Imaging

PHILADELPHIA – Individuals with asthma or chronic obstructive pulmonary disease can tolerate the imaging agent regadenoson well if they need to undergo cardiac stress testing, a study has shown.

Dr. Bruce Prenner, a San Diego allergist, reported on findings from a multicenter trial involving 999 patients who received either regadenoson or a placebo. “Regadenoson has a greater affinity for the A2B receptors and the other types of receptors, and thus the risk of bronchospasm and bronchoreactive events should be quite low,” he said at the meeting.

The risks of adenosine inducing breathing problems in individuals with asthma and COPD have been well documented. This study set out to determine how regadenoson affected forced expiratory volume in 1 second (FEV₁) in 999 study subjects, 532 with asthma and 467 with COPD. About half of the patients received the placebo. The primary end point was a greater than 15% decrease in forced expiratory function from baseline within 2 hours of the dose being administered, Dr. Prenner said.

“In the asthma group, 1.1% of [regadenoson] patients had an FEV₁ decrease greater than 15%, and 2.9% of patients on placebo,” had such a reduction, he said. Among patients with COPD, 4.2% receiving regadenoson and 5.4% on placebo met the primary end point, he said.

Respiratory problems such as wheezing, dyspnea, obstructive airwaves disorder and tachypnea were more common with regadenoson than placebo: 13% vs. 2%, respectively, in the asthma group; and 19% vs. 4% in the COPD patients. “The asthma patients had less frequency in terms of previous studies,” Dr. Prenner said. He said the variation between regadenoson and placebo was driven by dyspnea, a known side effect of A2A agonists.

However, within 1 day of injection, use of short-acting bronchodilators was similar for those who received both regadenoson and placebo, Dr. Prenner reported. In subjects with asthma, 1.4% of the regadenoson group and 1.1% of the placebo group used the inhalers. Among those with COPD, inhaler the rates were 1.6% and 1.3%, respectively, for the regadenoson and placebo cohorts.

The study showed no clinically meaningful differences between treatments in pulmonary function tests in either group, Dr. Prenner said. While the incidence of adverse events was higher with regadenoson, the adverse event profile was similar to that in previous regadenoson trials in nonasthmatic COPD patients. Of six serious adverse events with regadenoson, three were considered treatment related.

“This information should be very useful in considering the selection of regadenoson as a bottom-line stress agent for myocardial perfusion imaging in these types of patient populations,” Dr. Prenner said.

Dr. Prenner is a scientific adviser to Astellas, the manufacturer of regadenoson, and serves on its speakers bureau.

PHILADELPHIA – Individuals with asthma or chronic obstructive pulmonary disease can tolerate the imaging agent regadenoson well if they need to undergo cardiac stress testing, a study has shown.

Dr. Bruce Prenner, a San Diego allergist, reported on findings from a multicenter trial involving 999 patients who received either regadenoson or a placebo. “Regadenoson has a greater affinity for the A2B receptors and the other types of receptors, and thus the risk of bronchospasm and bronchoreactive events should be quite low,” he said at the meeting.

The risks of adenosine inducing breathing problems in individuals with asthma and COPD have been well documented. This study set out to determine how regadenoson affected forced expiratory volume in 1 second (FEV₁) in 999 study subjects, 532 with asthma and 467 with COPD. About half of the patients received the placebo. The primary end point was a greater than 15% decrease in forced expiratory function from baseline within 2 hours of the dose being administered, Dr. Prenner said.

“In the asthma group, 1.1% of [regadenoson] patients had an FEV₁ decrease greater than 15%, and 2.9% of patients on placebo,” had such a reduction, he said. Among patients with COPD, 4.2% receiving regadenoson and 5.4% on placebo met the primary end point, he said.

Respiratory problems such as wheezing, dyspnea, obstructive airwaves disorder and tachypnea were more common with regadenoson than placebo: 13% vs. 2%, respectively, in the asthma group; and 19% vs. 4% in the COPD patients. “The asthma patients had less frequency in terms of previous studies,” Dr. Prenner said. He said the variation between regadenoson and placebo was driven by dyspnea, a known side effect of A2A agonists.

However, within 1 day of injection, use of short-acting bronchodilators was similar for those who received both regadenoson and placebo, Dr. Prenner reported. In subjects with asthma, 1.4% of the regadenoson group and 1.1% of the placebo group used the inhalers. Among those with COPD, inhaler the rates were 1.6% and 1.3%, respectively, for the regadenoson and placebo cohorts.

The study showed no clinically meaningful differences between treatments in pulmonary function tests in either group, Dr. Prenner said. While the incidence of adverse events was higher with regadenoson, the adverse event profile was similar to that in previous regadenoson trials in nonasthmatic COPD patients. Of six serious adverse events with regadenoson, three were considered treatment related.

“This information should be very useful in considering the selection of regadenoson as a bottom-line stress agent for myocardial perfusion imaging in these types of patient populations,” Dr. Prenner said.

Dr. Prenner is a scientific adviser to Astellas, the manufacturer of regadenoson, and serves on its speakers bureau.

PHILADELPHIA – Individuals with asthma or chronic obstructive pulmonary disease can tolerate the imaging agent regadenoson well if they need to undergo cardiac stress testing, a study has shown.

Dr. Bruce Prenner, a San Diego allergist, reported on findings from a multicenter trial involving 999 patients who received either regadenoson or a placebo. “Regadenoson has a greater affinity for the A2B receptors and the other types of receptors, and thus the risk of bronchospasm and bronchoreactive events should be quite low,” he said at the meeting.

The risks of adenosine inducing breathing problems in individuals with asthma and COPD have been well documented. This study set out to determine how regadenoson affected forced expiratory volume in 1 second (FEV₁) in 999 study subjects, 532 with asthma and 467 with COPD. About half of the patients received the placebo. The primary end point was a greater than 15% decrease in forced expiratory function from baseline within 2 hours of the dose being administered, Dr. Prenner said.

“In the asthma group, 1.1% of [regadenoson] patients had an FEV₁ decrease greater than 15%, and 2.9% of patients on placebo,” had such a reduction, he said. Among patients with COPD, 4.2% receiving regadenoson and 5.4% on placebo met the primary end point, he said.

Respiratory problems such as wheezing, dyspnea, obstructive airwaves disorder and tachypnea were more common with regadenoson than placebo: 13% vs. 2%, respectively, in the asthma group; and 19% vs. 4% in the COPD patients. “The asthma patients had less frequency in terms of previous studies,” Dr. Prenner said. He said the variation between regadenoson and placebo was driven by dyspnea, a known side effect of A2A agonists.

However, within 1 day of injection, use of short-acting bronchodilators was similar for those who received both regadenoson and placebo, Dr. Prenner reported. In subjects with asthma, 1.4% of the regadenoson group and 1.1% of the placebo group used the inhalers. Among those with COPD, inhaler the rates were 1.6% and 1.3%, respectively, for the regadenoson and placebo cohorts.

The study showed no clinically meaningful differences between treatments in pulmonary function tests in either group, Dr. Prenner said. While the incidence of adverse events was higher with regadenoson, the adverse event profile was similar to that in previous regadenoson trials in nonasthmatic COPD patients. Of six serious adverse events with regadenoson, three were considered treatment related.

“This information should be very useful in considering the selection of regadenoson as a bottom-line stress agent for myocardial perfusion imaging in these types of patient populations,” Dr. Prenner said.

Dr. Prenner is a scientific adviser to Astellas, the manufacturer of regadenoson, and serves on its speakers bureau.

PHILADELPHIA – Population exposure to medical radiation increased by 700% between 1980 and 2006, and nuclear cardiologists are feeling the pressure to reduce patients' radiation exposure, according to Dr. Milena J. Henzlova of Mt. Sinai School of Medicine in New York.

“This is the first time in history that exposure to medical radiation exceeds natural radiation in the population,” she reported at the meeting.

Reasons for this increased radiation exposure are varied and range from the availability of improved technology and deteriorating health of the general population, to the economic interests of manufacturers and providers, Dr. Henzlova said. In addition, “more noncardiologists are also referring [patients] for diagnostic studies, which is unusual in other medical subspecialties”

Dr. Henzlova outlined ways in which nuclear cardiologists could reduce radiation dosing in their patient populations.

One method is to follow existing American Society of Nuclear Cardiology guidelines and appropriateness criteria and the ALARA – as low as reasonably achievable – principle, she advised.

She also encouraged physicians to focus dose reduction on younger patients, though “if the patient is in the ninth decade of life, maybe this principle becomes irrelevant.”

More broadly, more regulation of the imaging equipment might help rein in the dosing. Furthermore, physicians and patients should become better educated in the hazards of medical radiation and the benefits of dose reduction, she said.

Dose-reduction methods nuclear cardiologists can use immediately include what she called “stress-first testing” rather than full stress-rest testing.

“At least 50% of our stress-rest studies are normal, and when we looked at huge sets of data, we found that 60%–70% were normal,” Dr. Henzlova said. “If there is a reason for the rest imaging, it's to find the reversibility of a defect; but in more than half of patients there is no defect to start with.”

Her group studied results of more than 10,000 stress-rest tests and found that outcomes over 5 years were almost identical between the stress-only and image study groups. “We concluded that a normal stress study has the same 1-year prognosis as a full stress-rest study,” she said. “This is an attractive alternative to the stress-rest study in appropriately selected patients. Ultimately, time is saved, radiation is saved, and cost is decreased.”

Nuclear cardiologists could also opt for a 2-day rest study with lower doses of radiation, she said, referring to U.S. and European protocols. In a cohort at the Mt. Sinai School of Medicine, total microcuries (mCi) ranged from 48 to 72, compared with 33.8 to 47.3 in a European report on 2-day studies.

Dr. Benjamin Chow, of the University of Ottawa Heart Institute in Canada, also reported on dose reduction methods for cardiac CT. The methods he described included minimizing tube current (the number of electrons used) and tube voltage (the energy level of the electrons).

“The bottom line is that if you maintain adequate signal dose and adequate initial quality with lower tube current, in general that lowers radiation exposure,” he said.

The dose-reduction methods Dr. Chow reviewed included maintaining the tube current as the CT projects across the chest but reducing it across smaller body areas, turning off the scanner when the patient changes position, using bowtie filters, and activating the padding function, which can also reduce costs by up to 82%. He cautioned, however, that there would be some loss of image quality with padding.

Tube modulation is another method of maximizing imaging during the patient's diastasis and minimizing it during systole, he said, but this also has its drawbacks, because although it restricts the amount of time the patient is exposed to radiation, “you may lose the ability to read different phases of the study.”

Dr. Chow said that his center routinely uses breast shields for women undergoing cardiac CT, which have been shown to reduce radiation exposure to the breast and lung, by 30% and 15%, respectively.

Neither Dr. Henzlova nor Chow had any relevant disclosures.

Vitals

PHILADELPHIA – Population exposure to medical radiation increased by 700% between 1980 and 2006, and nuclear cardiologists are feeling the pressure to reduce patients' radiation exposure, according to Dr. Milena J. Henzlova of Mt. Sinai School of Medicine in New York.

“This is the first time in history that exposure to medical radiation exceeds natural radiation in the population,” she reported at the meeting.

Reasons for this increased radiation exposure are varied and range from the availability of improved technology and deteriorating health of the general population, to the economic interests of manufacturers and providers, Dr. Henzlova said. In addition, “more noncardiologists are also referring [patients] for diagnostic studies, which is unusual in other medical subspecialties”

Dr. Henzlova outlined ways in which nuclear cardiologists could reduce radiation dosing in their patient populations.

One method is to follow existing American Society of Nuclear Cardiology guidelines and appropriateness criteria and the ALARA – as low as reasonably achievable – principle, she advised.

She also encouraged physicians to focus dose reduction on younger patients, though “if the patient is in the ninth decade of life, maybe this principle becomes irrelevant.”

More broadly, more regulation of the imaging equipment might help rein in the dosing. Furthermore, physicians and patients should become better educated in the hazards of medical radiation and the benefits of dose reduction, she said.

Dose-reduction methods nuclear cardiologists can use immediately include what she called “stress-first testing” rather than full stress-rest testing.

“At least 50% of our stress-rest studies are normal, and when we looked at huge sets of data, we found that 60%–70% were normal,” Dr. Henzlova said. “If there is a reason for the rest imaging, it's to find the reversibility of a defect; but in more than half of patients there is no defect to start with.”

Her group studied results of more than 10,000 stress-rest tests and found that outcomes over 5 years were almost identical between the stress-only and image study groups. “We concluded that a normal stress study has the same 1-year prognosis as a full stress-rest study,” she said. “This is an attractive alternative to the stress-rest study in appropriately selected patients. Ultimately, time is saved, radiation is saved, and cost is decreased.”

Nuclear cardiologists could also opt for a 2-day rest study with lower doses of radiation, she said, referring to U.S. and European protocols. In a cohort at the Mt. Sinai School of Medicine, total microcuries (mCi) ranged from 48 to 72, compared with 33.8 to 47.3 in a European report on 2-day studies.

Dr. Benjamin Chow, of the University of Ottawa Heart Institute in Canada, also reported on dose reduction methods for cardiac CT. The methods he described included minimizing tube current (the number of electrons used) and tube voltage (the energy level of the electrons).

“The bottom line is that if you maintain adequate signal dose and adequate initial quality with lower tube current, in general that lowers radiation exposure,” he said.

The dose-reduction methods Dr. Chow reviewed included maintaining the tube current as the CT projects across the chest but reducing it across smaller body areas, turning off the scanner when the patient changes position, using bowtie filters, and activating the padding function, which can also reduce costs by up to 82%. He cautioned, however, that there would be some loss of image quality with padding.

Tube modulation is another method of maximizing imaging during the patient's diastasis and minimizing it during systole, he said, but this also has its drawbacks, because although it restricts the amount of time the patient is exposed to radiation, “you may lose the ability to read different phases of the study.”

Dr. Chow said that his center routinely uses breast shields for women undergoing cardiac CT, which have been shown to reduce radiation exposure to the breast and lung, by 30% and 15%, respectively.

Neither Dr. Henzlova nor Chow had any relevant disclosures.

Vitals

PHILADELPHIA – Population exposure to medical radiation increased by 700% between 1980 and 2006, and nuclear cardiologists are feeling the pressure to reduce patients' radiation exposure, according to Dr. Milena J. Henzlova of Mt. Sinai School of Medicine in New York.

“This is the first time in history that exposure to medical radiation exceeds natural radiation in the population,” she reported at the meeting.

Reasons for this increased radiation exposure are varied and range from the availability of improved technology and deteriorating health of the general population, to the economic interests of manufacturers and providers, Dr. Henzlova said. In addition, “more noncardiologists are also referring [patients] for diagnostic studies, which is unusual in other medical subspecialties”

Dr. Henzlova outlined ways in which nuclear cardiologists could reduce radiation dosing in their patient populations.

One method is to follow existing American Society of Nuclear Cardiology guidelines and appropriateness criteria and the ALARA – as low as reasonably achievable – principle, she advised.

She also encouraged physicians to focus dose reduction on younger patients, though “if the patient is in the ninth decade of life, maybe this principle becomes irrelevant.”

More broadly, more regulation of the imaging equipment might help rein in the dosing. Furthermore, physicians and patients should become better educated in the hazards of medical radiation and the benefits of dose reduction, she said.

Dose-reduction methods nuclear cardiologists can use immediately include what she called “stress-first testing” rather than full stress-rest testing.

“At least 50% of our stress-rest studies are normal, and when we looked at huge sets of data, we found that 60%–70% were normal,” Dr. Henzlova said. “If there is a reason for the rest imaging, it's to find the reversibility of a defect; but in more than half of patients there is no defect to start with.”

Her group studied results of more than 10,000 stress-rest tests and found that outcomes over 5 years were almost identical between the stress-only and image study groups. “We concluded that a normal stress study has the same 1-year prognosis as a full stress-rest study,” she said. “This is an attractive alternative to the stress-rest study in appropriately selected patients. Ultimately, time is saved, radiation is saved, and cost is decreased.”

Nuclear cardiologists could also opt for a 2-day rest study with lower doses of radiation, she said, referring to U.S. and European protocols. In a cohort at the Mt. Sinai School of Medicine, total microcuries (mCi) ranged from 48 to 72, compared with 33.8 to 47.3 in a European report on 2-day studies.

Dr. Benjamin Chow, of the University of Ottawa Heart Institute in Canada, also reported on dose reduction methods for cardiac CT. The methods he described included minimizing tube current (the number of electrons used) and tube voltage (the energy level of the electrons).

“The bottom line is that if you maintain adequate signal dose and adequate initial quality with lower tube current, in general that lowers radiation exposure,” he said.

The dose-reduction methods Dr. Chow reviewed included maintaining the tube current as the CT projects across the chest but reducing it across smaller body areas, turning off the scanner when the patient changes position, using bowtie filters, and activating the padding function, which can also reduce costs by up to 82%. He cautioned, however, that there would be some loss of image quality with padding.

Tube modulation is another method of maximizing imaging during the patient's diastasis and minimizing it during systole, he said, but this also has its drawbacks, because although it restricts the amount of time the patient is exposed to radiation, “you may lose the ability to read different phases of the study.”

Dr. Chow said that his center routinely uses breast shields for women undergoing cardiac CT, which have been shown to reduce radiation exposure to the breast and lung, by 30% and 15%, respectively.

Neither Dr. Henzlova nor Chow had any relevant disclosures.

Vitals

PHILADELPHIA – A protocol for using serial gated single-photon emission computed tomography with a single injection radiotracer helped in patient selection for cardiac resynchronization therapy and guided left ventricle lead placement, investigators at the University of Pittsburgh reported.

The phased analysis protocol involved leaving the cardiac resynchronization therapy (CRT) device inactive at the time of implantation, injecting a single dose of radiotracer, and acquiring a resting gated single-photon emission computed tomography (SPECT); then activating the CRT and acquiring another gated SPECT, said Dr. Mati Friehling. The study was selected as winner of the ASNC's Young Investigator Award Competition.

“There is great value of phase analysis which suggests a new technique to evaluate LV synchrony,” Dr. Friehling said. “There's a linear relationship between the count changes throughout the cardiac cycle and myocardial wall thickening.”

The count changes are key to determining the precise mechanical contraction for CRT, he said.

“One question is, why do we care about the acute response?” Dr. Friehling said. “When we put a CRT device in, based on conventional criteria, we assume that acute resynchronization occurs, and this will give us a long-term benefit, but not always.

“We decided to use a gated SPECT-based approach because it gives us a congregant evaluation of the patient, including function and scar location and scar extent, which may be helpful for actual LV lead position.”

The single-dose radiotracer was devised to limit radiation exposure, he said.

The study analyzed a total of 44 patients after CRT device implantation, 18 of whom had improvement of dyssynchrony, 11 of whom had no change, and 15 of whom actually had deterioration of dyssynchrony, Dr. Friehling said.

The leads were concordant in 22 patients, only 1 of whom actually worsened. In the remaining 22 with discordant leads, 8 had improvement or were unchanged, and 14 saw their dyssynchrony worsen, according to Dr. Friehling.

“There's a very high specificity and positive predictive value for an improving or unchanged synchrony,” said Dr. Friehling.

“The responses are based on small changes in LV volume injection fraction according to echocardiography, which can be highly variable. We used harder end points such as death, CHF hospitalizations, ICD shocks, and viability of patients secondary to HF failure symptoms,” he noted.

Five deaths were reported among the 29 patients in the study group who had improved or unchanged dyssynchrony, Dr. Friehling said, while among the 15 patients who had deterioration of dyssynchrony, 8 had a cardiac event.

“Serial imaging based on conventional criteria can result in acute worsening of synchrony in some patients,” Dr. Friehling said.

“The acute change in synchrony does appear to be associated with long-term outcome, and we may be able to use a baseline SPECT study to guide LV lead placement and to predict the acute response. Therefore SPECT may be a valuable tool for selecting patients for CRT.”

Dr. Friehling had no disclosures, but two of his coinvestigators disclosed relationships with Emory Cardiac Toolbox.

PHILADELPHIA – A protocol for using serial gated single-photon emission computed tomography with a single injection radiotracer helped in patient selection for cardiac resynchronization therapy and guided left ventricle lead placement, investigators at the University of Pittsburgh reported.

The phased analysis protocol involved leaving the cardiac resynchronization therapy (CRT) device inactive at the time of implantation, injecting a single dose of radiotracer, and acquiring a resting gated single-photon emission computed tomography (SPECT); then activating the CRT and acquiring another gated SPECT, said Dr. Mati Friehling. The study was selected as winner of the ASNC's Young Investigator Award Competition.

“There is great value of phase analysis which suggests a new technique to evaluate LV synchrony,” Dr. Friehling said. “There's a linear relationship between the count changes throughout the cardiac cycle and myocardial wall thickening.”

The count changes are key to determining the precise mechanical contraction for CRT, he said.

“One question is, why do we care about the acute response?” Dr. Friehling said. “When we put a CRT device in, based on conventional criteria, we assume that acute resynchronization occurs, and this will give us a long-term benefit, but not always.

“We decided to use a gated SPECT-based approach because it gives us a congregant evaluation of the patient, including function and scar location and scar extent, which may be helpful for actual LV lead position.”

The single-dose radiotracer was devised to limit radiation exposure, he said.

The study analyzed a total of 44 patients after CRT device implantation, 18 of whom had improvement of dyssynchrony, 11 of whom had no change, and 15 of whom actually had deterioration of dyssynchrony, Dr. Friehling said.

The leads were concordant in 22 patients, only 1 of whom actually worsened. In the remaining 22 with discordant leads, 8 had improvement or were unchanged, and 14 saw their dyssynchrony worsen, according to Dr. Friehling.

“There's a very high specificity and positive predictive value for an improving or unchanged synchrony,” said Dr. Friehling.

“The responses are based on small changes in LV volume injection fraction according to echocardiography, which can be highly variable. We used harder end points such as death, CHF hospitalizations, ICD shocks, and viability of patients secondary to HF failure symptoms,” he noted.

Five deaths were reported among the 29 patients in the study group who had improved or unchanged dyssynchrony, Dr. Friehling said, while among the 15 patients who had deterioration of dyssynchrony, 8 had a cardiac event.

“Serial imaging based on conventional criteria can result in acute worsening of synchrony in some patients,” Dr. Friehling said.

“The acute change in synchrony does appear to be associated with long-term outcome, and we may be able to use a baseline SPECT study to guide LV lead placement and to predict the acute response. Therefore SPECT may be a valuable tool for selecting patients for CRT.”

Dr. Friehling had no disclosures, but two of his coinvestigators disclosed relationships with Emory Cardiac Toolbox.

PHILADELPHIA – A protocol for using serial gated single-photon emission computed tomography with a single injection radiotracer helped in patient selection for cardiac resynchronization therapy and guided left ventricle lead placement, investigators at the University of Pittsburgh reported.

The phased analysis protocol involved leaving the cardiac resynchronization therapy (CRT) device inactive at the time of implantation, injecting a single dose of radiotracer, and acquiring a resting gated single-photon emission computed tomography (SPECT); then activating the CRT and acquiring another gated SPECT, said Dr. Mati Friehling. The study was selected as winner of the ASNC's Young Investigator Award Competition.

“There is great value of phase analysis which suggests a new technique to evaluate LV synchrony,” Dr. Friehling said. “There's a linear relationship between the count changes throughout the cardiac cycle and myocardial wall thickening.”

The count changes are key to determining the precise mechanical contraction for CRT, he said.

“One question is, why do we care about the acute response?” Dr. Friehling said. “When we put a CRT device in, based on conventional criteria, we assume that acute resynchronization occurs, and this will give us a long-term benefit, but not always.

“We decided to use a gated SPECT-based approach because it gives us a congregant evaluation of the patient, including function and scar location and scar extent, which may be helpful for actual LV lead position.”

The single-dose radiotracer was devised to limit radiation exposure, he said.

The study analyzed a total of 44 patients after CRT device implantation, 18 of whom had improvement of dyssynchrony, 11 of whom had no change, and 15 of whom actually had deterioration of dyssynchrony, Dr. Friehling said.

The leads were concordant in 22 patients, only 1 of whom actually worsened. In the remaining 22 with discordant leads, 8 had improvement or were unchanged, and 14 saw their dyssynchrony worsen, according to Dr. Friehling.

“There's a very high specificity and positive predictive value for an improving or unchanged synchrony,” said Dr. Friehling.

“The responses are based on small changes in LV volume injection fraction according to echocardiography, which can be highly variable. We used harder end points such as death, CHF hospitalizations, ICD shocks, and viability of patients secondary to HF failure symptoms,” he noted.

Five deaths were reported among the 29 patients in the study group who had improved or unchanged dyssynchrony, Dr. Friehling said, while among the 15 patients who had deterioration of dyssynchrony, 8 had a cardiac event.

“Serial imaging based on conventional criteria can result in acute worsening of synchrony in some patients,” Dr. Friehling said.

“The acute change in synchrony does appear to be associated with long-term outcome, and we may be able to use a baseline SPECT study to guide LV lead placement and to predict the acute response. Therefore SPECT may be a valuable tool for selecting patients for CRT.”

Dr. Friehling had no disclosures, but two of his coinvestigators disclosed relationships with Emory Cardiac Toolbox.

BRUSSELS – The use of magnetic resonance imaging may enable earlier recognition of knee osteoarthritis, and should be incorporated into recommended diagnostic criteria, a panel of 16 osteoarthritis experts concluded.

Using MRI to define knee osteoarthritis (OA) may allow detection of the disease before radiographic changes occur. But despite a growing body of literature on the role of MRI in OA, little uniformity exists for its diagnostic application, perhaps because of the absence of criteria for an MRI-based structural diagnosis of OA, the group said.

The Osteoarthritis Research Society International (OARSI) organized the 16-member panel, the OA Imaging Working Group, to develop an MRI-based definition of structural OA. The working group sought to identify structural changes on MRI that defined a structural diagnosis of knee OA, Dr. David J. Hunter and the other members of the working group wrote in a poster presented at the World Congress on Osteoarthritis, which was organized by OARSI.

The working group began with a literature review through April 2009, a process that yielded 25 studies that met the group’s inclusion criteria and evaluated MRI diagnostic performance. The 16 members also contributed candidate propositions dealing with key aspects of MRI diagnosis of knee OA.

Through a multiphase process of discussion and voting, the group agreed on the following set of nine propositions based on MRI criteria of knee OA:

1. MRI changes of OA may occur in the absence of radiographic findings of OA.

2. MRI may add to the diagnosis of OA and should be incorporated into the ACR diagnostic criteria including x-ray, clinical, and laboratory parameters.

3. MRI may be used for inclusion in clinical studies according to the criteria detailed above, but should not be a primary diagnostic tool in a clinical setting.

4. Certain MRI changes that occur in isolation are not diagnostic of OA. These include cartilage loss, change in cartilage composition, cystic change and development of bone marrow lesions, ligamentous and tendinous damage, meniscal damage, and effusion and synovitis.

5. No single finding is diagnostic of knee OA.

6. MRI findings indicative of knee OA may include abnormalities in all tissues of the joint (bone, cartilage, meniscus, synovium, ligament, and capsule).

7. Given the multiple tissue abnormalities detected by MRI in OA, diagnostic criteria are likely to involve several possible combinations of features.

8. Definite osteophyte production is indicative of OA.

9. Joint space narrowing as assessed by (nonweight bearing) MRI cannot be used as a diagnostic criterion.

Similarly, the working group agreed on the following two definitions for MRI findings that were diagnostic of knee OA:

1. Tibiofemoral OA should have either both features from group A (below), or one feature from group A and at least two features from group B. Examination of the patient must also rule out joint trauma within the last 6 months (by history) as well as inflammatory arthritis (diagnosed by radiographs, history, and laboratory findings).

• Group A features: Definite osteophyte formation; full thickness cartilage loss.

• Group B features: Subchondral bone marrow lesion or cyst not associated with meniscal or ligamentous attachments; meniscal subluxation, maceration, or degenerative (horizontal) tear; partial-thickness cartilage loss (without full thickness loss).

2. Patellofemoral OA requires both of the following features involving the patella or the anterior femur or both:

• Definite osteophyte formation.

• Partial- or full-thickness cartilage loss.

These constitute “statements of preamble and context setting.” The two definitions “offer an opportunity for formal testing against other diagnostic constructs,” said Dr. Hunter, a rheumatologist and professor of medicine at the University of Sydney and his associates in the working group.

The working group noted that the American College of Rheumatology in 1986 first released the current standard criteria for diagnosing OA, which deal only with radiographic imaging (Arthritis Rheum. 1986;29:1039-49). The European League Against Rheumatism published more current recommendations this year, but focused on a clinical diagnosis that did not involve imaging (Ann. Rheum. Dis. 2010;69:483-9).

The working group aimed to “include MRI as a means to define the disease with the intent that one may be able to identify early, pre-radiographic disease, thus enabling recruitment of study populations where structure modification (or structure maintenance) may be realistic in a more preventive manner.”

The group cautioned that prior to using the definitions, “it is important that their validity and diagnostic performance be adequately tested.” They also stressed that “the propositions have been developed for structural OA, not for a clinical diagnosis, not for early OA, and not to facilitate staging of the disease.” The propositions “are not to detract from, nor to discourage the use of traditional means for diagnosing OA.”

An osteoarthritis specialist who was not involved with the working group cautioned that waiting for MRI structural changes that are specific for OA may still miss a truly early diagnosis, before irreversible pathology occurred.

“It’s too early to know the definition of OA on MRI. We know what features of OA are on MRI, but that doesn’t mean we can make a diagnosis based on MRI,” commented Dr. Tuhina Neogi, a rheumatologist at Boston University. “There are early changes [seen with MRI] that are not picked up on radiographs, but we don’t yet have a standardized, validated definition of an earlier stage” on MRI, Dr. Neogi said in an interview.

Dr. Hunter said that he has received research support from AstraZeneca, DJO Inc. (DonJoy), Eli Lilly & Co., Merck & Co., Pfizer Inc., Stryker Corp., and Wyeth. Eight of the other members of the working group also provided disclosures, whereas the remaining seven members said they had no disclosures. Dr. Neogi had no disclosures.

BRUSSELS – The use of magnetic resonance imaging may enable earlier recognition of knee osteoarthritis, and should be incorporated into recommended diagnostic criteria, a panel of 16 osteoarthritis experts concluded.

Using MRI to define knee osteoarthritis (OA) may allow detection of the disease before radiographic changes occur. But despite a growing body of literature on the role of MRI in OA, little uniformity exists for its diagnostic application, perhaps because of the absence of criteria for an MRI-based structural diagnosis of OA, the group said.

The Osteoarthritis Research Society International (OARSI) organized the 16-member panel, the OA Imaging Working Group, to develop an MRI-based definition of structural OA. The working group sought to identify structural changes on MRI that defined a structural diagnosis of knee OA, Dr. David J. Hunter and the other members of the working group wrote in a poster presented at the World Congress on Osteoarthritis, which was organized by OARSI.

The working group began with a literature review through April 2009, a process that yielded 25 studies that met the group’s inclusion criteria and evaluated MRI diagnostic performance. The 16 members also contributed candidate propositions dealing with key aspects of MRI diagnosis of knee OA.

Through a multiphase process of discussion and voting, the group agreed on the following set of nine propositions based on MRI criteria of knee OA:

1. MRI changes of OA may occur in the absence of radiographic findings of OA.

2. MRI may add to the diagnosis of OA and should be incorporated into the ACR diagnostic criteria including x-ray, clinical, and laboratory parameters.

3. MRI may be used for inclusion in clinical studies according to the criteria detailed above, but should not be a primary diagnostic tool in a clinical setting.

4. Certain MRI changes that occur in isolation are not diagnostic of OA. These include cartilage loss, change in cartilage composition, cystic change and development of bone marrow lesions, ligamentous and tendinous damage, meniscal damage, and effusion and synovitis.

5. No single finding is diagnostic of knee OA.

6. MRI findings indicative of knee OA may include abnormalities in all tissues of the joint (bone, cartilage, meniscus, synovium, ligament, and capsule).

7. Given the multiple tissue abnormalities detected by MRI in OA, diagnostic criteria are likely to involve several possible combinations of features.

8. Definite osteophyte production is indicative of OA.

9. Joint space narrowing as assessed by (nonweight bearing) MRI cannot be used as a diagnostic criterion.

Similarly, the working group agreed on the following two definitions for MRI findings that were diagnostic of knee OA:

1. Tibiofemoral OA should have either both features from group A (below), or one feature from group A and at least two features from group B. Examination of the patient must also rule out joint trauma within the last 6 months (by history) as well as inflammatory arthritis (diagnosed by radiographs, history, and laboratory findings).

• Group A features: Definite osteophyte formation; full thickness cartilage loss.

• Group B features: Subchondral bone marrow lesion or cyst not associated with meniscal or ligamentous attachments; meniscal subluxation, maceration, or degenerative (horizontal) tear; partial-thickness cartilage loss (without full thickness loss).

2. Patellofemoral OA requires both of the following features involving the patella or the anterior femur or both:

• Definite osteophyte formation.

• Partial- or full-thickness cartilage loss.

These constitute “statements of preamble and context setting.” The two definitions “offer an opportunity for formal testing against other diagnostic constructs,” said Dr. Hunter, a rheumatologist and professor of medicine at the University of Sydney and his associates in the working group.

The working group noted that the American College of Rheumatology in 1986 first released the current standard criteria for diagnosing OA, which deal only with radiographic imaging (Arthritis Rheum. 1986;29:1039-49). The European League Against Rheumatism published more current recommendations this year, but focused on a clinical diagnosis that did not involve imaging (Ann. Rheum. Dis. 2010;69:483-9).

The working group aimed to “include MRI as a means to define the disease with the intent that one may be able to identify early, pre-radiographic disease, thus enabling recruitment of study populations where structure modification (or structure maintenance) may be realistic in a more preventive manner.”

The group cautioned that prior to using the definitions, “it is important that their validity and diagnostic performance be adequately tested.” They also stressed that “the propositions have been developed for structural OA, not for a clinical diagnosis, not for early OA, and not to facilitate staging of the disease.” The propositions “are not to detract from, nor to discourage the use of traditional means for diagnosing OA.”

An osteoarthritis specialist who was not involved with the working group cautioned that waiting for MRI structural changes that are specific for OA may still miss a truly early diagnosis, before irreversible pathology occurred.

“It’s too early to know the definition of OA on MRI. We know what features of OA are on MRI, but that doesn’t mean we can make a diagnosis based on MRI,” commented Dr. Tuhina Neogi, a rheumatologist at Boston University. “There are early changes [seen with MRI] that are not picked up on radiographs, but we don’t yet have a standardized, validated definition of an earlier stage” on MRI, Dr. Neogi said in an interview.

Dr. Hunter said that he has received research support from AstraZeneca, DJO Inc. (DonJoy), Eli Lilly & Co., Merck & Co., Pfizer Inc., Stryker Corp., and Wyeth. Eight of the other members of the working group also provided disclosures, whereas the remaining seven members said they had no disclosures. Dr. Neogi had no disclosures.

BRUSSELS – The use of magnetic resonance imaging may enable earlier recognition of knee osteoarthritis, and should be incorporated into recommended diagnostic criteria, a panel of 16 osteoarthritis experts concluded.

Using MRI to define knee osteoarthritis (OA) may allow detection of the disease before radiographic changes occur. But despite a growing body of literature on the role of MRI in OA, little uniformity exists for its diagnostic application, perhaps because of the absence of criteria for an MRI-based structural diagnosis of OA, the group said.

The Osteoarthritis Research Society International (OARSI) organized the 16-member panel, the OA Imaging Working Group, to develop an MRI-based definition of structural OA. The working group sought to identify structural changes on MRI that defined a structural diagnosis of knee OA, Dr. David J. Hunter and the other members of the working group wrote in a poster presented at the World Congress on Osteoarthritis, which was organized by OARSI.

The working group began with a literature review through April 2009, a process that yielded 25 studies that met the group’s inclusion criteria and evaluated MRI diagnostic performance. The 16 members also contributed candidate propositions dealing with key aspects of MRI diagnosis of knee OA.

Through a multiphase process of discussion and voting, the group agreed on the following set of nine propositions based on MRI criteria of knee OA:

1. MRI changes of OA may occur in the absence of radiographic findings of OA.

2. MRI may add to the diagnosis of OA and should be incorporated into the ACR diagnostic criteria including x-ray, clinical, and laboratory parameters.

3. MRI may be used for inclusion in clinical studies according to the criteria detailed above, but should not be a primary diagnostic tool in a clinical setting.

4. Certain MRI changes that occur in isolation are not diagnostic of OA. These include cartilage loss, change in cartilage composition, cystic change and development of bone marrow lesions, ligamentous and tendinous damage, meniscal damage, and effusion and synovitis.

5. No single finding is diagnostic of knee OA.

6. MRI findings indicative of knee OA may include abnormalities in all tissues of the joint (bone, cartilage, meniscus, synovium, ligament, and capsule).

7. Given the multiple tissue abnormalities detected by MRI in OA, diagnostic criteria are likely to involve several possible combinations of features.

8. Definite osteophyte production is indicative of OA.

9. Joint space narrowing as assessed by (nonweight bearing) MRI cannot be used as a diagnostic criterion.

Similarly, the working group agreed on the following two definitions for MRI findings that were diagnostic of knee OA:

1. Tibiofemoral OA should have either both features from group A (below), or one feature from group A and at least two features from group B. Examination of the patient must also rule out joint trauma within the last 6 months (by history) as well as inflammatory arthritis (diagnosed by radiographs, history, and laboratory findings).

• Group A features: Definite osteophyte formation; full thickness cartilage loss.

• Group B features: Subchondral bone marrow lesion or cyst not associated with meniscal or ligamentous attachments; meniscal subluxation, maceration, or degenerative (horizontal) tear; partial-thickness cartilage loss (without full thickness loss).

2. Patellofemoral OA requires both of the following features involving the patella or the anterior femur or both:

• Definite osteophyte formation.

• Partial- or full-thickness cartilage loss.

These constitute “statements of preamble and context setting.” The two definitions “offer an opportunity for formal testing against other diagnostic constructs,” said Dr. Hunter, a rheumatologist and professor of medicine at the University of Sydney and his associates in the working group.

The working group noted that the American College of Rheumatology in 1986 first released the current standard criteria for diagnosing OA, which deal only with radiographic imaging (Arthritis Rheum. 1986;29:1039-49). The European League Against Rheumatism published more current recommendations this year, but focused on a clinical diagnosis that did not involve imaging (Ann. Rheum. Dis. 2010;69:483-9).

The working group aimed to “include MRI as a means to define the disease with the intent that one may be able to identify early, pre-radiographic disease, thus enabling recruitment of study populations where structure modification (or structure maintenance) may be realistic in a more preventive manner.”

The group cautioned that prior to using the definitions, “it is important that their validity and diagnostic performance be adequately tested.” They also stressed that “the propositions have been developed for structural OA, not for a clinical diagnosis, not for early OA, and not to facilitate staging of the disease.” The propositions “are not to detract from, nor to discourage the use of traditional means for diagnosing OA.”

An osteoarthritis specialist who was not involved with the working group cautioned that waiting for MRI structural changes that are specific for OA may still miss a truly early diagnosis, before irreversible pathology occurred.

“It’s too early to know the definition of OA on MRI. We know what features of OA are on MRI, but that doesn’t mean we can make a diagnosis based on MRI,” commented Dr. Tuhina Neogi, a rheumatologist at Boston University. “There are early changes [seen with MRI] that are not picked up on radiographs, but we don’t yet have a standardized, validated definition of an earlier stage” on MRI, Dr. Neogi said in an interview.

Dr. Hunter said that he has received research support from AstraZeneca, DJO Inc. (DonJoy), Eli Lilly & Co., Merck & Co., Pfizer Inc., Stryker Corp., and Wyeth. Eight of the other members of the working group also provided disclosures, whereas the remaining seven members said they had no disclosures. Dr. Neogi had no disclosures.

BOSTON – Physical examination is still the gold standard for patients with vascular injury of the extremities, and can reduce unnecessary imaging in the majority of patients. But when imaging is called for, multidetector CT angiography is a highly sensitive and specific noninvasive option, said Dr. Kenji Inaba.

In a prospective study involving 73 patients with extremity trauma but uncertain signs of vascular injury, multidetector CT angiography (MCTA) flagged 24 injuries, all but 1 of which were confirmed in the operating room, Dr. Inaba said at the annual meeting of the American Association for the Surgery of Trauma.

“There are a lot of potential advantages to using CT angio: It’s widely available everywhere using preexisting hardware and software, it’s fast and becoming faster, and it’s available 24 hours a day without any delay from calling the interventional radiology team in,” said Dr. Inaba from the division of trauma and surgical critical care at the Los Angeles County Hospital/University of Southern California Medical Center.

Because the technique is not performed under a sterile field, it simplifies patient monitoring, and it produces “surgeon-friendly,” three-dimensional multiplanar images.

“Not only does it let us look at the vasculature, it also lets us look at soft tissues and all the bone structures as well. Unlike conventional angio, it doesn’t need a central arterial catheterization – all the contrast is given through peripheral venous access,” Dr. Inaba said.

He and his colleagues took a prospective look at the ability of MCTA to detect arterial injuries in the arms and legs. They studied patients aged 16 and older treated from January 2009 to August 2010 who presented with either penetrating injury, blunt crush, or long bone fracture or dislocation. Arm injuries could be anywhere down to the wrist, and leg injuries were anywhere down to the ankle.

A total of 635 patients were assigned to one of three treatment groups based on findings at physical examination. Those with hard signs of vascular injury (35 patients) were sent into surgery. Hard signs were defined as absent pulses, active hemorrhage, expanding/pulsatile hematoma, bruit or thrill, or shock unresponsive to resuscitation.

Those with no signs (527 patients) were put on observation for a minimum of 24 hours. Patients were considered to have no vascular injury signs if they had asymptomatic limbs and an ankle-brachial index (ABI) or a brachial-brachial index (BBI) of 0.9 or greater.

The remaining 73 patients had “soft” signs, such as venous oozing, nonexpanding or nonpulsatile hematoma, diminished pulses, or an abnormal ankle-brachial/brachial-brachial index. These patients underwent MCTA.

The patients underwent a total of 89 MCTA studies. The mean age was 30.3 years (range, 16-77); 88% were male; and 70% had penetrating injuries. The mean injury severity score was 10 plus or minus 8.1, and 38% of the patients had an abbreviated injury score of 3 or higher. Nearly half of all injuries were to the thigh. Other sites were the upper arm, knee, groin, shoulder/axilla, forearm, elbow, and calf.

Indications for MCTA included nonexpanding or nonpulsatile hematoma or an abnormal ABI or BBI (in 35.6% each), venous oozing in 21.9%, diminished pulses in 19.2%, and proximity of injury to a major vessel in 15.1%; some patients had more than one indication. Imaging for proximity was not one of the study indications, Dr. Inaba noted. The investigators classified the MCTA findings as either nondiagnostic, negative, or positive. Seven of the 89 studies were deemed to be nondiagnostic: 5 because of retained shotgun pellets or bullets causing artifacts that obscured potential injuries, and 2 because of technical problems that occurred with unfamiliar equipment in the new Los Angeles County facility during the early months of the study. These patients underwent conventional angiography, and there were no missed diagnoses, Dr. Inaba said.

Most of the MCTA studies (58) were negative. The patients were followed for a minimum of 24 hours (range, 1-41 days), and none had clinically significant missed injuries.

The remaining 24 studies were positive, and all but 1, a posterior tibular injury, were confirmed in the operating room.

“CT angio was not only able to locate the site of the injury, but it was also able to well characterize the injury itself,” Dr. Inaba said.

Limitations of the study included a lack of confirmatory imaging in the patients with negative studies because of the cost, time, and unjustifiable extra radiation exposure. In addition, 21% of these patients were sent home after 24 hours of observation, and it’s possible that CT angiography missed injuries that were later picked up at another hospital. The investigators also relied on final radiology reports rather than de novo blinded readings.

“These CT scanners are improving on a daily basis, and there’s true concern that we may be detecting clinically nonsignificant injuries,” he added.

Although Dr. Inaba said that the study showed MCTA sensitivity and specificity for vascular injury to be 100% each, the inconclusive study results indicate that neither could be 100%, said Dr. David Spain of the division of trauma/critical care at Stanford (Calif.) University Hospital. He was the invited discussant.

“The sensitivity and specificity analysis isn’t just for CTA. It’s actually for a structured physical exam followed by a CTA,” Dr. Spain commented.

The study was internally funded. The authors said they had no conflicts of interest.

BOSTON – Physical examination is still the gold standard for patients with vascular injury of the extremities, and can reduce unnecessary imaging in the majority of patients. But when imaging is called for, multidetector CT angiography is a highly sensitive and specific noninvasive option, said Dr. Kenji Inaba.

In a prospective study involving 73 patients with extremity trauma but uncertain signs of vascular injury, multidetector CT angiography (MCTA) flagged 24 injuries, all but 1 of which were confirmed in the operating room, Dr. Inaba said at the annual meeting of the American Association for the Surgery of Trauma.

“There are a lot of potential advantages to using CT angio: It’s widely available everywhere using preexisting hardware and software, it’s fast and becoming faster, and it’s available 24 hours a day without any delay from calling the interventional radiology team in,” said Dr. Inaba from the division of trauma and surgical critical care at the Los Angeles County Hospital/University of Southern California Medical Center.

Because the technique is not performed under a sterile field, it simplifies patient monitoring, and it produces “surgeon-friendly,” three-dimensional multiplanar images.

“Not only does it let us look at the vasculature, it also lets us look at soft tissues and all the bone structures as well. Unlike conventional angio, it doesn’t need a central arterial catheterization – all the contrast is given through peripheral venous access,” Dr. Inaba said.

He and his colleagues took a prospective look at the ability of MCTA to detect arterial injuries in the arms and legs. They studied patients aged 16 and older treated from January 2009 to August 2010 who presented with either penetrating injury, blunt crush, or long bone fracture or dislocation. Arm injuries could be anywhere down to the wrist, and leg injuries were anywhere down to the ankle.

A total of 635 patients were assigned to one of three treatment groups based on findings at physical examination. Those with hard signs of vascular injury (35 patients) were sent into surgery. Hard signs were defined as absent pulses, active hemorrhage, expanding/pulsatile hematoma, bruit or thrill, or shock unresponsive to resuscitation.

Those with no signs (527 patients) were put on observation for a minimum of 24 hours. Patients were considered to have no vascular injury signs if they had asymptomatic limbs and an ankle-brachial index (ABI) or a brachial-brachial index (BBI) of 0.9 or greater.

The remaining 73 patients had “soft” signs, such as venous oozing, nonexpanding or nonpulsatile hematoma, diminished pulses, or an abnormal ankle-brachial/brachial-brachial index. These patients underwent MCTA.

The patients underwent a total of 89 MCTA studies. The mean age was 30.3 years (range, 16-77); 88% were male; and 70% had penetrating injuries. The mean injury severity score was 10 plus or minus 8.1, and 38% of the patients had an abbreviated injury score of 3 or higher. Nearly half of all injuries were to the thigh. Other sites were the upper arm, knee, groin, shoulder/axilla, forearm, elbow, and calf.

Indications for MCTA included nonexpanding or nonpulsatile hematoma or an abnormal ABI or BBI (in 35.6% each), venous oozing in 21.9%, diminished pulses in 19.2%, and proximity of injury to a major vessel in 15.1%; some patients had more than one indication. Imaging for proximity was not one of the study indications, Dr. Inaba noted. The investigators classified the MCTA findings as either nondiagnostic, negative, or positive. Seven of the 89 studies were deemed to be nondiagnostic: 5 because of retained shotgun pellets or bullets causing artifacts that obscured potential injuries, and 2 because of technical problems that occurred with unfamiliar equipment in the new Los Angeles County facility during the early months of the study. These patients underwent conventional angiography, and there were no missed diagnoses, Dr. Inaba said.

Most of the MCTA studies (58) were negative. The patients were followed for a minimum of 24 hours (range, 1-41 days), and none had clinically significant missed injuries.

The remaining 24 studies were positive, and all but 1, a posterior tibular injury, were confirmed in the operating room.

“CT angio was not only able to locate the site of the injury, but it was also able to well characterize the injury itself,” Dr. Inaba said.

Limitations of the study included a lack of confirmatory imaging in the patients with negative studies because of the cost, time, and unjustifiable extra radiation exposure. In addition, 21% of these patients were sent home after 24 hours of observation, and it’s possible that CT angiography missed injuries that were later picked up at another hospital. The investigators also relied on final radiology reports rather than de novo blinded readings.

“These CT scanners are improving on a daily basis, and there’s true concern that we may be detecting clinically nonsignificant injuries,” he added.

Although Dr. Inaba said that the study showed MCTA sensitivity and specificity for vascular injury to be 100% each, the inconclusive study results indicate that neither could be 100%, said Dr. David Spain of the division of trauma/critical care at Stanford (Calif.) University Hospital. He was the invited discussant.

“The sensitivity and specificity analysis isn’t just for CTA. It’s actually for a structured physical exam followed by a CTA,” Dr. Spain commented.

The study was internally funded. The authors said they had no conflicts of interest.

BOSTON – Physical examination is still the gold standard for patients with vascular injury of the extremities, and can reduce unnecessary imaging in the majority of patients. But when imaging is called for, multidetector CT angiography is a highly sensitive and specific noninvasive option, said Dr. Kenji Inaba.

In a prospective study involving 73 patients with extremity trauma but uncertain signs of vascular injury, multidetector CT angiography (MCTA) flagged 24 injuries, all but 1 of which were confirmed in the operating room, Dr. Inaba said at the annual meeting of the American Association for the Surgery of Trauma.

“There are a lot of potential advantages to using CT angio: It’s widely available everywhere using preexisting hardware and software, it’s fast and becoming faster, and it’s available 24 hours a day without any delay from calling the interventional radiology team in,” said Dr. Inaba from the division of trauma and surgical critical care at the Los Angeles County Hospital/University of Southern California Medical Center.

Because the technique is not performed under a sterile field, it simplifies patient monitoring, and it produces “surgeon-friendly,” three-dimensional multiplanar images.

“Not only does it let us look at the vasculature, it also lets us look at soft tissues and all the bone structures as well. Unlike conventional angio, it doesn’t need a central arterial catheterization – all the contrast is given through peripheral venous access,” Dr. Inaba said.

He and his colleagues took a prospective look at the ability of MCTA to detect arterial injuries in the arms and legs. They studied patients aged 16 and older treated from January 2009 to August 2010 who presented with either penetrating injury, blunt crush, or long bone fracture or dislocation. Arm injuries could be anywhere down to the wrist, and leg injuries were anywhere down to the ankle.

A total of 635 patients were assigned to one of three treatment groups based on findings at physical examination. Those with hard signs of vascular injury (35 patients) were sent into surgery. Hard signs were defined as absent pulses, active hemorrhage, expanding/pulsatile hematoma, bruit or thrill, or shock unresponsive to resuscitation.

Those with no signs (527 patients) were put on observation for a minimum of 24 hours. Patients were considered to have no vascular injury signs if they had asymptomatic limbs and an ankle-brachial index (ABI) or a brachial-brachial index (BBI) of 0.9 or greater.

The remaining 73 patients had “soft” signs, such as venous oozing, nonexpanding or nonpulsatile hematoma, diminished pulses, or an abnormal ankle-brachial/brachial-brachial index. These patients underwent MCTA.

The patients underwent a total of 89 MCTA studies. The mean age was 30.3 years (range, 16-77); 88% were male; and 70% had penetrating injuries. The mean injury severity score was 10 plus or minus 8.1, and 38% of the patients had an abbreviated injury score of 3 or higher. Nearly half of all injuries were to the thigh. Other sites were the upper arm, knee, groin, shoulder/axilla, forearm, elbow, and calf.

Indications for MCTA included nonexpanding or nonpulsatile hematoma or an abnormal ABI or BBI (in 35.6% each), venous oozing in 21.9%, diminished pulses in 19.2%, and proximity of injury to a major vessel in 15.1%; some patients had more than one indication. Imaging for proximity was not one of the study indications, Dr. Inaba noted. The investigators classified the MCTA findings as either nondiagnostic, negative, or positive. Seven of the 89 studies were deemed to be nondiagnostic: 5 because of retained shotgun pellets or bullets causing artifacts that obscured potential injuries, and 2 because of technical problems that occurred with unfamiliar equipment in the new Los Angeles County facility during the early months of the study. These patients underwent conventional angiography, and there were no missed diagnoses, Dr. Inaba said.

Most of the MCTA studies (58) were negative. The patients were followed for a minimum of 24 hours (range, 1-41 days), and none had clinically significant missed injuries.

The remaining 24 studies were positive, and all but 1, a posterior tibular injury, were confirmed in the operating room.

“CT angio was not only able to locate the site of the injury, but it was also able to well characterize the injury itself,” Dr. Inaba said.

Limitations of the study included a lack of confirmatory imaging in the patients with negative studies because of the cost, time, and unjustifiable extra radiation exposure. In addition, 21% of these patients were sent home after 24 hours of observation, and it’s possible that CT angiography missed injuries that were later picked up at another hospital. The investigators also relied on final radiology reports rather than de novo blinded readings.

“These CT scanners are improving on a daily basis, and there’s true concern that we may be detecting clinically nonsignificant injuries,” he added.

Although Dr. Inaba said that the study showed MCTA sensitivity and specificity for vascular injury to be 100% each, the inconclusive study results indicate that neither could be 100%, said Dr. David Spain of the division of trauma/critical care at Stanford (Calif.) University Hospital. He was the invited discussant.

“The sensitivity and specificity analysis isn’t just for CTA. It’s actually for a structured physical exam followed by a CTA,” Dr. Spain commented.

The study was internally funded. The authors said they had no conflicts of interest.

WASHINGTON – While the use of magnetic resonance imaging as a screening tool for breast cancer has increased significantly over the past decade, there is still little evidence of its clinical benefits and cost-effectiveness, according to a panel of experts who addressed a capacity crowd at the annual clinical congress of the American College of Surgeons.

Patients at high risk of developing breast cancer (e.g., those with BRCA mutations or a greater than 20% risk of developing breast cancer during their lifetime) could benefit from breast MRI. The panel, however, pointed to a wide range of U.S., Canadian, and European studies showing that there is no evidence that MRI improves breast cancer survival, and it increases the rate of mastectomies. The panel members included Dr. Elisa R. Port and Dr. Monica Morrow, both of Memorial Sloan-Kettering Cancer Center in New York, Dr. Isabelle Bedrosian of MD Anderson Cancer Center in Houston, and Dr. Richard J. Bleicher of Fox Chase Cancer Center in Philadelphia.

The American Cancer Society and the National Comprehensive Cancer Network have developed MRI screening guidelines to distinguish which groups of patients should or should not be screened. However, there are very few data thus far to indicate just when to start or stop screening, or how often to perform screening, said Dr. Bedrosian.

“There are no data on the impact of MRI screening on survival outcomes,” she said, noting that the data to support MRI screening in terms of outcomes are based on disease stage migration, not survival.

She added that there are very few data about the cost-effectiveness of breast MRI screening. Patient age, BRCA gene mutations, breast density, and the cost of MRI must all be factored into the cost-effectiveness of MRI screening. The data show that MRI screening is more cost effective for higher-risk patients, but the panel wondered whether breast MRI screenings could be contributing to the nation’s rising health care costs.

There are currently 70 million women in the United States between the ages of 30 and 70. Of those, 1% are at high risk of developing breast cancer and are eligible for screening, which translates to a potential 1 million MRI screenings per year, said the panel.

“The most troubling finding is that it causes us to think about breast cancer the way we thought about it in the 1970s, the 1980s, and the early 1990s – that the disease burden in the breast is the sole or primary determinant of breast cancer outcome,” said Dr. Morrow. “The modern era tells us that’s really not true.”

In addition, she mentioned two retrospective studies (one in the United States and the other from the Netherlands Cancer Institute) that showed no decrease in unplanned mastectomy for patients who had preoperative MRI.

To answer the question of whether or not obtaining an MRI increases the likelihood of obtaining negative margins, Dr. Morrow summarized the results of four retrospective studies involving more than 2,500 patients. “The studies showed no statistically significant benefit in terms of reducing positive margins with MRI,” she said.

Another prospective randomized trial of 1,600 women showed that the net effect of MRI was a slightly higher rate of mastectomy in patients who had an MRI preoperatively, but no reduction in the need for further surgery.

Dr. Morrow added that in patients who have unifocal cancer, MRI can’t underestimate the extent of disease but instead overestimates the extent of disease in a third of the patients. In the case of multifocal or multicentric disease, MRI is accurate in a third of the patients, it overestimates the disease in another third, and it misses the disease a third of the time.

“There’s no possibility that MRI will improve breast cancer survival,” Dr. Morrow said. It takes a difference in local failure rates of greater than 10% at 5 years post treatment to see a survival difference in 15 years, she added. “Current rates of local recurrence at 10 years are less than 10%, and there should be no expectation that MRI will change survival.”

Medicare data show that the number of MRIs (all types) performed has increased over the past decade. While the total cost of treating breast cancer patients in the United States is increasing at 4% per year, the imaging costs are increasing at 10% a year, said Dr. Bleicher.

Although there are no national data showing what percentage of health care costs is attributable to breast MRIs, “one of the things that’s not in dispute [is that] breast MRI usage in breast cancer patients is increasing,” and its contribution to rising health care costs is “highly suggestive,” he added.

Furthermore, fear of lawsuits among surgeons and radiologists also influences the decision to order these tests.

“So what can we do?” asked Dr. Bleicher. “Always do what’s best for the patient, [and] you need to document your rationale. MRI is indeed a valuable tool, but we really do need to define its indications both to justify the cost involved and to clarify when not performing it is true breach of duty to the patient.”

The panel concluded that there is a need to establish evidence-based criteria for ordering MRIs in different clinical scenarios. “The potential research applications of MRI should not be confused with routine clinical practice,” said Dr. Morrow.

“MRI is not emerging – it has fully emerged – and in some respects, the train has already left the station,” said Dr. Port. “I think what we need to do at this point is really re-establish definitive guidelines for [MRI] use in women with newly diagnosed breast cancer for whom there are no clear-cut guidelines and for whom practice patterns range widely.”

The panel members reported no relevant conflicts of interest.

WASHINGTON – While the use of magnetic resonance imaging as a screening tool for breast cancer has increased significantly over the past decade, there is still little evidence of its clinical benefits and cost-effectiveness, according to a panel of experts who addressed a capacity crowd at the annual clinical congress of the American College of Surgeons.

Patients at high risk of developing breast cancer (e.g., those with BRCA mutations or a greater than 20% risk of developing breast cancer during their lifetime) could benefit from breast MRI. The panel, however, pointed to a wide range of U.S., Canadian, and European studies showing that there is no evidence that MRI improves breast cancer survival, and it increases the rate of mastectomies. The panel members included Dr. Elisa R. Port and Dr. Monica Morrow, both of Memorial Sloan-Kettering Cancer Center in New York, Dr. Isabelle Bedrosian of MD Anderson Cancer Center in Houston, and Dr. Richard J. Bleicher of Fox Chase Cancer Center in Philadelphia.

The American Cancer Society and the National Comprehensive Cancer Network have developed MRI screening guidelines to distinguish which groups of patients should or should not be screened. However, there are very few data thus far to indicate just when to start or stop screening, or how often to perform screening, said Dr. Bedrosian.

“There are no data on the impact of MRI screening on survival outcomes,” she said, noting that the data to support MRI screening in terms of outcomes are based on disease stage migration, not survival.

She added that there are very few data about the cost-effectiveness of breast MRI screening. Patient age, BRCA gene mutations, breast density, and the cost of MRI must all be factored into the cost-effectiveness of MRI screening. The data show that MRI screening is more cost effective for higher-risk patients, but the panel wondered whether breast MRI screenings could be contributing to the nation’s rising health care costs.

There are currently 70 million women in the United States between the ages of 30 and 70. Of those, 1% are at high risk of developing breast cancer and are eligible for screening, which translates to a potential 1 million MRI screenings per year, said the panel.

“The most troubling finding is that it causes us to think about breast cancer the way we thought about it in the 1970s, the 1980s, and the early 1990s – that the disease burden in the breast is the sole or primary determinant of breast cancer outcome,” said Dr. Morrow. “The modern era tells us that’s really not true.”

In addition, she mentioned two retrospective studies (one in the United States and the other from the Netherlands Cancer Institute) that showed no decrease in unplanned mastectomy for patients who had preoperative MRI.

To answer the question of whether or not obtaining an MRI increases the likelihood of obtaining negative margins, Dr. Morrow summarized the results of four retrospective studies involving more than 2,500 patients. “The studies showed no statistically significant benefit in terms of reducing positive margins with MRI,” she said.

Another prospective randomized trial of 1,600 women showed that the net effect of MRI was a slightly higher rate of mastectomy in patients who had an MRI preoperatively, but no reduction in the need for further surgery.

Dr. Morrow added that in patients who have unifocal cancer, MRI can’t underestimate the extent of disease but instead overestimates the extent of disease in a third of the patients. In the case of multifocal or multicentric disease, MRI is accurate in a third of the patients, it overestimates the disease in another third, and it misses the disease a third of the time.

“There’s no possibility that MRI will improve breast cancer survival,” Dr. Morrow said. It takes a difference in local failure rates of greater than 10% at 5 years post treatment to see a survival difference in 15 years, she added. “Current rates of local recurrence at 10 years are less than 10%, and there should be no expectation that MRI will change survival.”

Medicare data show that the number of MRIs (all types) performed has increased over the past decade. While the total cost of treating breast cancer patients in the United States is increasing at 4% per year, the imaging costs are increasing at 10% a year, said Dr. Bleicher.

Although there are no national data showing what percentage of health care costs is attributable to breast MRIs, “one of the things that’s not in dispute [is that] breast MRI usage in breast cancer patients is increasing,” and its contribution to rising health care costs is “highly suggestive,” he added.

Furthermore, fear of lawsuits among surgeons and radiologists also influences the decision to order these tests.

“So what can we do?” asked Dr. Bleicher. “Always do what’s best for the patient, [and] you need to document your rationale. MRI is indeed a valuable tool, but we really do need to define its indications both to justify the cost involved and to clarify when not performing it is true breach of duty to the patient.”

The panel concluded that there is a need to establish evidence-based criteria for ordering MRIs in different clinical scenarios. “The potential research applications of MRI should not be confused with routine clinical practice,” said Dr. Morrow.

“MRI is not emerging – it has fully emerged – and in some respects, the train has already left the station,” said Dr. Port. “I think what we need to do at this point is really re-establish definitive guidelines for [MRI] use in women with newly diagnosed breast cancer for whom there are no clear-cut guidelines and for whom practice patterns range widely.”

The panel members reported no relevant conflicts of interest.

WASHINGTON – While the use of magnetic resonance imaging as a screening tool for breast cancer has increased significantly over the past decade, there is still little evidence of its clinical benefits and cost-effectiveness, according to a panel of experts who addressed a capacity crowd at the annual clinical congress of the American College of Surgeons.

Patients at high risk of developing breast cancer (e.g., those with BRCA mutations or a greater than 20% risk of developing breast cancer during their lifetime) could benefit from breast MRI. The panel, however, pointed to a wide range of U.S., Canadian, and European studies showing that there is no evidence that MRI improves breast cancer survival, and it increases the rate of mastectomies. The panel members included Dr. Elisa R. Port and Dr. Monica Morrow, both of Memorial Sloan-Kettering Cancer Center in New York, Dr. Isabelle Bedrosian of MD Anderson Cancer Center in Houston, and Dr. Richard J. Bleicher of Fox Chase Cancer Center in Philadelphia.

The American Cancer Society and the National Comprehensive Cancer Network have developed MRI screening guidelines to distinguish which groups of patients should or should not be screened. However, there are very few data thus far to indicate just when to start or stop screening, or how often to perform screening, said Dr. Bedrosian.

“There are no data on the impact of MRI screening on survival outcomes,” she said, noting that the data to support MRI screening in terms of outcomes are based on disease stage migration, not survival.

She added that there are very few data about the cost-effectiveness of breast MRI screening. Patient age, BRCA gene mutations, breast density, and the cost of MRI must all be factored into the cost-effectiveness of MRI screening. The data show that MRI screening is more cost effective for higher-risk patients, but the panel wondered whether breast MRI screenings could be contributing to the nation’s rising health care costs.

There are currently 70 million women in the United States between the ages of 30 and 70. Of those, 1% are at high risk of developing breast cancer and are eligible for screening, which translates to a potential 1 million MRI screenings per year, said the panel.

“The most troubling finding is that it causes us to think about breast cancer the way we thought about it in the 1970s, the 1980s, and the early 1990s – that the disease burden in the breast is the sole or primary determinant of breast cancer outcome,” said Dr. Morrow. “The modern era tells us that’s really not true.”

In addition, she mentioned two retrospective studies (one in the United States and the other from the Netherlands Cancer Institute) that showed no decrease in unplanned mastectomy for patients who had preoperative MRI.

To answer the question of whether or not obtaining an MRI increases the likelihood of obtaining negative margins, Dr. Morrow summarized the results of four retrospective studies involving more than 2,500 patients. “The studies showed no statistically significant benefit in terms of reducing positive margins with MRI,” she said.

Another prospective randomized trial of 1,600 women showed that the net effect of MRI was a slightly higher rate of mastectomy in patients who had an MRI preoperatively, but no reduction in the need for further surgery.

Dr. Morrow added that in patients who have unifocal cancer, MRI can’t underestimate the extent of disease but instead overestimates the extent of disease in a third of the patients. In the case of multifocal or multicentric disease, MRI is accurate in a third of the patients, it overestimates the disease in another third, and it misses the disease a third of the time.

“There’s no possibility that MRI will improve breast cancer survival,” Dr. Morrow said. It takes a difference in local failure rates of greater than 10% at 5 years post treatment to see a survival difference in 15 years, she added. “Current rates of local recurrence at 10 years are less than 10%, and there should be no expectation that MRI will change survival.”

Medicare data show that the number of MRIs (all types) performed has increased over the past decade. While the total cost of treating breast cancer patients in the United States is increasing at 4% per year, the imaging costs are increasing at 10% a year, said Dr. Bleicher.

Although there are no national data showing what percentage of health care costs is attributable to breast MRIs, “one of the things that’s not in dispute [is that] breast MRI usage in breast cancer patients is increasing,” and its contribution to rising health care costs is “highly suggestive,” he added.

Furthermore, fear of lawsuits among surgeons and radiologists also influences the decision to order these tests.

“So what can we do?” asked Dr. Bleicher. “Always do what’s best for the patient, [and] you need to document your rationale. MRI is indeed a valuable tool, but we really do need to define its indications both to justify the cost involved and to clarify when not performing it is true breach of duty to the patient.”

The panel concluded that there is a need to establish evidence-based criteria for ordering MRIs in different clinical scenarios. “The potential research applications of MRI should not be confused with routine clinical practice,” said Dr. Morrow.

“MRI is not emerging – it has fully emerged – and in some respects, the train has already left the station,” said Dr. Port. “I think what we need to do at this point is really re-establish definitive guidelines for [MRI] use in women with newly diagnosed breast cancer for whom there are no clear-cut guidelines and for whom practice patterns range widely.”

The panel members reported no relevant conflicts of interest.

BRUSSELS – Analysis of plain x-ray images of knee joints from 60 patients with osteoarthritis confirmed that a novel method for assessing bone trabecular structure adjacent to knee joints provides a reliable prediction of future disease progression.

Assessment of bone trabecular integrity by fractal signature analysis “provides an osteoarthritis imaging biomarker that is a prognostic marker of knee osteoarthritis progression,” Dr. Virginia Byers Kraus said at the annual World Congress on Osteoarthritis.

Baseline bone trabecular integrity predicted roughly 85% of the change in joint space area during 2 years of follow-up in patients with osteoarthritis (OA). The new study, which used x-rays from 60 patients with OA and 67 controls, is the second report to document the prognostic accuracy of fractal signature analysis of bone trabecular integrity in OA patients. The first report, also from Dr. Kraus and her associates, came out last year, and involved 138 OA patients who were followed for 3 years (Arthritis Rheum. 2009;60:3711-22).

“The next step is to compare fractal signature analysis head to head with MRI and look at its ability to predict MRI changes” in OA patients, and “its ability to identify OA in the preradiographic stage,” Dr. Kraus said in an interview.

Fractal signature analysis of bone trabecular integrity using x-ray images “gives you the ability to more fully phenotype patients than we’ve been able to, and it is less costly than MRI,” said Dr. Kraus, a rheumatologist and professor of medicine at Duke University in Durham, N.C. “It’s very promising for identifying patients at high risk for progression in [an intervention] trial, and possibly to screen patients in the clinic.”

Fractal signature analysis evaluates the complexity of detail of a two-dimensional image. Researchers first reported using fractal signature analysis in 1991 to assess bone architecture in radiographs of OA joints. Past studies also successfully used the method to assess osteoporosis and arthritis of the spine, hip, wrists, hands, and knees before and after surgery. Fractal signature analysis has the major advantage of not being very sensitive to image-acquisition quality.

Although fractal signature analysis involves a complex statistical analysis of x-ray image data of bone structure adjacent to a patient’s knee joint, Dr. Kraus and her associates incorporated that analysis into “KneeAnalyzer” software developed by Optasia Medical, a British company. Now that the software exists, “it is easy to use. It’s just a tool to get at bone trabecular integrity. I think it can easily be widely adopted,” she said.

The new study used data collected in a non–therapeutic methods trial sponsored by Pfizer Inc. The data set included 60 women with knee OA, an average age of 58 years, and an average body mass index of 35.6 kg/m2. (All participants in this arm of the study had a BMI of at least 30.) The 67 women controls had an average age of 55 years, all had a BMI of 28 or less, and all had no knee symptoms, no radiographic signs of knee OA, and no history of knee fracture, surgery, or disease.

The researchers assessed bone trabecular integrity using fractal signature analysis on radiographs taken at baseline, and after 12 and 24 months. The results showed that baseline measurements in the vertical dimension of bone trabecular integrity predicted changes in joint space area at 12 and 24 months, and in joint space width at 24 months. Baseline measures in the horizontal dimension were not predictive. The predicted changes based on baseline bone trabecular integrity accounted for 85%-87% of the actual change in joint space area over 24 months, Dr. Kraus reported at the congress, which was organized by the Osteoarthritis Research Society International.

Analysis of baseline and follow-up measures in the control subjects allowed the researchers to attribute progression in patients to an OA-specific process and not as the result of aging.

Dr. Kraus said that she had no relevant disclosures. One coauthor is an employee of Optasia Medical, and Optasia provided the software used for the radiograph analyses. Another coauthor is an employee of Pfizer, and Pfizer supplied the database used in the study.

BRUSSELS – Analysis of plain x-ray images of knee joints from 60 patients with osteoarthritis confirmed that a novel method for assessing bone trabecular structure adjacent to knee joints provides a reliable prediction of future disease progression.

Assessment of bone trabecular integrity by fractal signature analysis “provides an osteoarthritis imaging biomarker that is a prognostic marker of knee osteoarthritis progression,” Dr. Virginia Byers Kraus said at the annual World Congress on Osteoarthritis.

Baseline bone trabecular integrity predicted roughly 85% of the change in joint space area during 2 years of follow-up in patients with osteoarthritis (OA). The new study, which used x-rays from 60 patients with OA and 67 controls, is the second report to document the prognostic accuracy of fractal signature analysis of bone trabecular integrity in OA patients. The first report, also from Dr. Kraus and her associates, came out last year, and involved 138 OA patients who were followed for 3 years (Arthritis Rheum. 2009;60:3711-22).

“The next step is to compare fractal signature analysis head to head with MRI and look at its ability to predict MRI changes” in OA patients, and “its ability to identify OA in the preradiographic stage,” Dr. Kraus said in an interview.

Fractal signature analysis of bone trabecular integrity using x-ray images “gives you the ability to more fully phenotype patients than we’ve been able to, and it is less costly than MRI,” said Dr. Kraus, a rheumatologist and professor of medicine at Duke University in Durham, N.C. “It’s very promising for identifying patients at high risk for progression in [an intervention] trial, and possibly to screen patients in the clinic.”

Fractal signature analysis evaluates the complexity of detail of a two-dimensional image. Researchers first reported using fractal signature analysis in 1991 to assess bone architecture in radiographs of OA joints. Past studies also successfully used the method to assess osteoporosis and arthritis of the spine, hip, wrists, hands, and knees before and after surgery. Fractal signature analysis has the major advantage of not being very sensitive to image-acquisition quality.

Although fractal signature analysis involves a complex statistical analysis of x-ray image data of bone structure adjacent to a patient’s knee joint, Dr. Kraus and her associates incorporated that analysis into “KneeAnalyzer” software developed by Optasia Medical, a British company. Now that the software exists, “it is easy to use. It’s just a tool to get at bone trabecular integrity. I think it can easily be widely adopted,” she said.

The new study used data collected in a non–therapeutic methods trial sponsored by Pfizer Inc. The data set included 60 women with knee OA, an average age of 58 years, and an average body mass index of 35.6 kg/m2. (All participants in this arm of the study had a BMI of at least 30.) The 67 women controls had an average age of 55 years, all had a BMI of 28 or less, and all had no knee symptoms, no radiographic signs of knee OA, and no history of knee fracture, surgery, or disease.

The researchers assessed bone trabecular integrity using fractal signature analysis on radiographs taken at baseline, and after 12 and 24 months. The results showed that baseline measurements in the vertical dimension of bone trabecular integrity predicted changes in joint space area at 12 and 24 months, and in joint space width at 24 months. Baseline measures in the horizontal dimension were not predictive. The predicted changes based on baseline bone trabecular integrity accounted for 85%-87% of the actual change in joint space area over 24 months, Dr. Kraus reported at the congress, which was organized by the Osteoarthritis Research Society International.

Analysis of baseline and follow-up measures in the control subjects allowed the researchers to attribute progression in patients to an OA-specific process and not as the result of aging.

Dr. Kraus said that she had no relevant disclosures. One coauthor is an employee of Optasia Medical, and Optasia provided the software used for the radiograph analyses. Another coauthor is an employee of Pfizer, and Pfizer supplied the database used in the study.

BRUSSELS – Analysis of plain x-ray images of knee joints from 60 patients with osteoarthritis confirmed that a novel method for assessing bone trabecular structure adjacent to knee joints provides a reliable prediction of future disease progression.

Assessment of bone trabecular integrity by fractal signature analysis “provides an osteoarthritis imaging biomarker that is a prognostic marker of knee osteoarthritis progression,” Dr. Virginia Byers Kraus said at the annual World Congress on Osteoarthritis.

Baseline bone trabecular integrity predicted roughly 85% of the change in joint space area during 2 years of follow-up in patients with osteoarthritis (OA). The new study, which used x-rays from 60 patients with OA and 67 controls, is the second report to document the prognostic accuracy of fractal signature analysis of bone trabecular integrity in OA patients. The first report, also from Dr. Kraus and her associates, came out last year, and involved 138 OA patients who were followed for 3 years (Arthritis Rheum. 2009;60:3711-22).

“The next step is to compare fractal signature analysis head to head with MRI and look at its ability to predict MRI changes” in OA patients, and “its ability to identify OA in the preradiographic stage,” Dr. Kraus said in an interview.

Fractal signature analysis of bone trabecular integrity using x-ray images “gives you the ability to more fully phenotype patients than we’ve been able to, and it is less costly than MRI,” said Dr. Kraus, a rheumatologist and professor of medicine at Duke University in Durham, N.C. “It’s very promising for identifying patients at high risk for progression in [an intervention] trial, and possibly to screen patients in the clinic.”

Fractal signature analysis evaluates the complexity of detail of a two-dimensional image. Researchers first reported using fractal signature analysis in 1991 to assess bone architecture in radiographs of OA joints. Past studies also successfully used the method to assess osteoporosis and arthritis of the spine, hip, wrists, hands, and knees before and after surgery. Fractal signature analysis has the major advantage of not being very sensitive to image-acquisition quality.

Although fractal signature analysis involves a complex statistical analysis of x-ray image data of bone structure adjacent to a patient’s knee joint, Dr. Kraus and her associates incorporated that analysis into “KneeAnalyzer” software developed by Optasia Medical, a British company. Now that the software exists, “it is easy to use. It’s just a tool to get at bone trabecular integrity. I think it can easily be widely adopted,” she said.

The new study used data collected in a non–therapeutic methods trial sponsored by Pfizer Inc. The data set included 60 women with knee OA, an average age of 58 years, and an average body mass index of 35.6 kg/m2. (All participants in this arm of the study had a BMI of at least 30.) The 67 women controls had an average age of 55 years, all had a BMI of 28 or less, and all had no knee symptoms, no radiographic signs of knee OA, and no history of knee fracture, surgery, or disease.

The researchers assessed bone trabecular integrity using fractal signature analysis on radiographs taken at baseline, and after 12 and 24 months. The results showed that baseline measurements in the vertical dimension of bone trabecular integrity predicted changes in joint space area at 12 and 24 months, and in joint space width at 24 months. Baseline measures in the horizontal dimension were not predictive. The predicted changes based on baseline bone trabecular integrity accounted for 85%-87% of the actual change in joint space area over 24 months, Dr. Kraus reported at the congress, which was organized by the Osteoarthritis Research Society International.

Analysis of baseline and follow-up measures in the control subjects allowed the researchers to attribute progression in patients to an OA-specific process and not as the result of aging.

Dr. Kraus said that she had no relevant disclosures. One coauthor is an employee of Optasia Medical, and Optasia provided the software used for the radiograph analyses. Another coauthor is an employee of Pfizer, and Pfizer supplied the database used in the study.