Marjorie Preston

A novel MRI technique that tracks naturally occurring polymers in cartilage can lead to the diagnosis of early-stage osteoarthritis and may lead to better drug treatment and a reduction in the need for joint replacement surgeries.Researchers from the NYU School of Medicine and Tel Aviv University have found that decreased concentrations of glycosaminoglycan (GAG) reliably predict the onset of degenerative joint disease in its earliest stages, before patients become symptomatic. GAG is recognized as a biomarker for both osteoarthritis and degenerative disc disease, which causes lower back pain. "By monitoring GAG, one can intervene much earlier in the disease progression, before gross tissue defects such as ruptures become visible," research scientist Alexej Jerschow, Ph.D., of the NYU School of Medicine, told 

 "Used preventively, it can also look at patients over time to see what treatments are effective."Jerschow reported the findings jointly with Ravinder R. Regatte, Ph.D., at the 2008 American Chemical Society meeting Aug. 20. Osteoarthritis results when the cartilage that cushions the bones of the joints begins to break down, causing pain and loss of mobility. GAG contains water that gives cartilage its resilience and elasticity. A low concentration of GAG is known to coincide with the onset of cartilage disorders.Enhanced MRI can be used to detect osteoarthritis, but it does not directly assess GAG levels, Jerschow said. The research team's chemical exchange-dependent saturation transfer method, or gagCEST, separates the protons and hydrogen content in GAG to produce a type of natural contrast agent, making it possible to monitor GAG and assess joint health in a clinical setting.Osteoarthritis afflicts almost 21 million patients in the U.S. - nearly half of them over the age of 65 - and is the leading cause of joint replacement. The disease is usually not diagnosed until it has advanced to the point at which replacement surgery may be the only treatment. Osteoarthritis accounts for about seven million primary physician visits per year and 50% of nonsteroidal anti-inflammatory drug usage. As the population ages, these numbers are expected to climb.Early diagnosis with the gagCEST MR approach could help prevent or reduce permanent joint damage, especially with evidence that dietary supplements like glucosamine and chondroitin can halt further joint degeneration, Jerschow said.The new imaging technique can be implemented on many MR scanners without hardware modifications and does not require significantly more time than a typical MR scan. Testing and diagnosis can be done on the same day."As we gain more insight into osteoarthritis with this and other methods, perhaps a full explanation of the mechanism and prevention of this disease can be found," Jerschow said. 

For more information from the Diagnostic Imaging archives: 

3T MRI improves diagnosis, management of knee osteoarthritis

3T MR articular cartilage maps prove their worth

Osteoarthritis may signal speedier biological aging

Articles

A novel MRI technique that tracks naturally occurring polymers in cartilage can lead to the diagnosis of early-stage osteoarthritis and may lead to better drug treatment and a reduction in the need for joint replacement surgeries.

MRI strategy supplies early warning of osteoarthritis

Massachusetts General Hospital researchers have added to the roll of preliminary evidence suggesting that 64-slice coronary CT angiography can serve as a useful adjunct for emergency department patients who present with acute chest pain.

Guided by senior researcher Dr. G. Scott Gazelle, director of the MGH Institute for Technology Assessment, researchers assessed the cost-effectiveness of 64-slice CTA on patients at low risk for acute coronary syndrome.

Results were published in August issue of the 

Based on the findings, principal investigator Joseph A. Ladapo suggested that coronary CTA could lead to shorter ED waits, potential cost benefits, and more accurate diagnoses for patients with possible heart attack or unstable angina. 

"Our study cautiously reinforces the potential for this technology to play a role in care," said Ladapo, a Harvard medical and public policy student, in an interview with 

The standard of care protocol calls for a patient with acute chest pain, negative initial biomarkers, a normal or nondiagnostic ECG, and no history of heart disease to undergo cardiac enzyme measurements. 

If troponin is normal, the patient is discharged. If it's elevated, the patient has a stress test. A negative stress test leads to discharge, while a positive result indicates the cath lab. With CTA, the patient is imaged and discharged with no further testing if the arteries are normal. Those with mild atherosclerosis or significant stenosis undergo the standard of care protocol. 

When CTA was used to triage 55-year-old men with acute chest pain, emergency room and hospital costs increased by $110 and total healthcare costs by $200. In 55-year-old women, ED and hospital costs decreased $410, and total healthcare costs decreased $380. 

Though CTA raised overall costs in men, it was more likely to identify patients with cornonary artery disease. As a result, the health risks for these patients were lowered. 

Compared with the standard of care, CTA-based triage extended life expectancy by 10 days in men and six days in women. 

A 2007 randomized controlled trial (Goldstein et al) assessed the health outcomes of CTA. The current study is the first to focus on the economics as well, Ladapo said. 

"The big risk with routine use of the exam is that it has historically exposed patients to pretty high doses of radiation, but physicians have developed protocols that reduce the radiation load significantly," he said. "My hunch is the exposure may be low enough now to routinely use the test to triage low to intermediate-risk patients who would otherwise end up receiving many more tests and spending much more time in the ED."

Researchers also accounted for several parameters, including the rate at which these patients returned to the emergency department, the test characteristics of CTA, and the cost of CTA.

"Nonetheless, 64-MDCT coronary angiography-based triage was generally still associated with improved health benefits in both sexes and cost savings in women when compared with the standard of care," they said.

For more information from the Diagnostic Imaging archives:

Coronary CT speed, resolution eduge out catheter angiography

CTA seeks niche triage role in unstable angina patients

Massive trial uses imaging to assess myocardial, stroke risk

Coronary CTA proves cost-effective for low-risk acute chest pain patients

    Copayments may make financial sense for insurers, but mammographers are appalled that some older women are avoiding routine screening because their Medicare managed-care plans force them to pony up for a portion of the imagingprocedure. 

    Dr. Amal Trivedi and colleagues at Brown University uncovered the pattern as they reviewed coverage for 174 Medicare managed-care plans and screening mammography utilization for those plans’ beneficiaries, more than 550,000 women aged 65 to 69. The study was published in the Jan. 24  New England Journal of Medicine  (2008:358[4]:375-383). 

    They found that the number of Medicare managed-care plans that required a copayment of at least $12.50 (range: $12.50 to $35) or coinsurance of more than 10% for screening mammography increased from three plans in 2001 to 21 plans in 2004. 

    And the percentage of women who took advantage of Medicare’s biennial coverage of screening mammography decreased. Among plans that required cost sharing, the biennial breast cancer screening rates were 8.3 percentage points lower than for Medicare managed-care plans that provided full coverage (77.5% for full coverage versus 69.2% for cost-shared plans). Biennial screening mammography increased 3.4% in the four-year study period for women who participated in the plans that did not require copayments or coinsurance. 

    The findings were troubling for Dr. Carol H. Lee, chair of the American College of Radiology’s breast imaging commission. 

    “We are taking a segment of the population in whom the test works best and adding a disincentive to getting it. Given limited healthcare resources and limited dollars, perhaps this is not the best place to save money,” she said. 

Copayments turn older women off to mammography

Women with Paget's disease of the nipple can be more assured that MRI will detect otherwise hidden malignancies, leading to opportunities for breast conserving therapy, following research from the Memorial Sloan-Kettering Cancer Center in New York City.

Paget's disease of the nipple is a rare type of carcinoma that presents clinically on the skin's surface. Symptoms can include an eczema-like scaling or rash, inflammation of the areola, fluid discharge, or inversion of the nipple. Diagnosis is confirmed by nipple biopsy, and about 95% of cases are associated with an underlying breast cancer.

The study involved surgically identified breast cancer in 32 of 34 (94%) Paget's disease patients evaluated at MSKCC from 1995 to 2006. Seven involved invasive ductal carcinoma, and 25 were ductal carcinoma in situ, with 19 of the cancers confined to the central quadrant of the breast.

Journal of the American College of Surgeons

Senior author Dr. Tari A. King and colleagues found that MRI effectively diagnosed carcinomas that mammography had missed. Diagnostic mammography performed on all 34 patients detected 11 cancers and accurately demonstrated the extent of disease in nine of 11 patients. MRI performed on 13 patients detected seven cancers and revealed the extent of disease in six of seven patients. In combination, mammography and MRI detected 15 (49%) of the malignancies.

MRI did not influence patient management when performed after positive mammography, but it proved valuable when initial diagnostic mammography was negative, King said. In such instances, MRI detected occult disease in four of eight patients. It was 100% sensitive in characterizing the extent of disease and ruled out the presence of cancer for one patient. In several instances, MRI findings allowed surgeons to perform lumpectomy rather than mastectomy, the standard treatment for women with Paget's disease.

"If the breast cancer is confined to the area behind the nipple, central lumpectomy with removal of the nipple areolar complex may be an attractive option for the patient. If this can be achieved with a negative margin, breast conservation (lumpectomy and whole-breast radiation therapy) may be performed," King said. 

Women with Paget’s disease of the nipple can be more assured that MRI will detect otherwise hidden malignancies, leading to opportunities for breast conserving therapy, following research from the Memorial Sloan-Kettering Cancer Center in New York City.

MRI detects occult breast cancer in Paget’s disease patients

Workforce projections from the U.S. Bureau of Labor Statistics suggest the supply of imaging and radiation oncology technologists may exceed demand by 2016, despite a flat school enrollment. A study by the American Society of Radiologic Technologists suggests that, if BLS forecasts are accurate, the industry could be producing almost double the number of radiation therapists, and almost triple the number of nuclear medicine technologists, than will be necessary in the next decade. "This is indeed a dramatic turnaround from just seven or eight years ago, when the overall vacancy rate for RTs was over 15% -- higher, on percentage basis, than for nurses," said ASRT director of research Richard Harris, Ph.D., in an interview with 

 "The profession has done a great job of bringing supply and demand into closer balance, but we can't continue at the current rate of recruitment and retention in the profession without risking an oversupply situation."Information for the 2007 ASRT Enrollment Snapshot, published in December 2007, was obtained from program directors at almost two-thirds of educational programs recognized by the American Registry of Radiologic Technologists. 

 An estimated 16,612 first-year students were enrolled last year in radiography programs (an increase of 1.2%).

 1577 were enrolled in radiation therapy programs (an increase of 3.3%).

 1781 were enrolled in nuclear medicine technology programs (a decrease of 1.3%).

 56,000 additional radiographers will be needed between 2006 and 2016 (20,000 fewer than BLS projections for the 2004-2014 period).

 6000 more radiation therapists will be needed in the same 10-year period (1000 fewer than estimated for 2004-2014).

 6000 more nuclear medicine technologists will be needed to meet increased demand and attrition through 2016 (1000 fewer than indicated in the previous projections).

Several important factors could mitigate the oversupply predictions, Harris said. Among them are innovations in nuclear and molecular imaging, which could lead to more demand for practitioners in the major disciplines, the aging of the baby boomer population, which should lead to greater demand for procedures in radiologic technology, and an expected wave of retirement among practitioners who began working in the 1970s.

The ASRT's 2007 therapy staffing survey also indicates a growing demand for other imaging professionals. Vacancy rates were 10.7% for medical dosimetrists, 10.4% for radiation oncologists, and 9% for medical physicists.Harris noted that the leveling off of enrollments suggests the profession is already responding to a potential glut. "Four percent to 5% of full-time-equivalent enrollments budgeted for radiographers, and a higher percentage of FTEs for other specialties within radiologic technology, are now going unfilled," he said.Reliable data will not be available until 2010, when the ASRT's first complete set of enrollment projections can be assessed. In the meantime, ASRT analysts believe the radiologic technology specialties continue to be attractive professional options. For more information from the Diagnostic Imaging archives:

ER-dedicated practitioners may address workload challenges

Mammography waiting times reach crisis level in southern states

Imaging technologists enjoy continuing income growth

Workforce projections from the U.S. Bureau of Labor Statistics suggest the supply of imaging and radiation oncology technologists may exceed demand by 2016, despite a flat school enrollment.

Labor bureau predicts end for chronic tech shortage

Experienced mammographers are concerned that managed care insurers increasingly require copayments and coinsurance fees for screening mammography. The trend is discouraging women from receiving the potentially life-saving imaging procedure.

Dr. Amal Trivedi and colleagues at Brown University uncovered the pattern as they reviewed coverage from 2001 to 2004 for 174 Medicare managed care plans and screening mammography utilization for their beneficiaries, more than 550,000 women aged 65 to 69. The study was published in the Jan. 24 

They found that the number of Medicare managed care plans that required a copayment of at least $12.50 (range: $12.50 to $35) or coinsurance of more than 10% for screening mammography rose steadily from year to year. Twenty-one plans enforced the requirements in 2004, up from three plans in 2001. 

For those plans, the biennial breast cancer screening rates at the end of the period were 8.3 percentage points lower than for Medicare managed care plans that provided full coverage (77.5% for full coverage versus 69.2% for cost-shared plans). Biennial screening mammography increased 3.4% in the four-year study period for women who participated in the plans that did not require copayments or coinsurance. 

The effect of cost sharing was magnified among women with incomes below the poverty line and for those who had not attended college. 

"It's dramatic to think that a relatively small copayment - $10, $20 - would cause women to choose not to get a mammogram," Dr. Peter B. Bach, an epidemiologist with the Health Outcomes Research Group at Memorial Sloan-Kettering Cancer Center, told 

 "They are opting out of the service, even though it's one of the best we have."

In an editorial accompanying the study, Bach observed that a central premise of high-deductible managed care plans - in which third-party insurers increase cost sharing to reduce unnecessary or ineffective procedures - is that patients will take more responsibility for their own health and will seek high-quality and efficient providers, because they will save money by doing so. Results from Trivedi's study challenge that assumption. 

"A knowledgeable consumer would opt for services that deliver value for a dollar. In the plans studied by Trivedi et al, mammography was a good value, with a meaningful gain in life expectancy available at a cost to patients of only $10 to $20 per mammogram," Bach said.

Oncology nurse Linnea Brown, breast health coordinator for the AtlantiCare Healthcare System in southern New Jersey, worries that breast cancer death rates could rise because copayments discourage poor and middle-class women from routine screening.

 "Mammograms don't prevent breast cancer, but they can find it much earlier, and early detection is the key," she said. "We could see mortality rates increase, even though the incidence of breast cancer has gone down."

Dr. Carol H. Lee, chair of the American College of Radiology's breast imaging commission, noted that breast cancer mortality has dropped about 25% among women who undergo routine screening and that the ability of mammograms to detect breast cancer increases with the patient's age. These and other factors suggest to Lee that copayments could ultimately cost the managed care insurers and Medicare more money than they save. 

"We are taking a segment of the population in whom the test works best and adding a disincentive to getting it. Given limited healthcare resources and limited dollars, perhaps this is not the best place to save money," she said.

Based on the study's results, Bach concluded the copayments encourage women to make poor healthcare decisions.

"There has been a pretty well-documented phenomenon that cost sharing decreases the utilization of services, so you don't do it with services you want people to have," Bach said. "That's the key metric, not to drive down premiums, but because it is an appropriate use of a healthcare resource."

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