Imaging

PHILADELPHIA – The American College of Cardiology Foundation and the American Heart Association have endorsed stepwise guidelines for using nuclear imaging to manage and diagnose heart failure, but they do not obviate the need for the hands-on patient examination, said Dr. Alfred Bove of Temple University, Philadelphia.

“The beginning of management of a patient with heart failure is clinical,” Dr. Bove said. “We have to understand the patient's status. I always think it's important to put a stethoscope there first.” That provides a basis for interpreting data generated by subsequent imaging, as called for in the ACCF/AHA guidelines (J. Am. Coll. Cardiol. 2009;53:1343-832), he said.

“The first thing we're trying to understand is both the etiology of ventricular dysfunction and actual function when a patient shows up with symptoms of congestive heart failure to determine whether it is ischemic, dilated, valvular, or congenital,” he said. “We need imaging to sort out these etiologies.”

Ejection fraction is a key measure to determine left ventricle function, as are left ventricle dimensions, he said. “We are always looking at diastolic dimensions in particular; the degree of hypertrophy; whether there's any evidence of coronary disease or coronary stenosis or valvular stenosis or insufficiency; and finally, with congenital heart disease, the presence of shunts.”

The guidelines first recommend obtaining a two-dimensional echocardiogram. “It will tell us what the ejection fraction is, and tell us about valve size and function,” he said

The guidelines then “jump” to radionuclide ventriculography to assess ejection fraction and volume. In a patient with ischemic cardiomyopathy, coronary arteriography can help evaluate indications for revascularization, he said.

In the patient with no history of coronary disease, myocardial perfusion imaging (MPI) can determine the presence of perfusion defects. “We can use that as a basis to go forward to do some further studies,” he said. But in the patient with nonischemic cardiomyopathy and no history of coronary disease, MPI can also have a high number of false-positive readings. “We're more interested here in getting ejection fraction and some measure of heart size from the imaging as well as perfusion,” Dr. Bove said.

The guidelines also call for appropriate follow-up with gated SPECT (single-photon emission CT) or MUGA (multiple gated acquisition) because echocardiography is inconclusive in about 20% of patients, particularly those who are obese or have large chests, Dr. Bove said. “In many cases [when] we see someone with borderline ejection fraction, we send that person for a gated scan and it comes back normal,” he said.

A gated SPECT or MUGA scan provides an “important second backup in left ventricle measures,” particularly in patients whose echocardiograms are of poor quality, he said.

In cases of suspected ischemic cardiomyopathy, the ACCF/AHA guidelines call for coronary CT angiography. “This has a very good negative predictive value,” Dr. Bove said. “If we get a negative CT angiogram, we can be pretty comfortable in saying this is not an ischemic cardiomyopathy.”

When the case mandates further study, MRI can help evaluate structural anomalies in the myocardium. “When there's a question of etiology in the absence of coronary disease, the MRI becomes very important in assessing the etiology of the myocardial dysfunction,” he said.

Dr. Bove disclosed that he is a consultant to Insight Telehealth Systems.

In cases of suspected ischemic cardiomyopathy, the guidelines call for coronary CT angiography.

Source DR. BOVE

PHILADELPHIA – The American College of Cardiology Foundation and the American Heart Association have endorsed stepwise guidelines for using nuclear imaging to manage and diagnose heart failure, but they do not obviate the need for the hands-on patient examination, said Dr. Alfred Bove of Temple University, Philadelphia.

“The beginning of management of a patient with heart failure is clinical,” Dr. Bove said. “We have to understand the patient's status. I always think it's important to put a stethoscope there first.” That provides a basis for interpreting data generated by subsequent imaging, as called for in the ACCF/AHA guidelines (J. Am. Coll. Cardiol. 2009;53:1343-832), he said.

“The first thing we're trying to understand is both the etiology of ventricular dysfunction and actual function when a patient shows up with symptoms of congestive heart failure to determine whether it is ischemic, dilated, valvular, or congenital,” he said. “We need imaging to sort out these etiologies.”

Ejection fraction is a key measure to determine left ventricle function, as are left ventricle dimensions, he said. “We are always looking at diastolic dimensions in particular; the degree of hypertrophy; whether there's any evidence of coronary disease or coronary stenosis or valvular stenosis or insufficiency; and finally, with congenital heart disease, the presence of shunts.”

The guidelines first recommend obtaining a two-dimensional echocardiogram. “It will tell us what the ejection fraction is, and tell us about valve size and function,” he said

The guidelines then “jump” to radionuclide ventriculography to assess ejection fraction and volume. In a patient with ischemic cardiomyopathy, coronary arteriography can help evaluate indications for revascularization, he said.

In the patient with no history of coronary disease, myocardial perfusion imaging (MPI) can determine the presence of perfusion defects. “We can use that as a basis to go forward to do some further studies,” he said. But in the patient with nonischemic cardiomyopathy and no history of coronary disease, MPI can also have a high number of false-positive readings. “We're more interested here in getting ejection fraction and some measure of heart size from the imaging as well as perfusion,” Dr. Bove said.

The guidelines also call for appropriate follow-up with gated SPECT (single-photon emission CT) or MUGA (multiple gated acquisition) because echocardiography is inconclusive in about 20% of patients, particularly those who are obese or have large chests, Dr. Bove said. “In many cases [when] we see someone with borderline ejection fraction, we send that person for a gated scan and it comes back normal,” he said.

A gated SPECT or MUGA scan provides an “important second backup in left ventricle measures,” particularly in patients whose echocardiograms are of poor quality, he said.

In cases of suspected ischemic cardiomyopathy, the ACCF/AHA guidelines call for coronary CT angiography. “This has a very good negative predictive value,” Dr. Bove said. “If we get a negative CT angiogram, we can be pretty comfortable in saying this is not an ischemic cardiomyopathy.”

When the case mandates further study, MRI can help evaluate structural anomalies in the myocardium. “When there's a question of etiology in the absence of coronary disease, the MRI becomes very important in assessing the etiology of the myocardial dysfunction,” he said.

Dr. Bove disclosed that he is a consultant to Insight Telehealth Systems.

In cases of suspected ischemic cardiomyopathy, the guidelines call for coronary CT angiography.

Source DR. BOVE

PHILADELPHIA – The American College of Cardiology Foundation and the American Heart Association have endorsed stepwise guidelines for using nuclear imaging to manage and diagnose heart failure, but they do not obviate the need for the hands-on patient examination, said Dr. Alfred Bove of Temple University, Philadelphia.

“The beginning of management of a patient with heart failure is clinical,” Dr. Bove said. “We have to understand the patient's status. I always think it's important to put a stethoscope there first.” That provides a basis for interpreting data generated by subsequent imaging, as called for in the ACCF/AHA guidelines (J. Am. Coll. Cardiol. 2009;53:1343-832), he said.

“The first thing we're trying to understand is both the etiology of ventricular dysfunction and actual function when a patient shows up with symptoms of congestive heart failure to determine whether it is ischemic, dilated, valvular, or congenital,” he said. “We need imaging to sort out these etiologies.”

Ejection fraction is a key measure to determine left ventricle function, as are left ventricle dimensions, he said. “We are always looking at diastolic dimensions in particular; the degree of hypertrophy; whether there's any evidence of coronary disease or coronary stenosis or valvular stenosis or insufficiency; and finally, with congenital heart disease, the presence of shunts.”

The guidelines first recommend obtaining a two-dimensional echocardiogram. “It will tell us what the ejection fraction is, and tell us about valve size and function,” he said

The guidelines then “jump” to radionuclide ventriculography to assess ejection fraction and volume. In a patient with ischemic cardiomyopathy, coronary arteriography can help evaluate indications for revascularization, he said.

In the patient with no history of coronary disease, myocardial perfusion imaging (MPI) can determine the presence of perfusion defects. “We can use that as a basis to go forward to do some further studies,” he said. But in the patient with nonischemic cardiomyopathy and no history of coronary disease, MPI can also have a high number of false-positive readings. “We're more interested here in getting ejection fraction and some measure of heart size from the imaging as well as perfusion,” Dr. Bove said.

The guidelines also call for appropriate follow-up with gated SPECT (single-photon emission CT) or MUGA (multiple gated acquisition) because echocardiography is inconclusive in about 20% of patients, particularly those who are obese or have large chests, Dr. Bove said. “In many cases [when] we see someone with borderline ejection fraction, we send that person for a gated scan and it comes back normal,” he said.

A gated SPECT or MUGA scan provides an “important second backup in left ventricle measures,” particularly in patients whose echocardiograms are of poor quality, he said.

In cases of suspected ischemic cardiomyopathy, the ACCF/AHA guidelines call for coronary CT angiography. “This has a very good negative predictive value,” Dr. Bove said. “If we get a negative CT angiogram, we can be pretty comfortable in saying this is not an ischemic cardiomyopathy.”

When the case mandates further study, MRI can help evaluate structural anomalies in the myocardium. “When there's a question of etiology in the absence of coronary disease, the MRI becomes very important in assessing the etiology of the myocardial dysfunction,” he said.

Dr. Bove disclosed that he is a consultant to Insight Telehealth Systems.

In cases of suspected ischemic cardiomyopathy, the guidelines call for coronary CT angiography.

Source DR. BOVE

Hormone therapy stabilized bone loss over a 2-year period in rheumatoid arthritis patients, as measured on digital x-ray radiogrammetry, according to a study published in Annals of the Rheumatic Diseases.

The study is important not only for finding that hormone therapy (HT) was effective, but because it depended on readings that detected losses of as little as 0.36%.

In contrast, plain radiographs, "the standard method for detection and quantification of joint destruction in RA," cannot detect bone loss of less than 30%, wrote Dr. Helena Forsblad-d’Elia and Dr. Hans Carlsten (Ann. Rheum. Dis. 2010 Nov. 3 [doi: 10.1136/ard.2010.137133]).

Dr. Forsblad-d’Elia and Dr. Carlsten, both of the center for bone and arthritis research at the University of Gothenburg (Sweden), looked at 88 postmenopausal women with radiographic joint destruction due to rheumatoid arthritis. Findings from earlier research by Dr. Forsblad-d’Elia has shown that RA is strongly associated with generalized osteoporosis (Ann. Rheum. Dis. 2003;62:617–23).

Patients were randomized to one of two groups. The first received HRT, which consisted of estradiol and norethisterone acetate, plus a daily dose of 500 mg calcium and 400 IU vitamin D. Controls received only the calcium and vitamin D.

Patients had digital x-ray radiogrammetry–bone mineral density (DXR-BMD) readings at baseline and at 2 years. A total of 13 women had ineligible DXR-BMD readings at baseline because of prostheses, osteosynthetic materials, the position of the hands or insufficient x-ray, wrote the authors. Another 25 patients did not complete the second DXR-BMD 2 years later.

That left a total of 50 women (23 HRT patients, 27 controls) to be included in the study analysis. The mean age of both groups was roughly 58 years, and both groups had a mean disease duration of greater than 10 years.

According to the researchers, at baseline, HT patients and controls had an identical mean DXR-BMD reading of 0.45 g/cm²; HRT patients had a standard deviation of 0.096, vs. 0.081 in the control group.

Two years later, HT patients’ mean reading was identical except for a tiny increase in the standard deviation, to 0.097, whereas control patients’ mean DXR-BMD was 0.44, with a standard deviation of 0.084.

The minute difference was insignificant for the HT group (–0.0015 ± 0.0078), but significant for controls, both in terms of change from baseline and difference from the HT group (–0.18 ± 0.038, P less than .05 for both comparisons).

Put another way, the decrease among HT patients from baseline was 0.36%, while the decrease from baseline for controls was 3.74% – more than 10 times greater.

"DXR-BMD has been proposed to be an outcome measure in monitoring treatments in early RA, and can predict future radiographic joint damage," concluded the authors. "So far, there is limited knowledge of DXR-BMD used as an outcome measure in randomized controlled trials in long-term RA."

Based on the current data, however, "we suggest that DXR-BMD could serve as an outcome measure in [randomized controlled trials] in long-standing RA," they wrote.

"Further studies on disease-modifying drugs are needed to assess its usability."

Dr. Forsblad-d’Elia and Dr. Carlsten said that this study was supported by several grants from rheumatology and other foundations; they added that they had no competing interests to disclose.

Hormone therapy stabilized bone loss over a 2-year period in rheumatoid arthritis patients, as measured on digital x-ray radiogrammetry, according to a study published in Annals of the Rheumatic Diseases.

The study is important not only for finding that hormone therapy (HT) was effective, but because it depended on readings that detected losses of as little as 0.36%.

In contrast, plain radiographs, "the standard method for detection and quantification of joint destruction in RA," cannot detect bone loss of less than 30%, wrote Dr. Helena Forsblad-d’Elia and Dr. Hans Carlsten (Ann. Rheum. Dis. 2010 Nov. 3 [doi: 10.1136/ard.2010.137133]).

Dr. Forsblad-d’Elia and Dr. Carlsten, both of the center for bone and arthritis research at the University of Gothenburg (Sweden), looked at 88 postmenopausal women with radiographic joint destruction due to rheumatoid arthritis. Findings from earlier research by Dr. Forsblad-d’Elia has shown that RA is strongly associated with generalized osteoporosis (Ann. Rheum. Dis. 2003;62:617–23).

Patients were randomized to one of two groups. The first received HRT, which consisted of estradiol and norethisterone acetate, plus a daily dose of 500 mg calcium and 400 IU vitamin D. Controls received only the calcium and vitamin D.

Patients had digital x-ray radiogrammetry–bone mineral density (DXR-BMD) readings at baseline and at 2 years. A total of 13 women had ineligible DXR-BMD readings at baseline because of prostheses, osteosynthetic materials, the position of the hands or insufficient x-ray, wrote the authors. Another 25 patients did not complete the second DXR-BMD 2 years later.

That left a total of 50 women (23 HRT patients, 27 controls) to be included in the study analysis. The mean age of both groups was roughly 58 years, and both groups had a mean disease duration of greater than 10 years.

According to the researchers, at baseline, HT patients and controls had an identical mean DXR-BMD reading of 0.45 g/cm²; HRT patients had a standard deviation of 0.096, vs. 0.081 in the control group.

Two years later, HT patients’ mean reading was identical except for a tiny increase in the standard deviation, to 0.097, whereas control patients’ mean DXR-BMD was 0.44, with a standard deviation of 0.084.

The minute difference was insignificant for the HT group (–0.0015 ± 0.0078), but significant for controls, both in terms of change from baseline and difference from the HT group (–0.18 ± 0.038, P less than .05 for both comparisons).

Put another way, the decrease among HT patients from baseline was 0.36%, while the decrease from baseline for controls was 3.74% – more than 10 times greater.

"DXR-BMD has been proposed to be an outcome measure in monitoring treatments in early RA, and can predict future radiographic joint damage," concluded the authors. "So far, there is limited knowledge of DXR-BMD used as an outcome measure in randomized controlled trials in long-term RA."

Based on the current data, however, "we suggest that DXR-BMD could serve as an outcome measure in [randomized controlled trials] in long-standing RA," they wrote.

"Further studies on disease-modifying drugs are needed to assess its usability."

Dr. Forsblad-d’Elia and Dr. Carlsten said that this study was supported by several grants from rheumatology and other foundations; they added that they had no competing interests to disclose.

Hormone therapy stabilized bone loss over a 2-year period in rheumatoid arthritis patients, as measured on digital x-ray radiogrammetry, according to a study published in Annals of the Rheumatic Diseases.

The study is important not only for finding that hormone therapy (HT) was effective, but because it depended on readings that detected losses of as little as 0.36%.

In contrast, plain radiographs, "the standard method for detection and quantification of joint destruction in RA," cannot detect bone loss of less than 30%, wrote Dr. Helena Forsblad-d’Elia and Dr. Hans Carlsten (Ann. Rheum. Dis. 2010 Nov. 3 [doi: 10.1136/ard.2010.137133]).

Dr. Forsblad-d’Elia and Dr. Carlsten, both of the center for bone and arthritis research at the University of Gothenburg (Sweden), looked at 88 postmenopausal women with radiographic joint destruction due to rheumatoid arthritis. Findings from earlier research by Dr. Forsblad-d’Elia has shown that RA is strongly associated with generalized osteoporosis (Ann. Rheum. Dis. 2003;62:617–23).

Patients were randomized to one of two groups. The first received HRT, which consisted of estradiol and norethisterone acetate, plus a daily dose of 500 mg calcium and 400 IU vitamin D. Controls received only the calcium and vitamin D.

Patients had digital x-ray radiogrammetry–bone mineral density (DXR-BMD) readings at baseline and at 2 years. A total of 13 women had ineligible DXR-BMD readings at baseline because of prostheses, osteosynthetic materials, the position of the hands or insufficient x-ray, wrote the authors. Another 25 patients did not complete the second DXR-BMD 2 years later.

That left a total of 50 women (23 HRT patients, 27 controls) to be included in the study analysis. The mean age of both groups was roughly 58 years, and both groups had a mean disease duration of greater than 10 years.

According to the researchers, at baseline, HT patients and controls had an identical mean DXR-BMD reading of 0.45 g/cm²; HRT patients had a standard deviation of 0.096, vs. 0.081 in the control group.

Two years later, HT patients’ mean reading was identical except for a tiny increase in the standard deviation, to 0.097, whereas control patients’ mean DXR-BMD was 0.44, with a standard deviation of 0.084.

The minute difference was insignificant for the HT group (–0.0015 ± 0.0078), but significant for controls, both in terms of change from baseline and difference from the HT group (–0.18 ± 0.038, P less than .05 for both comparisons).

Put another way, the decrease among HT patients from baseline was 0.36%, while the decrease from baseline for controls was 3.74% – more than 10 times greater.

"DXR-BMD has been proposed to be an outcome measure in monitoring treatments in early RA, and can predict future radiographic joint damage," concluded the authors. "So far, there is limited knowledge of DXR-BMD used as an outcome measure in randomized controlled trials in long-term RA."

Based on the current data, however, "we suggest that DXR-BMD could serve as an outcome measure in [randomized controlled trials] in long-standing RA," they wrote.

"Further studies on disease-modifying drugs are needed to assess its usability."

Dr. Forsblad-d’Elia and Dr. Carlsten said that this study was supported by several grants from rheumatology and other foundations; they added that they had no competing interests to disclose.

Should you use computed tomography or magnetic resonance imaging in the acute stroke setting? There are no easy answers to this question, according to Dr. Todd S. Miller.

Although CT has been the mainstay of acute stroke diagnosis for more than 2 decades, new practice guidelines state that diffusion weighted imaging (DWI) "should be considered more useful than noncontrast CT for the diagnosis of acute ischemic stroke within 12 hours of symptom onset" (Neurology 2010;75:177-85).

Historically, cost, time, and availability have favored CT in the acute stroke setting. MRI offers superior infarct visualization, but it is slower. In the emergency setting, there is pressure to quickly treat patients with cerebral ischemia, while triaging those whose symptoms are explained by alternative diagnoses.

The controversy overlies a background in which only a minority of stroke patients receive any intervention, said Dr. Miller, assistant professor of neuroradiology at Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, N.Y.

"In the acute stroke setting, there’s a significant opportunity to improve outcomes. But as reported as recently as 2009, only 1% of patients (Emerg. Med. Clin. North Am. 2009;27:115-9) who are having a stroke receive thrombolytic therapy," he said in an interview.

"In the United States, stroke is still a major cause of long-term disability, with huge economic and social costs. We want to identify individuals who are having an infarct and try to determine who we can help to improve functional outcomes," he added at the Veith symposium on vascular medicine sponsored by the Cleveland Clinic.

For patients who reach the hospital within 3 hours and for whom hemorrhage and stroke mimics are ruled out via noncontrast CT, the choice of imaging to assess the infarct core to guide treatment usually is based on experience and availability. "Although MRI is clearly more sensitive and specific, quite a few studies have suggested that both CT angiography [CTA] and CT perfusion are adequate. Use whatever is available," he said.

In a comparison of CT perfusion imaging (CTP) and MR DWI in 23 consecutive patients presenting within 12 hours of stroke onset, DWI was more sensitive than was CTP for parenchymal stroke detection, but both modalities were highly accurate predictors of final infarct volume. While DWI tended to underestimate final infarct size, CTP more closely approximated final infarct size (Stroke 2001;32:317).

Other data also suggest that the presence of hyperattenuation on CTP may predict hemorrhage (AJNR Am. J. Neuroradiol. 2007;28:1292-8). Identification of those at risk for hemorrhage allows clinicians to avoid doing harm and causing a worsening of symptoms.

Some clinicians are reluctant to use iodinated contrast for CTA/CTP because of concerns about contrast nephropathy. But in a retrospective study of 224 patients who had received CTA of the brain or neck to evaluate acute stroke syndrome, just 7 (3%) met the criteria for radiocontrast nephropathy, including 2 of 93 (2%) who had emergent CTA without knowledge of their creatinine value. None needed dialysis (Stroke 2007;38:2364-6).

Taken together, the data support CT for evaluating the core infarct and penumbra in stroke patients, as well as for predicting outcome from antithrombotic therapy. MRI allows far better visualization, but it’s hard to get patients into the magnet, it can’t be used in certain patients with metal in their bodies, and it isn’t available in many institutions.

Dr. Miller acknowledged his pro-CT bias, but he said a recent article has caused him to think twice. The study, involving 174 patients with presumed stroke, showed that without significantly increasing door-to-needle time, MRI was feasible in 88% of 161 who required acute imaging and that it supported treat/not treat decisions (Acta. Neurol. Scand. 2009;120:143-9).

"It has not been my experience that MRI and CT take an equal amount of time for the evaluation of acute cerebral ischemia, but if that is the case for you in your center, the evidence clearly favors MRI. Otherwise, CT is king," he said.

Should you use computed tomography or magnetic resonance imaging in the acute stroke setting? There are no easy answers to this question, according to Dr. Todd S. Miller.

Although CT has been the mainstay of acute stroke diagnosis for more than 2 decades, new practice guidelines state that diffusion weighted imaging (DWI) "should be considered more useful than noncontrast CT for the diagnosis of acute ischemic stroke within 12 hours of symptom onset" (Neurology 2010;75:177-85).

Historically, cost, time, and availability have favored CT in the acute stroke setting. MRI offers superior infarct visualization, but it is slower. In the emergency setting, there is pressure to quickly treat patients with cerebral ischemia, while triaging those whose symptoms are explained by alternative diagnoses.

The controversy overlies a background in which only a minority of stroke patients receive any intervention, said Dr. Miller, assistant professor of neuroradiology at Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, N.Y.

"In the acute stroke setting, there’s a significant opportunity to improve outcomes. But as reported as recently as 2009, only 1% of patients (Emerg. Med. Clin. North Am. 2009;27:115-9) who are having a stroke receive thrombolytic therapy," he said in an interview.

"In the United States, stroke is still a major cause of long-term disability, with huge economic and social costs. We want to identify individuals who are having an infarct and try to determine who we can help to improve functional outcomes," he added at the Veith symposium on vascular medicine sponsored by the Cleveland Clinic.

For patients who reach the hospital within 3 hours and for whom hemorrhage and stroke mimics are ruled out via noncontrast CT, the choice of imaging to assess the infarct core to guide treatment usually is based on experience and availability. "Although MRI is clearly more sensitive and specific, quite a few studies have suggested that both CT angiography [CTA] and CT perfusion are adequate. Use whatever is available," he said.

In a comparison of CT perfusion imaging (CTP) and MR DWI in 23 consecutive patients presenting within 12 hours of stroke onset, DWI was more sensitive than was CTP for parenchymal stroke detection, but both modalities were highly accurate predictors of final infarct volume. While DWI tended to underestimate final infarct size, CTP more closely approximated final infarct size (Stroke 2001;32:317).

Other data also suggest that the presence of hyperattenuation on CTP may predict hemorrhage (AJNR Am. J. Neuroradiol. 2007;28:1292-8). Identification of those at risk for hemorrhage allows clinicians to avoid doing harm and causing a worsening of symptoms.

Some clinicians are reluctant to use iodinated contrast for CTA/CTP because of concerns about contrast nephropathy. But in a retrospective study of 224 patients who had received CTA of the brain or neck to evaluate acute stroke syndrome, just 7 (3%) met the criteria for radiocontrast nephropathy, including 2 of 93 (2%) who had emergent CTA without knowledge of their creatinine value. None needed dialysis (Stroke 2007;38:2364-6).

Taken together, the data support CT for evaluating the core infarct and penumbra in stroke patients, as well as for predicting outcome from antithrombotic therapy. MRI allows far better visualization, but it’s hard to get patients into the magnet, it can’t be used in certain patients with metal in their bodies, and it isn’t available in many institutions.

Dr. Miller acknowledged his pro-CT bias, but he said a recent article has caused him to think twice. The study, involving 174 patients with presumed stroke, showed that without significantly increasing door-to-needle time, MRI was feasible in 88% of 161 who required acute imaging and that it supported treat/not treat decisions (Acta. Neurol. Scand. 2009;120:143-9).

"It has not been my experience that MRI and CT take an equal amount of time for the evaluation of acute cerebral ischemia, but if that is the case for you in your center, the evidence clearly favors MRI. Otherwise, CT is king," he said.

Should you use computed tomography or magnetic resonance imaging in the acute stroke setting? There are no easy answers to this question, according to Dr. Todd S. Miller.

Although CT has been the mainstay of acute stroke diagnosis for more than 2 decades, new practice guidelines state that diffusion weighted imaging (DWI) "should be considered more useful than noncontrast CT for the diagnosis of acute ischemic stroke within 12 hours of symptom onset" (Neurology 2010;75:177-85).

Historically, cost, time, and availability have favored CT in the acute stroke setting. MRI offers superior infarct visualization, but it is slower. In the emergency setting, there is pressure to quickly treat patients with cerebral ischemia, while triaging those whose symptoms are explained by alternative diagnoses.

The controversy overlies a background in which only a minority of stroke patients receive any intervention, said Dr. Miller, assistant professor of neuroradiology at Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, N.Y.

"In the acute stroke setting, there’s a significant opportunity to improve outcomes. But as reported as recently as 2009, only 1% of patients (Emerg. Med. Clin. North Am. 2009;27:115-9) who are having a stroke receive thrombolytic therapy," he said in an interview.

"In the United States, stroke is still a major cause of long-term disability, with huge economic and social costs. We want to identify individuals who are having an infarct and try to determine who we can help to improve functional outcomes," he added at the Veith symposium on vascular medicine sponsored by the Cleveland Clinic.

For patients who reach the hospital within 3 hours and for whom hemorrhage and stroke mimics are ruled out via noncontrast CT, the choice of imaging to assess the infarct core to guide treatment usually is based on experience and availability. "Although MRI is clearly more sensitive and specific, quite a few studies have suggested that both CT angiography [CTA] and CT perfusion are adequate. Use whatever is available," he said.

In a comparison of CT perfusion imaging (CTP) and MR DWI in 23 consecutive patients presenting within 12 hours of stroke onset, DWI was more sensitive than was CTP for parenchymal stroke detection, but both modalities were highly accurate predictors of final infarct volume. While DWI tended to underestimate final infarct size, CTP more closely approximated final infarct size (Stroke 2001;32:317).

Other data also suggest that the presence of hyperattenuation on CTP may predict hemorrhage (AJNR Am. J. Neuroradiol. 2007;28:1292-8). Identification of those at risk for hemorrhage allows clinicians to avoid doing harm and causing a worsening of symptoms.

Some clinicians are reluctant to use iodinated contrast for CTA/CTP because of concerns about contrast nephropathy. But in a retrospective study of 224 patients who had received CTA of the brain or neck to evaluate acute stroke syndrome, just 7 (3%) met the criteria for radiocontrast nephropathy, including 2 of 93 (2%) who had emergent CTA without knowledge of their creatinine value. None needed dialysis (Stroke 2007;38:2364-6).

Taken together, the data support CT for evaluating the core infarct and penumbra in stroke patients, as well as for predicting outcome from antithrombotic therapy. MRI allows far better visualization, but it’s hard to get patients into the magnet, it can’t be used in certain patients with metal in their bodies, and it isn’t available in many institutions.

Dr. Miller acknowledged his pro-CT bias, but he said a recent article has caused him to think twice. The study, involving 174 patients with presumed stroke, showed that without significantly increasing door-to-needle time, MRI was feasible in 88% of 161 who required acute imaging and that it supported treat/not treat decisions (Acta. Neurol. Scand. 2009;120:143-9).

"It has not been my experience that MRI and CT take an equal amount of time for the evaluation of acute cerebral ischemia, but if that is the case for you in your center, the evidence clearly favors MRI. Otherwise, CT is king," he said.

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 congress, 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. Through a multiphase process of discussion and voting, the group agreed on a set of nine propositions and two OA definitions based on MRI criteria. (See boxes.) 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, preradiographic 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.”

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.

“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. Tuhina Neogi, a rheumatologist at Boston University, 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.

The Panel's MRI-Based Definition of OA

The two definitions of MRI findings diagnostic of knee OA are:

1. Tibiofemoral OA should have either both features from group A (below), or one feature from group A and at least two from group B. Examination of the patient must also rule out joint trauma in the past 6 months (by history) and inflammatory arthritis (by radiographs, history, and lab 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, anterior femur, or both:

▸ Definite osteophyte formation.

▸ Partial- or full-thickness cartilage loss.

The Panel's Propositions

Here are the nine propositions on MRI diagnosis 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 lab parameters.

3. MRI may be used for inclusion in clinical studies, 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, including cartilage loss; change in cartilage composition; cystic change and development of bone marrow lesions; and ligamentous, tendinous, and meniscal damage.

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 combinations of features.

8. Definite osteophyte production is indicative of OA.

9. Joint space narrowing as assessed by MRI cannot be used as a diagnostic criterion.

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 congress, 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. Through a multiphase process of discussion and voting, the group agreed on a set of nine propositions and two OA definitions based on MRI criteria. (See boxes.) 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, preradiographic 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.”

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.

“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. Tuhina Neogi, a rheumatologist at Boston University, 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.

The Panel's MRI-Based Definition of OA

The two definitions of MRI findings diagnostic of knee OA are:

1. Tibiofemoral OA should have either both features from group A (below), or one feature from group A and at least two from group B. Examination of the patient must also rule out joint trauma in the past 6 months (by history) and inflammatory arthritis (by radiographs, history, and lab 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, anterior femur, or both:

▸ Definite osteophyte formation.

▸ Partial- or full-thickness cartilage loss.

The Panel's Propositions

Here are the nine propositions on MRI diagnosis 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 lab parameters.

3. MRI may be used for inclusion in clinical studies, 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, including cartilage loss; change in cartilage composition; cystic change and development of bone marrow lesions; and ligamentous, tendinous, and meniscal damage.

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 combinations of features.

8. Definite osteophyte production is indicative of OA.

9. Joint space narrowing as assessed by MRI cannot be used as a diagnostic criterion.

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 congress, 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. Through a multiphase process of discussion and voting, the group agreed on a set of nine propositions and two OA definitions based on MRI criteria. (See boxes.) 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, preradiographic 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.”

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.

“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. Tuhina Neogi, a rheumatologist at Boston University, 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.

The Panel's MRI-Based Definition of OA

The two definitions of MRI findings diagnostic of knee OA are:

1. Tibiofemoral OA should have either both features from group A (below), or one feature from group A and at least two from group B. Examination of the patient must also rule out joint trauma in the past 6 months (by history) and inflammatory arthritis (by radiographs, history, and lab 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, anterior femur, or both:

▸ Definite osteophyte formation.

▸ Partial- or full-thickness cartilage loss.

The Panel's Propositions

Here are the nine propositions on MRI diagnosis 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 lab parameters.

3. MRI may be used for inclusion in clinical studies, 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, including cartilage loss; change in cartilage composition; cystic change and development of bone marrow lesions; and ligamentous, tendinous, and meniscal damage.

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 combinations of features.

8. Definite osteophyte production is indicative of OA.

9. Joint space narrowing as assessed by MRI cannot be used as a diagnostic criterion.

SAN FRANCISCO – It’s easy to find someone willing to take your money for a brain scan. It’s a lot harder to use these scans in understanding mental illness, according to Dr. Robert L. Hendren.

“We can’t really find the kind of images that can help us make the diagnosis of a mental disorder,” said Dr. Hendren, director of child and adolescent psychiatry at the University of California, San Francisco. Genetic, metabolic, and other kinds of screening for biomarkers are only slightly more useful, he said at the annual meeting of the American Academy of Pediatrics.

It still makes sense to look for biologic causes for mental illness. “Increasingly, we’re finding that disorders like conduct disorder have a neurological, neurodevelopmental etiology,” Dr. Hendren said. After all, brains grow and change as they interact with the environment.

And physicians need better tools for diagnosing such illnesses. Signs and symptoms don’t always fit neatly into the categories laid out in the Diagnostic and Statistical Manual of Mental Disorders.

So researchers have tried MRI and other approaches to look for patterns that might reveal mental illness. They have found some correlations.

And some imaging centers have leaped on these findings to market their services to families of children with mental illness. “You probably are aware of people doing that,” Dr. Hendren said. “Families will pay $3,000 or $4,000 to have these scans performed and shown to them. And then they get recommendations based on a good history that aren’t much different than if the scans had not been done.”

The problem is that researchers have not traced any common diagnosis to a particular site in the brain. Multiple sites may be involved.

Imaging can help only in very specific instances. Among the accepted indications for MRI include microcephaly, macrocephaly, unusual head shapes, regression, or an abnormal neurologic examination.

Some of the same limitations that apply to MRI apply to other types of tests for biomarkers. Researchers have realized that no single gene is responsible for autism, schizophrenia, or most of the other common mental disorders. “We’ve learned that these are very complex disorders with multiple genes involved,” Dr. Hendren said.

But when there is reason to believe genes are involved, genetic testing might be in order. For example, he said some experts recommend a comparative genomic hybridization array for various intellectual disabilities, developmental disorders, and autism. Autistic children also might benefit from further genetic tests, including a test for fragile X, since about 3% have this genetic condition.

Other authorities have recommended a chromosomal microarray for patients with developmental delay, intellectual disabilities, autism spectrum disorder, or multiple congenital anomalies. For patients with clear chromosomal rearrangements – or a family history of these rearrangements, or multiple miscarriages, G-banded karyotyping might be in order, Dr. Hendren said.

Metabolic screening also can yield some information about mental disorders, but is really worthwhile only in patients with clear signs of metabolic disorder, such as a history of lethargy, cyclic vomiting, early seizures, dysmorphisms, mental retardation, or regression. And if these tests are a part of newborn screening – as they often are – there’s no need to repeat them, he said.

Some authorities also recommend a complete blood count for mental disorders. Naturally, other tests, such as thyroid function, serum organic and amino acids, serum lactate and pyruvate, lead screening, iron deficiency, methyl CpG binding protein 2, and Wood’s lamp, might prove helpful when specific conditions are expected,. Most other tests are more controversial.

So while waiting for researchers to find a high-tech solution for diagnosing mental illness, what can physicians do to identify mental illness in their patients? “Evaluation should be guided by in-depth history and family history, and a good physical examination,” Dr. Hendren said.

He said he has received funding for clinical trials from Forest Laboratories, BioMarin, Curemark, the National Institute of Mental Health, and Autism Speaks.

SAN FRANCISCO – It’s easy to find someone willing to take your money for a brain scan. It’s a lot harder to use these scans in understanding mental illness, according to Dr. Robert L. Hendren.

“We can’t really find the kind of images that can help us make the diagnosis of a mental disorder,” said Dr. Hendren, director of child and adolescent psychiatry at the University of California, San Francisco. Genetic, metabolic, and other kinds of screening for biomarkers are only slightly more useful, he said at the annual meeting of the American Academy of Pediatrics.

It still makes sense to look for biologic causes for mental illness. “Increasingly, we’re finding that disorders like conduct disorder have a neurological, neurodevelopmental etiology,” Dr. Hendren said. After all, brains grow and change as they interact with the environment.

And physicians need better tools for diagnosing such illnesses. Signs and symptoms don’t always fit neatly into the categories laid out in the Diagnostic and Statistical Manual of Mental Disorders.

So researchers have tried MRI and other approaches to look for patterns that might reveal mental illness. They have found some correlations.

And some imaging centers have leaped on these findings to market their services to families of children with mental illness. “You probably are aware of people doing that,” Dr. Hendren said. “Families will pay $3,000 or $4,000 to have these scans performed and shown to them. And then they get recommendations based on a good history that aren’t much different than if the scans had not been done.”

The problem is that researchers have not traced any common diagnosis to a particular site in the brain. Multiple sites may be involved.

Imaging can help only in very specific instances. Among the accepted indications for MRI include microcephaly, macrocephaly, unusual head shapes, regression, or an abnormal neurologic examination.

Some of the same limitations that apply to MRI apply to other types of tests for biomarkers. Researchers have realized that no single gene is responsible for autism, schizophrenia, or most of the other common mental disorders. “We’ve learned that these are very complex disorders with multiple genes involved,” Dr. Hendren said.

But when there is reason to believe genes are involved, genetic testing might be in order. For example, he said some experts recommend a comparative genomic hybridization array for various intellectual disabilities, developmental disorders, and autism. Autistic children also might benefit from further genetic tests, including a test for fragile X, since about 3% have this genetic condition.

Other authorities have recommended a chromosomal microarray for patients with developmental delay, intellectual disabilities, autism spectrum disorder, or multiple congenital anomalies. For patients with clear chromosomal rearrangements – or a family history of these rearrangements, or multiple miscarriages, G-banded karyotyping might be in order, Dr. Hendren said.

Metabolic screening also can yield some information about mental disorders, but is really worthwhile only in patients with clear signs of metabolic disorder, such as a history of lethargy, cyclic vomiting, early seizures, dysmorphisms, mental retardation, or regression. And if these tests are a part of newborn screening – as they often are – there’s no need to repeat them, he said.

Some authorities also recommend a complete blood count for mental disorders. Naturally, other tests, such as thyroid function, serum organic and amino acids, serum lactate and pyruvate, lead screening, iron deficiency, methyl CpG binding protein 2, and Wood’s lamp, might prove helpful when specific conditions are expected,. Most other tests are more controversial.

So while waiting for researchers to find a high-tech solution for diagnosing mental illness, what can physicians do to identify mental illness in their patients? “Evaluation should be guided by in-depth history and family history, and a good physical examination,” Dr. Hendren said.

He said he has received funding for clinical trials from Forest Laboratories, BioMarin, Curemark, the National Institute of Mental Health, and Autism Speaks.

SAN FRANCISCO – It’s easy to find someone willing to take your money for a brain scan. It’s a lot harder to use these scans in understanding mental illness, according to Dr. Robert L. Hendren.

“We can’t really find the kind of images that can help us make the diagnosis of a mental disorder,” said Dr. Hendren, director of child and adolescent psychiatry at the University of California, San Francisco. Genetic, metabolic, and other kinds of screening for biomarkers are only slightly more useful, he said at the annual meeting of the American Academy of Pediatrics.

It still makes sense to look for biologic causes for mental illness. “Increasingly, we’re finding that disorders like conduct disorder have a neurological, neurodevelopmental etiology,” Dr. Hendren said. After all, brains grow and change as they interact with the environment.

And physicians need better tools for diagnosing such illnesses. Signs and symptoms don’t always fit neatly into the categories laid out in the Diagnostic and Statistical Manual of Mental Disorders.

So researchers have tried MRI and other approaches to look for patterns that might reveal mental illness. They have found some correlations.

And some imaging centers have leaped on these findings to market their services to families of children with mental illness. “You probably are aware of people doing that,” Dr. Hendren said. “Families will pay $3,000 or $4,000 to have these scans performed and shown to them. And then they get recommendations based on a good history that aren’t much different than if the scans had not been done.”

The problem is that researchers have not traced any common diagnosis to a particular site in the brain. Multiple sites may be involved.

Imaging can help only in very specific instances. Among the accepted indications for MRI include microcephaly, macrocephaly, unusual head shapes, regression, or an abnormal neurologic examination.

Some of the same limitations that apply to MRI apply to other types of tests for biomarkers. Researchers have realized that no single gene is responsible for autism, schizophrenia, or most of the other common mental disorders. “We’ve learned that these are very complex disorders with multiple genes involved,” Dr. Hendren said.

But when there is reason to believe genes are involved, genetic testing might be in order. For example, he said some experts recommend a comparative genomic hybridization array for various intellectual disabilities, developmental disorders, and autism. Autistic children also might benefit from further genetic tests, including a test for fragile X, since about 3% have this genetic condition.

Other authorities have recommended a chromosomal microarray for patients with developmental delay, intellectual disabilities, autism spectrum disorder, or multiple congenital anomalies. For patients with clear chromosomal rearrangements – or a family history of these rearrangements, or multiple miscarriages, G-banded karyotyping might be in order, Dr. Hendren said.

Metabolic screening also can yield some information about mental disorders, but is really worthwhile only in patients with clear signs of metabolic disorder, such as a history of lethargy, cyclic vomiting, early seizures, dysmorphisms, mental retardation, or regression. And if these tests are a part of newborn screening – as they often are – there’s no need to repeat them, he said.

Some authorities also recommend a complete blood count for mental disorders. Naturally, other tests, such as thyroid function, serum organic and amino acids, serum lactate and pyruvate, lead screening, iron deficiency, methyl CpG binding protein 2, and Wood’s lamp, might prove helpful when specific conditions are expected,. Most other tests are more controversial.

So while waiting for researchers to find a high-tech solution for diagnosing mental illness, what can physicians do to identify mental illness in their patients? “Evaluation should be guided by in-depth history and family history, and a good physical examination,” Dr. Hendren said.

He said he has received funding for clinical trials from Forest Laboratories, BioMarin, Curemark, the National Institute of Mental Health, and Autism Speaks.

SAN DIEGO – Magnetic resonance imaging identified additional breast cancer in 11% of women with newly diagnosed disease who were otherwise eligible for partial breast irradiation, preliminary results from an ongoing study demonstrated.

Treatment of these patients with limited radiation fields would result in undertreatment of the tumor and could potentially compromise disease control, Dr. Paige L. Dorn said at the annual meeting of the American Society for Radiation Oncology.

Treatment for early-stage breast cancer with partial breast irradiation is currently under investigation in a multi-institutional, randomized controlled trial, NSABP B-39. Retrospective data from the University of Chicago Hospitals and Clinics and other institutions "have shown that MRI is able to find additional disease in 5%-10% of otherwise partial breast irradiation–eligible candidates, based on mammogram and ultrasound alone," said Dr. Dorn of the university’s department of radiation oncology. "The purpose of this study is to evaluate the utility of MRI in detecting clinically occult foci of disease in a prospectively identified cohort of partial breast irradiation candidates uniformly undergoing MRI in addition to mammogram and ultrasound."

Since June of 2009, all imaging and surgical pathology have been reviewed in a multidisciplinary setting by radiologists, surgeons, pathologists, and radiation oncologists at the university to determine candidacy for partial breast irradiation. In patients eligible for partial breast irradiation, Dr. Dorn and her associates prospectively documented whether MRI identified additional lesions in the same quadrant (multifocal), a different quadrant (multicentric), or the contralateral breast. They biopsied suspicious MRI findings to confirm pathology and then prospectively recorded whether MRI findings prompted a change in the eligibility for partial breast irradiation according to the entry criteria outlined in NSABP B-39. Prospectively collected data was verified by retrospective evaluation of all patient records.

Of 486 patients screened by the researchers between June 2009 and October 2010, Dr. Dorn reported that 91 (18.7%) were deemed eligible for partial breast irradiation based on mammogram, ultrasound, and pathology alone. Their median age was 56 years.

Of the 91 patients, 66 had invasive ductal or lobular carcinoma, 18 patients had ductal carcinoma in situ, and 7 had invasive lobular disease. MRI identified additional disease in 10 patients. Multifocal disease was seen in 9 of these patients, while contralateral disease was confirmed in 1.

The researchers also found that MRI was more likely to identify occult disease in patients younger than age 50, in those who were premenopausal, and in those who had tumor sizes of 2 cm or greater.

Dr. Dorn said the study had certain limitations, including the fact that the potential impact of MRI on disease outcomes after partial breast irradiation remains unknown. "Whether these multifocal lesions would have been surgically excised is unknown," she added.

Based on the results of this and other studies, she concluded that MRI "should be increasingly considered as part of the work-up for partial breast irradiation candidates. MRI may help refine criteria for patient selection, especially in those with higher-risk features. We plan to continue this prospective study to further define the role of MRI in this population."

Dr. Dorn said she had no relevant financial conflicts.

SAN DIEGO – Magnetic resonance imaging identified additional breast cancer in 11% of women with newly diagnosed disease who were otherwise eligible for partial breast irradiation, preliminary results from an ongoing study demonstrated.

Treatment of these patients with limited radiation fields would result in undertreatment of the tumor and could potentially compromise disease control, Dr. Paige L. Dorn said at the annual meeting of the American Society for Radiation Oncology.

Treatment for early-stage breast cancer with partial breast irradiation is currently under investigation in a multi-institutional, randomized controlled trial, NSABP B-39. Retrospective data from the University of Chicago Hospitals and Clinics and other institutions "have shown that MRI is able to find additional disease in 5%-10% of otherwise partial breast irradiation–eligible candidates, based on mammogram and ultrasound alone," said Dr. Dorn of the university’s department of radiation oncology. "The purpose of this study is to evaluate the utility of MRI in detecting clinically occult foci of disease in a prospectively identified cohort of partial breast irradiation candidates uniformly undergoing MRI in addition to mammogram and ultrasound."

Since June of 2009, all imaging and surgical pathology have been reviewed in a multidisciplinary setting by radiologists, surgeons, pathologists, and radiation oncologists at the university to determine candidacy for partial breast irradiation. In patients eligible for partial breast irradiation, Dr. Dorn and her associates prospectively documented whether MRI identified additional lesions in the same quadrant (multifocal), a different quadrant (multicentric), or the contralateral breast. They biopsied suspicious MRI findings to confirm pathology and then prospectively recorded whether MRI findings prompted a change in the eligibility for partial breast irradiation according to the entry criteria outlined in NSABP B-39. Prospectively collected data was verified by retrospective evaluation of all patient records.

Of 486 patients screened by the researchers between June 2009 and October 2010, Dr. Dorn reported that 91 (18.7%) were deemed eligible for partial breast irradiation based on mammogram, ultrasound, and pathology alone. Their median age was 56 years.

Of the 91 patients, 66 had invasive ductal or lobular carcinoma, 18 patients had ductal carcinoma in situ, and 7 had invasive lobular disease. MRI identified additional disease in 10 patients. Multifocal disease was seen in 9 of these patients, while contralateral disease was confirmed in 1.

The researchers also found that MRI was more likely to identify occult disease in patients younger than age 50, in those who were premenopausal, and in those who had tumor sizes of 2 cm or greater.

Dr. Dorn said the study had certain limitations, including the fact that the potential impact of MRI on disease outcomes after partial breast irradiation remains unknown. "Whether these multifocal lesions would have been surgically excised is unknown," she added.

Based on the results of this and other studies, she concluded that MRI "should be increasingly considered as part of the work-up for partial breast irradiation candidates. MRI may help refine criteria for patient selection, especially in those with higher-risk features. We plan to continue this prospective study to further define the role of MRI in this population."

Dr. Dorn said she had no relevant financial conflicts.

SAN DIEGO – Magnetic resonance imaging identified additional breast cancer in 11% of women with newly diagnosed disease who were otherwise eligible for partial breast irradiation, preliminary results from an ongoing study demonstrated.

Treatment of these patients with limited radiation fields would result in undertreatment of the tumor and could potentially compromise disease control, Dr. Paige L. Dorn said at the annual meeting of the American Society for Radiation Oncology.

Treatment for early-stage breast cancer with partial breast irradiation is currently under investigation in a multi-institutional, randomized controlled trial, NSABP B-39. Retrospective data from the University of Chicago Hospitals and Clinics and other institutions "have shown that MRI is able to find additional disease in 5%-10% of otherwise partial breast irradiation–eligible candidates, based on mammogram and ultrasound alone," said Dr. Dorn of the university’s department of radiation oncology. "The purpose of this study is to evaluate the utility of MRI in detecting clinically occult foci of disease in a prospectively identified cohort of partial breast irradiation candidates uniformly undergoing MRI in addition to mammogram and ultrasound."

Since June of 2009, all imaging and surgical pathology have been reviewed in a multidisciplinary setting by radiologists, surgeons, pathologists, and radiation oncologists at the university to determine candidacy for partial breast irradiation. In patients eligible for partial breast irradiation, Dr. Dorn and her associates prospectively documented whether MRI identified additional lesions in the same quadrant (multifocal), a different quadrant (multicentric), or the contralateral breast. They biopsied suspicious MRI findings to confirm pathology and then prospectively recorded whether MRI findings prompted a change in the eligibility for partial breast irradiation according to the entry criteria outlined in NSABP B-39. Prospectively collected data was verified by retrospective evaluation of all patient records.

Of 486 patients screened by the researchers between June 2009 and October 2010, Dr. Dorn reported that 91 (18.7%) were deemed eligible for partial breast irradiation based on mammogram, ultrasound, and pathology alone. Their median age was 56 years.

Of the 91 patients, 66 had invasive ductal or lobular carcinoma, 18 patients had ductal carcinoma in situ, and 7 had invasive lobular disease. MRI identified additional disease in 10 patients. Multifocal disease was seen in 9 of these patients, while contralateral disease was confirmed in 1.

The researchers also found that MRI was more likely to identify occult disease in patients younger than age 50, in those who were premenopausal, and in those who had tumor sizes of 2 cm or greater.

Dr. Dorn said the study had certain limitations, including the fact that the potential impact of MRI on disease outcomes after partial breast irradiation remains unknown. "Whether these multifocal lesions would have been surgically excised is unknown," she added.

Based on the results of this and other studies, she concluded that MRI "should be increasingly considered as part of the work-up for partial breast irradiation candidates. MRI may help refine criteria for patient selection, especially in those with higher-risk features. We plan to continue this prospective study to further define the role of MRI in this population."

Dr. Dorn said she had no relevant financial conflicts.

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