New Imaging Machine Is Powerful Tool for Diagnosing Bone Disease
THE BONE QUALITY LABORATORY AT THE TONI STABILE Osteoporosis Center at Columbia has acquired a high-tech device that will help diagnose osteoporosis, a skeletal disorder characterized by compromised bone strength, predisposing one to an increased risk of fracture. CUMC now is one of three U.S. medical centers to house an Xtreme CT Scanner, a noninvasive machine that visualizes the internal structure of bones, offering information on bone density and quality that previously could only be obtained by a percutaneous bone biopsy. Though the Swiss-made device is more widely used in Europe, it came to the United States about a year ago and awaits FDA approval for clinical use. In the meantime, it is being used in three P&S studies.
“This scanner can be used as a predictor of who will fracture and could be used to evaluate many more people than a bone biopsy could,” says Elizabeth Shane, M.D., professor of clinical medicine in the endocrinology division and president of the American Society of Bone and Mineral Research. “It gives us more information than a bone biopsy because it provides us with a three-dimensional picture of the internal structure (microarchitecture) of the bones of the forearm and the lower leg. It allows us to see that different bones have different structures, why some bones of some people are stronger than others, and how various treatments affect the bone. We hope that this machine will help us detect patients who are at increased risk of fracture. ”
It takes about 30 minutes to complete the scanning process, Dr. Shane says. First, the patient’s forearm and lower leg are placed inside the machine for about 10 minutes each, while images of the bones are taken. Combining the high-resolution X-ray examination with computer programming to display slices of bones from different angles, the scanner reconstructs a 3-D picture of the bone that can provide information about bone health.
The machine cannot address the bone’s cellular activity as a bone biopsy would, Dr. Shane says, and also doesn’t replace the “gold standard” DXA dual-energy X-ray absorptiometry a machine that uses two X-ray beams to estimate bone density in the spine and hip. However, it could be used in an ancillary way to evaluate further the type of patient whose DXA scan falls between normal and osteopor osis.
Use of the Xtreme CT Scanner already has opened a new area of osteoporosis research, Dr. Shane says. A study employing a similar device at the Mayo Clinic, whose results were presented at the 2005 meeting of the American Society of Bone and Mineral Research, has revealed that bone loss occurs in both men and women between the ages of 30 and 40. It was previously thought that bone mass was relatively stable between those ages, since estrogen and testosterone levels hadn’t yet started to decline.
Other research activities using the device include an NIH-funded study of pre-menopausal women with unexplained low bone density, putting them at possible risk of fracture, and a study of hypoparathyroidism, which can lead to decreased levels of calcium in the blood. In addition, the machine is being used to assess fracture risk in patients with chronic kidney diseas e.
“We are very grateful to have this new state-of-the-art instrument,” says Ethel Siris, M.D., the Madeline C. Stabile Professor of Clinical Medicine and director of the Stabile Center. “We firmly believe that excellent research is the key to excellence in patient care. The Xtreme CT Scanner will expand research activity and address new questions about bone health, both critical steps toward the goal of reducing the human and economic costs associated with osteoporotic fractures.”
When a Kidney Mystery Must be Solved, the Renal Pathology Lab is the One to Call
A CONDITION CALLED NEPHROCALCINOSIS, CHARACTERIZED BY abundant calcium deposits in the kidney, is not something physicians commonly encounter. So when the team at Columbia’s Renal Pathology Laboratory received two kidney biopsies on the same day from patients suffering from it, they reviewed the patients’ medical histories for clues. Soon Vivette D’Agati, M.D., professor of pathology and director of the lab, had a “eureka moment.” She hypothesized that both patients had used the same oral phosphate-based bowel preparation before having colonoscopies, which in these patients caused calcium already in the body to precipitate as calcium-phosphate in the kidney, injuring the organ and leading to acute and, subsequently, chronic irreversible kidney failure.
Over the next few months, the lab discovered three more cases and published a paper alerting colleagues to their findings. Then Glen Markowitz, M.D., associate professor of clinical pathology and associate director of the lab, reviewed all of the lab’s kidney biopsy samples since 2000 more than 7,300 samples and found 21 cases that fit the pattern. The center published its findings in the November 2005 issue of the Journal of the American Society of Nephrology. Broad coverage in the news media followed, and the FDA issued a warning about the use of the phosphate-based bowel preparations.
This “diagnostic acuity, honed by a large experience,” Dr. D’Agati says, makes the lab a leader in its field. The lab’s four full-time pathologists interpret biopsy samples from more than 90 hospitals throughout the United States, then send detailed reports to and offer phone consultations with the referring nephrologists.
Dr. D’Agati was trained by the lab’s founder, the late Conrad Pirani, M.D., professor emeritus of pathology, who was considered one of the pioneers in the field of renal pathology. Dr. D’Agati started running the lab herself in 1984. As its sole doctor in the early years, she received and analyzed 350 biopsy samples per year. By the time Dr. Markowitz joined her in 1998, the lab was analyzing about 850 samples per year; this year the lab anticipates receiving 3,000 samples.
The sheer number of samples offers the team a unique perspective. “Because we receive such a large number of biopsies, we get to see trends as they are emerging, often before others are aware of them,” Dr. D’Agati says, adding that in the past five years, the lab has discovered several other drug toxicities affecting the kidney, identified a number of novel diagnostic entities, and spearheaded several major reclassifications of disease.
“When you get to aggregate this experience in one center and have four renal pathologists working well together, there’s tremendous academic power,” Dr. Markowitz says, adding that the lab publishes between 15 and 20 papers in medical journals each year.
The doctors also travel throughout the United States to conduct conferences and run the medical center’s longest-running continuing medical education course at Columbia, “Renal Biopsy in Medical Diseases of the Kidneys,” an annual four-day course that attracts about 250 participants from around the world.
“The medical center is lucky to have so much talent in the renal pathology lab,” says Michael Shelanski, M.D., Ph.D., the Delafield Professor of Pathology and chairman of the Department of Pathology. “They have the unique and valuable combination of being both excellent diagnosticians and teachers, which has earned them a prominence seen in very few such labs worldwide.”
Designation as Regional Perinatal Center Ensures High Quality Care
WHEN THE NEW YORK STATE DEPARTMENT OF HEALTH TURNED Aits attention to the health of pregnant women in 2001, it decided that the best way to promote healthy outcomes particularly for those with the most complex medical problems was to regionalize perinatal care. To ensure that medical centers provide a full range of services for pregnant women and their babies in a geographic region, the department invited major hospitals to apply to become regional perinatal centers. New York-Presbyterian/CUMC and 17 other New York hospitals were designated regional centers, and the New York State Assembly in September 2005 signed the Perinatal Regionalization Regulations to legislate the centers’ responsibilities.
For CUMC, which delivers about 3,600 babies annually, the designation is “an opportunity to bring together several disciplines from cardiology and neonatology to genetics and surgery at an extremely high skill level,” says David Bateman, M.D., associate professor of pediatrics and director of network nurseries. He adds that it also has paved the way for the development of Columbia’s Center for Prenatal Pediatrics, established in January 2004 to help pregnant women and their families when a significant birth defect or genetic condition has been found in their unborn baby.
A regional center serves both as a referral center for obstetric and neonatal complications, providing all aspects of obstetric and neonatal care, and as the hub of a network of affiliated hospitals to ensure a high quality of care. The regional center must be able to transport a patient from an affiliated hospital to its own facility in 30 minutes and ensure that in-house personnel are qualified to handle any emergency any time. It also must be able to provide pediatric cardiac surgery for which CUMC’s center is known less than 24 hours after a baby is born. CUMC receives 30 to 40 referrals per month from women with high-risk pregnancies who first arrive at an affiliated hospital.
“Women typically used to deliver their babies at community hospitals, and the most advanced care was more available at larger hospitals and medical centers. As care has become increasingly sophisticated, there has been a movement toward making that high level of care more available,” says Ronald Wapner, M.D., professor of obstetrics and gynecology and director of maternal fetal medicine in the Department of Obstetrics and Gynecology.
Each hospital in the state is designated by the Department of Health as a Level 1, Level 2, Level 3, or Regional Perinatal Center. This way, the department’s Web site explains, the facilities can focus on improving the skills needed for those services. Because the patients they see tend to be similar, they become more expert in delivering the appropriate care.
Dr. Bateman, Dr. Wapner, and Sally Girvin, coordinator of the Columbia regional center, frequently visit affiliated hospitals and review data (including the number of deaths, infections, use of medicines, and infant birth weights) to help assess the quality of care and learn about each hospital’s need for perinatal services.
“Because this is a new system, one of our focuses is on data collection to see how we can improve care,” Dr. Bateman says. “We offer protocols, consultative advice, and education with the goal of bringing about the healthiest outcomes.”