by Aubrey C. Patrick
Companies in the bone density field are forever striving for more precise and accurate
measurements of bone density and general bone healthespecially in women, as 40% of
all women older than 50 are at risk for osteoporosis
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.