f02a.JPG (7975 bytes)Traditionally reserved for postmenopausal women and others who fall into a high-risk category for fracture, today’s increasingly sophisticated densitometry technology is branching out to include men, younger women, and children.

Bone densitometry—a measure of the bone mineral density (BMD) for the diagnosis of bone loss—is a painless, noninvasive test performed by either low-radiation dual energy X-ray absorptiometry (DEXA) or nonradiation ultrasound. Typically, a DEXA exam measures the spine or hip, whereas ultrasound uses sound waves to measure bone structure in the heel or shin.

The National Osteoporosis Foundation estimates that 80% of osteoporosis patients are women. Yet many medical professionals agree that early detection of bone loss for both women and men could help offset the morbidity that results in osteoporosis-related fractures. In fact, many healthcare leaders would like to integrate BMD much in the same way that checking a patient’s blood pressure is part of routine medical care.

With a range of equipment prices from which to choose, software packages to complement patient reports—not to mention increased recognition from Medicare and private insurance carriers—the business of bone health has never been healthier.

High-End Machines for High-End Testing
The new Prodigy Advance direct digital bone densitometer is the next generation in the Prodigy line, says Kenneth Faulkner, PhD, chief scientist for GE Medical Systems Lunar (GEMS Lunar of Madison, Wis). The Prodigy Advance promises to take “densitometry beyond BMD” with enhanced clinical applications, such as dual-energy vertebral assessment and advanced hip assessment, an increased table weight limit for patients up to 350 pounds, a feature that determines a ratio of bone and tissue composition, and a new pediatric measuring kit.

f02b.JPG (12941 bytes)The Prodigy Advance from GEMS Lunar claims detection of bone loss 40% sooner than comparable systems.

The pediatric measurement can determine whether some fracture-prone children suffer from a bone disease, growth disorder, or something else entirely. For example, prescription steroid medication for asthmatic children can sometimes “poison the bone,” Faulkner explains. This device allows doctors and parents to work together to strengthen children’s bone density through other preventive methods.

Body composition is another evolving field, Faulkner explains. The Prodigy Advance can perform a skeletal assessment to differentiate between fat loss and muscle loss. “Unexplained weight loss can affect bone loss,” he says. “We can tell you your percentage of body fat, bone, and lean [nonfat tissue], and we can monitor it over time.”

Hologic Inc (Bedford, Mass) offers the advanced Discovery series of bone densitometers, equipment that reviews bone density testing with a spine fracture assessment—a procedure performed in just 10 seconds. The Discovery models combine BMD testing with instant vertebral assessment (IVA), allowing evaluation of the two strongest risk factors for osteoporotic fractures: low bone density and existing spine fractures.

Patients who have suffered spine fractures are significantly more likely to suffer hip fractures or subsequent spine fractures, as are those who have low bone density, according to Eric von Stetten, PhD, VP and general manager of osteoporosis assessment for Hologic. With IVA, physicians perform an evaluation of the spine in combination with a routine bone-density exam.

f02b.JPG (12941 bytes)Norland’s CUBA Clinical is one of the industry’s first dry ultrasound systems.

“The benefits of IVA are that if you know both risk factors, you know a lot more about the patient’s risk for future fracture,” von Stetten says. “If you can look at both parameters, you can identify those patients at highest risk—those with low bone density and fractures—and you also can identify patients who might have had a spine fracture, but might not yet have low enough bone density to indicate treatment. Without the IVA capability, these patients are typically not offered treatment, in spite of the high risk for refracture.”

Cost-Conscious Alternatives
Hologic’s newest model of bone densitometer, the QDR Explorer, combines modern technology with today’s budget-conscious healthcare facility in mind. In addition to the electronic reporting capabilities, it comes equipped with an internal reference system, automated repositioning system, and dual hip imaging. It also features the QDR one-page report, which combines the image, scan analysis, and reference curves in a simple template format.

"For price-sensitive markets, where conventional bone-density testing is preferred over high-end imaging, Explorer offers the speed and precision of high-end systems at a price comparable to older-generation systems,” von Stetten says.

f02b.JPG (12941 bytes)Hologic’s Discovery System (below) boasts Express BMD technology, which provides regional hip and spine BMD results in 10 seconds with better than 1% precision.


Norland, a CooperSurgical Co (Trumbull, Conn), manufactures the McCue CUBA Clinical (Contact Ultrasound Bone Analyzer), a 22-pound machine that captures an ultrasound measurement of the heel in 1 minute. The CUBA measures bone density using velocity of sound as well as structural bone changes of the trabecular mesh using broadband ultrasound attenuation (BUA). With no computer hookup required, the CUBA can be used as an economical choice for stand-alone diagnosis and screening, or augment the traditional DEXA scanner with BUA.

Goodbye, Paper Trail
Paper-free, portable accessories are making new systems more appealing. The latest trends in bone densitometry are remote access capabilities and machines equipped with electronic reporting methods for the ultimate in convenience and efficient record keeping.

For example, GEMS Lunar offers TeleDensitometry, a software feature that can be used to print, fax, or e-mail reports from the densitometer. The Composer software produces the report. “The read back goes to the referring physician, and the interpretive report is automatically composed,” Faulkner explains.

f02e.JPG (14033 bytes)GEMS Lunar’s Dexter software provides paperless, remote review densitometry by displaying exam status and physician comments.

The company’s Dexter software transfers completed BMD measurements from the densitometer to a handheld PC. Patient results appear on-screen and include full-color values and graphs. Not only does this feature allow the physician to review the results remotely, but he also can add text or voice comments for the technologist. These processes can eliminate cumbersome paperwork and reduce potential communication errors, a boon for healthcare entities struggling to comply with the JCAHO’s 2004 National Patient Safety Goal 2—improving effectiveness of communication among caregivers. Each item is sold separately, although some packages do exist.

f02f.JPG (11849 bytes)More electronic reporting capabilities can be found with Hologic’s Physician’s Viewer and IVA Toolbox with CADfx, both of which are included with the new Discovery densitometer. Physician’s Viewer is a DICOM-based software package that allows remote review of BMD and IVA images. The CADfx—a point-and-click computer-assisted detection software—simplifies IVA interpretation by automatically grading spine fractures.

The optional Mobility software (includes two tablet PCs and a wireless network hookup) allows doctors to transmit images wirelessly to a tablet PC for reading at any remote location, and the optional Report Writer generates a Microsoft Word file that downloads biographical information, bone-density results, IVA results, and images. The file can then be sent to an administrative assistant, referring doctor, or hospital information system—with no transcription errors or printing involved.

The system limits what is tied to the scanner workstation, “allowing the reading physician to do reporting wherever, whenever they want to,” von Stetten says. “Discovery’s mobility feature streamlines workflow for physicians who do osteoporosis testing and makes reporting as easy as possible. That’s the goal of anyone, to be able to be at home working in front of a fireplace.”

Elaine Koritsas is a contributing writer for Medical Imaging.