Ken Faulkner is on a huntnot for treasure, but for people in danger. Sound ominous? It is. Lots of people out there are at risk for osteoporosis, and they dont know it. We need to find them before they have a fracture. After someone suffers an osteoporotic fracture, the risk for a second fracture increases dramatically, so we really need to measure bone density earlier, explains Faulkner, who has been working in the field of bone density for almost 20 years and is chief scientist for GE Healthcare (Waukesha, Wis).
In determining who should be treated for osteoporosis, bone density testing is one of the most powerful clinical tools, Faulkner says. Forty percent of women over the age of 50 have low bone mass and arent aware of it. At GE, we are working with our customers to create a future without fracture.
To this end, the company recently introduced the Prodigy Advance, which uses dual-energy X-ray absorptiometry technology to calculate bone density with advanced detectors and a lower radiation dose. This newest product in the GE Healthcare bone density line also can determine total body fat, be connected to a PACS unit, and be used for pediatric as well as adult patients. The system guides the operator from the time of the patients entry to completion of the report, and advanced reporting features enable customized reports to be produced with a click of the mouse, Faulkner reports.
Toshibas Aquilion technology provides imaging of the heart and noninvasive follow-up for osteoporotic patients.
Although many radiologists are using the Prodigy, more than two thirds of users are nonradiologists, including orthopedists, obstetrician/gynecologists, rheumatologists, endocrinologists, and other specialists who treat women with osteoporosis. The Prodigy offers better measurements of the spine, with 40% to 50% better precision than any other system on the market and a 50% to 75% lower radiation dose, Faulkner says. In addition to precise bone density measurements, the vertebral fracture assessment technology allows for detection of an existing fracture of the spine in a single dual-energy scan.
GE Healthcare also offers the Duo and Bravo bone densitometers, which can double as examination tables. Because of their compact size and osteoporosis-screening capabilities, these products are especially suited to family practices and obstetrician/gynecologist offices.
Efficiency of CT Imaging
Investigators have begun to study a possible correlation between bone mineral loss and the formation of calcium deposits in womens heart vessels as part of the aging process. The beauty of computed tomography [CT] is that you can view the backbone to look for bone mineral loss and view the coronary arteries for evidence of calcium deposits, all in the same CT scan, says Robb Young, cardiac CT product manager for Toshiba America Medical Systems (TAMS of Tustin, Calif). CT calcium scoring is still somewhat controversial, however, because it is not yet reimbursable.
TAMS Aquilion technology enables imaging of the spine and hip, the two areas at greatest risk of fracture, in one CT scan, within approximately a 5- to 10-second breath hold. After the images are sent to the workstation, the bone loss is determined. Patients generally return for a follow-up scan within 6 to 12 months, depending on the severity of their osteoporosis, so that their progress with therapy can be checked. Now that the possible link between bone mineral loss and calcium in the heart is of interest, the capacity of the system for noninvasive follow-up and for imaging of the heart in the same procedure is vital, Young says.
Advantages of QCT
Roger Schulte, VP of sales and marketing at Image Analysis (Columbia, Ky), notes that two of the advantages of quantitative CT (QCT) are that it is reimbursable and it can focus on the trabecular bone, where the first evidence of response to therapy is seen.
GE Heathcares Prodigy Advance (right) offers the QuickView 10-second AP spine and femur image acquisition.
To that end, pharmaceutical companies have been using Image Analysis QCT bone densitometers with integral bone measurements to study response to drug treatments for osteoporosis. And according to Schulte, another advantage is that at Medicare reimbursement rates, most customers recover capital costs of the QCT in 6 to 12 months.
Looking to the future, we are expanding our background in CT calibration to refine coronary calcium scoring. The calcium scores of small versus large patients will differ, and calibration can minimize scoring errors, he explains. It is important to determine whether calcium in the coronary arteries is increasing or decreasing in a patient over time, and our QCT technology is being used for research in this area.
Advanced Viewing and Transmission Capabilities
AccuSoft Corp (Northborough, Mass) designs such products as the Image Transport communications system, which is used in the DICOM option of GE Healthcares axial bone densitometers. AccuSoft has been offering imaging products since 1985 that are embedded in a variety of applications, including Kodak picture disks, Lexmark printers, and picture uploading on a popular auction Web site, says Ian Lee, AccuSoft VP of engineering and customer services.
In 1996, the company entered the field with its ImageGear family of imaging tool kits that enable viewing of images from any modality. The tool kits provide key image-related capabilities in the VISTA information system for 75 Veterans Administration hospitals throughout the United States. The system allows physicians to view a medical record from a single computer application, without the need for any paper output, Lee explains.
According to Ken Cleveland of the AccuSoft sales division, the GE axial densitometers employing AccuSofts ImageTransport MD DICOM communications system are cost-effective for small practices. Clinicians can obtain digital images and have easy transfer cap-abilities without a lot of associated cost. Com-pared with an MRI scanner, the capital investment is low, and data are easily transmitted to the primary care physician, he notes. This is cutting-edge technology that improves patient care.
As GE Healthcares Faulkner puts it, Physicians and bone density technologists are always looking for more accurate and precise measurements for patientsalways smarter, faster, better.
Aubrey C. Patrick is a contributing writer for Medical Imaging.