with transferring patientfiles to new storage technologies when current technologies become obsolete, asthis would be managed by WAM!NET."

The system is now being tested at Waukesha Memorial Hospital (Waukesha, WI)."We wanted a solution that would give us redundant, offsite storage fordisaster recovery and back-up image accessibility while not changing ourcurrent PACS workflow. WAM!NET turns a big ticket budget item into acost-effective monthly expense," said Briant Redmond of Waukesha MemorialHospital. For more information, visit www.wamnet.com.