Imaging

Doppler myocardial imaging to assess systolic activation delay can help determine whether a condition is hypertrophic cardiomyopathy or merely the result of athletic training—and help predict serious adverse cardiac events, Italian researchers reported.

Dr. Antonello D'Andrea of the Second University of Naples (Italy) and colleagues followed 70 patients with hypertrophic cardiomyopathy (HCM) and 85 age- and sex-matched competitive athletes with enlarged left ventricles and interventricular septa thicker than 12 mm (Br. J. Sports Med. 2006;40:244–50).

During the 4-year follow-up, the study's primary end point was cardiovascular mortality. Eight HCM patients died during follow-up; none of the athletes had a cardiovascular event. The participants were aged 29 years on average and were matched for blood pressure. Eighty percent of them were male. All had standard pulsed Doppler echocardiography and pulsed Doppler myocardial imaging in six myocardial segments. HCM patients showed a “significant global Doppler interventricular delay,” the authors said. One-fifth of the HCM patients had a relative who had died from an HCM-related cardiac event.

Doppler myocardial imaging to assess systolic activation delay can help determine whether a condition is hypertrophic cardiomyopathy or merely the result of athletic training—and help predict serious adverse cardiac events, Italian researchers reported.

Dr. Antonello D'Andrea of the Second University of Naples (Italy) and colleagues followed 70 patients with hypertrophic cardiomyopathy (HCM) and 85 age- and sex-matched competitive athletes with enlarged left ventricles and interventricular septa thicker than 12 mm (Br. J. Sports Med. 2006;40:244–50).

During the 4-year follow-up, the study's primary end point was cardiovascular mortality. Eight HCM patients died during follow-up; none of the athletes had a cardiovascular event. The participants were aged 29 years on average and were matched for blood pressure. Eighty percent of them were male. All had standard pulsed Doppler echocardiography and pulsed Doppler myocardial imaging in six myocardial segments. HCM patients showed a “significant global Doppler interventricular delay,” the authors said. One-fifth of the HCM patients had a relative who had died from an HCM-related cardiac event.

Doppler myocardial imaging to assess systolic activation delay can help determine whether a condition is hypertrophic cardiomyopathy or merely the result of athletic training—and help predict serious adverse cardiac events, Italian researchers reported.

Dr. Antonello D'Andrea of the Second University of Naples (Italy) and colleagues followed 70 patients with hypertrophic cardiomyopathy (HCM) and 85 age- and sex-matched competitive athletes with enlarged left ventricles and interventricular septa thicker than 12 mm (Br. J. Sports Med. 2006;40:244–50).

During the 4-year follow-up, the study's primary end point was cardiovascular mortality. Eight HCM patients died during follow-up; none of the athletes had a cardiovascular event. The participants were aged 29 years on average and were matched for blood pressure. Eighty percent of them were male. All had standard pulsed Doppler echocardiography and pulsed Doppler myocardial imaging in six myocardial segments. HCM patients showed a “significant global Doppler interventricular delay,” the authors said. One-fifth of the HCM patients had a relative who had died from an HCM-related cardiac event.

SCOTTSDALE, ARIZ. — With many more infants surviving congenital heart disease, pediatric cardiologists have a new challenge, Dr. Alan H. Friedman told physicians at a pediatric update sponsored by Phoenix Children's Hospital.

Many more survivors must be followed through adolescence and into adulthood with noninvasive cardiac monitoring, said Dr. Friedman, director of pediatric cardiovascular imaging services at Yale-New Haven (Conn.) Children's Hospital, and of Yale University, New Haven.

Four-dimensional magnetic resonance imaging is “where the future of cardiology is going to be,” he predicted. It is safer than methods that expose them to radiation, and it has the potential to provide more graphic information than can be obtained with any other technology.

“The future will be to take three-dimensional imaging in time and rotate it so we can provide to our surgeons the most graphic information,” he said.

In the meantime, new and better tools have already expanded the physician's ability to image the heart and other structures within small pediatric patients.

“This is not a competition between these different imaging technologies, but rather that they complement each other,” he said, comparing the options.

The chest x-ray remains a part of everyday practice, he said, praising its accuracy in depicting the relationship between the heart and lungs: in particular, cardiac size, pulmonary blood flow, and pulmonary edema. Radiation exposure is minimal with chest x-rays, he continued. But they are not specific enough to assess certain forms of congenital heart disease (CHD).

Dr. Friedman described ultrasound as the workhorse of pediatric cardiology. Transthoracic echocardiography is safe and portable with the use of laptops that can be brought directly to the bedside.

Echocardiography allows physicians to take a disciplined, segmental approach to imaging the heart, he continued. After determining whether the heart is in the correct position, they can assess systemic venous drainage, pulmonary venous drainage, atrioventricular connections, ventriculoarterial connections, and intra- and extracardiac structures.

Ultrasound is useful for assessing virtually every type of congenital heart defect, including ventricular septal defects, the most common form of CHD, according to Dr. Friedman. Physicians can confirm the clinical diagnosis and see the defect's location in the ventricular septum. They can measure size, flow, and pressure across the defect. Small probes enable the use of transesophageal echocardiography (TEE) in children of all ages. Dr. Friedman said TEE provides excellent anatomic definition because lungs, bone, and muscle do not interfere with the imaging.

“We are looking right at the back of the heart from the esophagus. There is nothing in between,” he said.

Dr. Friedman recommended TEE for assessing very small, hard-to-see abnormalities. “If endocarditis is suspected, transesophageal electrocardiogram might be the way to go.”

It is also useful, he added, for the Fontan patient and others who require surgery. Whereas thoracic echo is not practical in the operating room, he said a probe in the esophagus can provide information during surgery and assess the adequacy of repair for better postoperative management.

TEE is also useful in the cath lab, he continued. It helps define pathophysiology and is an alternative to imaging methods that expose the patient to radiation.

With three-dimensional echocardiography, he said, physicians can obtain beautiful, real-time pictures of the atrial septum, mitral valve, and aortic valve structure.

Three advances—radionuclide imaging, positron emission tomography, and computed tomography—are increasingly used, but Dr. Friedman urged caution because they expose children to ionizing radiation.

Radionuclide imaging allows accurate measurement of right and left ventricular function. Unlike echocardiography, its results are not subject to variable interobserver interpretation. He recommended PET scanning for assessing myocardial metabolism, perfusion, and viability.

Dr. Friedman said ultrafast CT scanning produces very-high-resolution images that can provide excellent information on blood flow and cardiac function. It also can assess areas of stenosis, particularly in the distal pulmonary artery, that are missed by echocardiography.

Although not yet portable, MRI and MR angiography also offer excellent resolution, according to Dr. Friedman, but without the high doses of radiation with CT scanning. Three-dimensional images are already available for surgical planning, he said, and MR cardiac catheterization laboratories are being developed.

'This is not a competition between these different imaging technologies … they complement each other.' DR. FRIEDMAN

A CT scan with three-dimensional reconstruction shows a stent placed in this patient to aortic coarctation. With three-dimensional echocardiography, physicians can obtain real-time images of the atrial septum, mitral valve, and aortic valve structure.

A transesophageal echocardiogram shows a secundum atrial septal defect (ASD) in a toddler. This technology provides excellent anatomic definition because lungs, bone, and muscle do not interfere with the imaging (LA, left atrium; RA, right atrium; RV, right ventricle). Photos courtesy Dr. Alan Friedman

SCOTTSDALE, ARIZ. — With many more infants surviving congenital heart disease, pediatric cardiologists have a new challenge, Dr. Alan H. Friedman told physicians at a pediatric update sponsored by Phoenix Children's Hospital.

Many more survivors must be followed through adolescence and into adulthood with noninvasive cardiac monitoring, said Dr. Friedman, director of pediatric cardiovascular imaging services at Yale-New Haven (Conn.) Children's Hospital, and of Yale University, New Haven.

Four-dimensional magnetic resonance imaging is “where the future of cardiology is going to be,” he predicted. It is safer than methods that expose them to radiation, and it has the potential to provide more graphic information than can be obtained with any other technology.

“The future will be to take three-dimensional imaging in time and rotate it so we can provide to our surgeons the most graphic information,” he said.

In the meantime, new and better tools have already expanded the physician's ability to image the heart and other structures within small pediatric patients.

“This is not a competition between these different imaging technologies, but rather that they complement each other,” he said, comparing the options.

The chest x-ray remains a part of everyday practice, he said, praising its accuracy in depicting the relationship between the heart and lungs: in particular, cardiac size, pulmonary blood flow, and pulmonary edema. Radiation exposure is minimal with chest x-rays, he continued. But they are not specific enough to assess certain forms of congenital heart disease (CHD).

Dr. Friedman described ultrasound as the workhorse of pediatric cardiology. Transthoracic echocardiography is safe and portable with the use of laptops that can be brought directly to the bedside.

Echocardiography allows physicians to take a disciplined, segmental approach to imaging the heart, he continued. After determining whether the heart is in the correct position, they can assess systemic venous drainage, pulmonary venous drainage, atrioventricular connections, ventriculoarterial connections, and intra- and extracardiac structures.

Ultrasound is useful for assessing virtually every type of congenital heart defect, including ventricular septal defects, the most common form of CHD, according to Dr. Friedman. Physicians can confirm the clinical diagnosis and see the defect's location in the ventricular septum. They can measure size, flow, and pressure across the defect. Small probes enable the use of transesophageal echocardiography (TEE) in children of all ages. Dr. Friedman said TEE provides excellent anatomic definition because lungs, bone, and muscle do not interfere with the imaging.

“We are looking right at the back of the heart from the esophagus. There is nothing in between,” he said.

Dr. Friedman recommended TEE for assessing very small, hard-to-see abnormalities. “If endocarditis is suspected, transesophageal electrocardiogram might be the way to go.”

It is also useful, he added, for the Fontan patient and others who require surgery. Whereas thoracic echo is not practical in the operating room, he said a probe in the esophagus can provide information during surgery and assess the adequacy of repair for better postoperative management.

TEE is also useful in the cath lab, he continued. It helps define pathophysiology and is an alternative to imaging methods that expose the patient to radiation.

With three-dimensional echocardiography, he said, physicians can obtain beautiful, real-time pictures of the atrial septum, mitral valve, and aortic valve structure.

Three advances—radionuclide imaging, positron emission tomography, and computed tomography—are increasingly used, but Dr. Friedman urged caution because they expose children to ionizing radiation.

Radionuclide imaging allows accurate measurement of right and left ventricular function. Unlike echocardiography, its results are not subject to variable interobserver interpretation. He recommended PET scanning for assessing myocardial metabolism, perfusion, and viability.

Dr. Friedman said ultrafast CT scanning produces very-high-resolution images that can provide excellent information on blood flow and cardiac function. It also can assess areas of stenosis, particularly in the distal pulmonary artery, that are missed by echocardiography.

Although not yet portable, MRI and MR angiography also offer excellent resolution, according to Dr. Friedman, but without the high doses of radiation with CT scanning. Three-dimensional images are already available for surgical planning, he said, and MR cardiac catheterization laboratories are being developed.

'This is not a competition between these different imaging technologies … they complement each other.' DR. FRIEDMAN

A CT scan with three-dimensional reconstruction shows a stent placed in this patient to aortic coarctation. With three-dimensional echocardiography, physicians can obtain real-time images of the atrial septum, mitral valve, and aortic valve structure.

A transesophageal echocardiogram shows a secundum atrial septal defect (ASD) in a toddler. This technology provides excellent anatomic definition because lungs, bone, and muscle do not interfere with the imaging (LA, left atrium; RA, right atrium; RV, right ventricle). Photos courtesy Dr. Alan Friedman

SCOTTSDALE, ARIZ. — With many more infants surviving congenital heart disease, pediatric cardiologists have a new challenge, Dr. Alan H. Friedman told physicians at a pediatric update sponsored by Phoenix Children's Hospital.

Many more survivors must be followed through adolescence and into adulthood with noninvasive cardiac monitoring, said Dr. Friedman, director of pediatric cardiovascular imaging services at Yale-New Haven (Conn.) Children's Hospital, and of Yale University, New Haven.

Four-dimensional magnetic resonance imaging is “where the future of cardiology is going to be,” he predicted. It is safer than methods that expose them to radiation, and it has the potential to provide more graphic information than can be obtained with any other technology.

“The future will be to take three-dimensional imaging in time and rotate it so we can provide to our surgeons the most graphic information,” he said.

In the meantime, new and better tools have already expanded the physician's ability to image the heart and other structures within small pediatric patients.

“This is not a competition between these different imaging technologies, but rather that they complement each other,” he said, comparing the options.

The chest x-ray remains a part of everyday practice, he said, praising its accuracy in depicting the relationship between the heart and lungs: in particular, cardiac size, pulmonary blood flow, and pulmonary edema. Radiation exposure is minimal with chest x-rays, he continued. But they are not specific enough to assess certain forms of congenital heart disease (CHD).

Dr. Friedman described ultrasound as the workhorse of pediatric cardiology. Transthoracic echocardiography is safe and portable with the use of laptops that can be brought directly to the bedside.

Echocardiography allows physicians to take a disciplined, segmental approach to imaging the heart, he continued. After determining whether the heart is in the correct position, they can assess systemic venous drainage, pulmonary venous drainage, atrioventricular connections, ventriculoarterial connections, and intra- and extracardiac structures.

Ultrasound is useful for assessing virtually every type of congenital heart defect, including ventricular septal defects, the most common form of CHD, according to Dr. Friedman. Physicians can confirm the clinical diagnosis and see the defect's location in the ventricular septum. They can measure size, flow, and pressure across the defect. Small probes enable the use of transesophageal echocardiography (TEE) in children of all ages. Dr. Friedman said TEE provides excellent anatomic definition because lungs, bone, and muscle do not interfere with the imaging.

“We are looking right at the back of the heart from the esophagus. There is nothing in between,” he said.

Dr. Friedman recommended TEE for assessing very small, hard-to-see abnormalities. “If endocarditis is suspected, transesophageal electrocardiogram might be the way to go.”

It is also useful, he added, for the Fontan patient and others who require surgery. Whereas thoracic echo is not practical in the operating room, he said a probe in the esophagus can provide information during surgery and assess the adequacy of repair for better postoperative management.

TEE is also useful in the cath lab, he continued. It helps define pathophysiology and is an alternative to imaging methods that expose the patient to radiation.

With three-dimensional echocardiography, he said, physicians can obtain beautiful, real-time pictures of the atrial septum, mitral valve, and aortic valve structure.

Three advances—radionuclide imaging, positron emission tomography, and computed tomography—are increasingly used, but Dr. Friedman urged caution because they expose children to ionizing radiation.

Radionuclide imaging allows accurate measurement of right and left ventricular function. Unlike echocardiography, its results are not subject to variable interobserver interpretation. He recommended PET scanning for assessing myocardial metabolism, perfusion, and viability.

Dr. Friedman said ultrafast CT scanning produces very-high-resolution images that can provide excellent information on blood flow and cardiac function. It also can assess areas of stenosis, particularly in the distal pulmonary artery, that are missed by echocardiography.

Although not yet portable, MRI and MR angiography also offer excellent resolution, according to Dr. Friedman, but without the high doses of radiation with CT scanning. Three-dimensional images are already available for surgical planning, he said, and MR cardiac catheterization laboratories are being developed.

'This is not a competition between these different imaging technologies … they complement each other.' DR. FRIEDMAN

A CT scan with three-dimensional reconstruction shows a stent placed in this patient to aortic coarctation. With three-dimensional echocardiography, physicians can obtain real-time images of the atrial septum, mitral valve, and aortic valve structure.

A transesophageal echocardiogram shows a secundum atrial septal defect (ASD) in a toddler. This technology provides excellent anatomic definition because lungs, bone, and muscle do not interfere with the imaging (LA, left atrium; RA, right atrium; RV, right ventricle). Photos courtesy Dr. Alan Friedman

SAN FRANCISCO — Looks can be deceiving when evaluating stenoses for treatment with stenting, Dr. John M. Hodgson said at a cardiovascular imaging conference sponsored by the American College of Cardiology.

Not all stenoses detected on angiography are accompanied by ischemia, said Dr. Hodgson of St. Joseph's Hospital, Phoenix. “Two-thirds of the time, when a patient comes to the cath lab we do not have any functional imaging,” he said. “We do not know for sure that the patient has ischemia. And then we're left to interpret these fuzzy, two-dimensional angiograms.”

But the relatively new technology of measuring fractional flow reserve (FFR) during catheterization could help physicians make better informed decisions about revascularization and stenting.

In FFR, a pressure transducer is sent into the coronary artery, past the anatomic lesion. FFR is the transstenotic pressure gradient across a stenosis, measured at peak blood flow after the administration of a vasodilator (such as adenosine) and indexed for aortic driving pressure.

The result is a direct measurement of the influence of a specific lesion on blood flow. Only when the FFR is 0.75 or less, indicating a functional blockage of at least 25%, is stenting helpful.

The value of FFR was shown in a prospective randomized trial that indicated that not only is it safe to not revascularize stable lesions that don't limit blood flow more than 25%, but also that it provides better 24-month outcomes than does angiography (Circulation 2001;103:2928–34).

SAN FRANCISCO — Looks can be deceiving when evaluating stenoses for treatment with stenting, Dr. John M. Hodgson said at a cardiovascular imaging conference sponsored by the American College of Cardiology.

Not all stenoses detected on angiography are accompanied by ischemia, said Dr. Hodgson of St. Joseph's Hospital, Phoenix. “Two-thirds of the time, when a patient comes to the cath lab we do not have any functional imaging,” he said. “We do not know for sure that the patient has ischemia. And then we're left to interpret these fuzzy, two-dimensional angiograms.”

But the relatively new technology of measuring fractional flow reserve (FFR) during catheterization could help physicians make better informed decisions about revascularization and stenting.

In FFR, a pressure transducer is sent into the coronary artery, past the anatomic lesion. FFR is the transstenotic pressure gradient across a stenosis, measured at peak blood flow after the administration of a vasodilator (such as adenosine) and indexed for aortic driving pressure.

The result is a direct measurement of the influence of a specific lesion on blood flow. Only when the FFR is 0.75 or less, indicating a functional blockage of at least 25%, is stenting helpful.

The value of FFR was shown in a prospective randomized trial that indicated that not only is it safe to not revascularize stable lesions that don't limit blood flow more than 25%, but also that it provides better 24-month outcomes than does angiography (Circulation 2001;103:2928–34).

SAN FRANCISCO — Looks can be deceiving when evaluating stenoses for treatment with stenting, Dr. John M. Hodgson said at a cardiovascular imaging conference sponsored by the American College of Cardiology.

Not all stenoses detected on angiography are accompanied by ischemia, said Dr. Hodgson of St. Joseph's Hospital, Phoenix. “Two-thirds of the time, when a patient comes to the cath lab we do not have any functional imaging,” he said. “We do not know for sure that the patient has ischemia. And then we're left to interpret these fuzzy, two-dimensional angiograms.”

But the relatively new technology of measuring fractional flow reserve (FFR) during catheterization could help physicians make better informed decisions about revascularization and stenting.

In FFR, a pressure transducer is sent into the coronary artery, past the anatomic lesion. FFR is the transstenotic pressure gradient across a stenosis, measured at peak blood flow after the administration of a vasodilator (such as adenosine) and indexed for aortic driving pressure.

The result is a direct measurement of the influence of a specific lesion on blood flow. Only when the FFR is 0.75 or less, indicating a functional blockage of at least 25%, is stenting helpful.

The value of FFR was shown in a prospective randomized trial that indicated that not only is it safe to not revascularize stable lesions that don't limit blood flow more than 25%, but also that it provides better 24-month outcomes than does angiography (Circulation 2001;103:2928–34).

PHILADELPHIA — Giving N-acetylcysteine as an adjunctive agent may reduce the risk of acute renal injury following contrast imaging procedures in high-risk patients, Dr. Venkatesh Jayaraman reported at the annual meeting of the American Society of Nephrology.

Dr. Jayaraman, a nephrology fellow at Lankenau Hospital in Wynnewood, Pa., and associates reviewed the records of 380 patients who underwent coronary angiography in August 2001-January 2004, to evaluate a N-acetylcysteine protocol that was instituted in 2001.

Patients received 600 mg of oral N-acetylcysteine twice daily on the day before and the day of the procedure and were followed for 48 hours. By definition, low-risk patients had a serum creatinine level of 1.5 mg/dL or less; high-risk patients were those with more than 1.5 mg/dL.

Among the 318 low-risk patients, there were 8 cases (3%) of contrast-related acute renal failure (ARF). In the 62 high-risk patients, there were 12 cases of ARF (19%). In the low-risk group, 9% of patients received acetylcysteine, compared with 86% of those in the high-risk group.

The investigators concluded that acetylcysteine had a significant effect on the risk of ARF in high-risk, but not low-risk patients. Only about 10% of the high-risk patients who got the drug developed ARF.

PHILADELPHIA — Giving N-acetylcysteine as an adjunctive agent may reduce the risk of acute renal injury following contrast imaging procedures in high-risk patients, Dr. Venkatesh Jayaraman reported at the annual meeting of the American Society of Nephrology.

Dr. Jayaraman, a nephrology fellow at Lankenau Hospital in Wynnewood, Pa., and associates reviewed the records of 380 patients who underwent coronary angiography in August 2001-January 2004, to evaluate a N-acetylcysteine protocol that was instituted in 2001.

Patients received 600 mg of oral N-acetylcysteine twice daily on the day before and the day of the procedure and were followed for 48 hours. By definition, low-risk patients had a serum creatinine level of 1.5 mg/dL or less; high-risk patients were those with more than 1.5 mg/dL.

Among the 318 low-risk patients, there were 8 cases (3%) of contrast-related acute renal failure (ARF). In the 62 high-risk patients, there were 12 cases of ARF (19%). In the low-risk group, 9% of patients received acetylcysteine, compared with 86% of those in the high-risk group.

The investigators concluded that acetylcysteine had a significant effect on the risk of ARF in high-risk, but not low-risk patients. Only about 10% of the high-risk patients who got the drug developed ARF.

PHILADELPHIA — Giving N-acetylcysteine as an adjunctive agent may reduce the risk of acute renal injury following contrast imaging procedures in high-risk patients, Dr. Venkatesh Jayaraman reported at the annual meeting of the American Society of Nephrology.

Dr. Jayaraman, a nephrology fellow at Lankenau Hospital in Wynnewood, Pa., and associates reviewed the records of 380 patients who underwent coronary angiography in August 2001-January 2004, to evaluate a N-acetylcysteine protocol that was instituted in 2001.

Patients received 600 mg of oral N-acetylcysteine twice daily on the day before and the day of the procedure and were followed for 48 hours. By definition, low-risk patients had a serum creatinine level of 1.5 mg/dL or less; high-risk patients were those with more than 1.5 mg/dL.

Among the 318 low-risk patients, there were 8 cases (3%) of contrast-related acute renal failure (ARF). In the 62 high-risk patients, there were 12 cases of ARF (19%). In the low-risk group, 9% of patients received acetylcysteine, compared with 86% of those in the high-risk group.

The investigators concluded that acetylcysteine had a significant effect on the risk of ARF in high-risk, but not low-risk patients. Only about 10% of the high-risk patients who got the drug developed ARF.

CHICAGO — Perfusion computed tomography is a useful modality in the detection of regional brain perfusion deficits in patients with severe internal carotid artery stenosis, Dr. Agnieszka Trojanowska during a poster presentation at the annual meeting of the Radiological Society of North America.

CT perfusion imaging revealed that internal carotid artery stenosis in most cases was associated with brain perfusion deficits ipsilaterally to the stenotic site, and that hypoperfusion tended to improve considerably after stent placement, said Dr. Trojanowska, who also has a PhD.

In the study, 74 patients with symptomatic internal carotid artery stenosis of more than 70% were evaluated with CT perfusion imaging, on average, 70 hours before carotid stent placement and then 3 days and 6 months after stent placement. The protocol included a non-contrast enhanced transaxial CT of the brain with a 5-mm slice and 5-mm slope and dynamic CT perfusion imaging during administration of 50 mL of contrast medium at 4 mL/s with a 5-second delay.

Before stent placement with embolic protection devices, 84% of patients had perfusion deficits ipsilaterally to the stenotic site. Three days after stent placement, 30% of patients had perfusion deficits, and at 6 months, the deficits had diminished to 6%, said Dr. Trojanowska of the Medical University of Lublin (Poland).

A marked elongation of the mean transit time (6.2–6.8 seconds) was noted at the stenotic site, together with decreased values of cerebral blood flow (40–46 mL/100 g per min) and slightly increased cerebral blood volume (3.2 mL/100 g).

CHICAGO — Perfusion computed tomography is a useful modality in the detection of regional brain perfusion deficits in patients with severe internal carotid artery stenosis, Dr. Agnieszka Trojanowska during a poster presentation at the annual meeting of the Radiological Society of North America.

CT perfusion imaging revealed that internal carotid artery stenosis in most cases was associated with brain perfusion deficits ipsilaterally to the stenotic site, and that hypoperfusion tended to improve considerably after stent placement, said Dr. Trojanowska, who also has a PhD.

In the study, 74 patients with symptomatic internal carotid artery stenosis of more than 70% were evaluated with CT perfusion imaging, on average, 70 hours before carotid stent placement and then 3 days and 6 months after stent placement. The protocol included a non-contrast enhanced transaxial CT of the brain with a 5-mm slice and 5-mm slope and dynamic CT perfusion imaging during administration of 50 mL of contrast medium at 4 mL/s with a 5-second delay.

Before stent placement with embolic protection devices, 84% of patients had perfusion deficits ipsilaterally to the stenotic site. Three days after stent placement, 30% of patients had perfusion deficits, and at 6 months, the deficits had diminished to 6%, said Dr. Trojanowska of the Medical University of Lublin (Poland).

A marked elongation of the mean transit time (6.2–6.8 seconds) was noted at the stenotic site, together with decreased values of cerebral blood flow (40–46 mL/100 g per min) and slightly increased cerebral blood volume (3.2 mL/100 g).

CHICAGO — Perfusion computed tomography is a useful modality in the detection of regional brain perfusion deficits in patients with severe internal carotid artery stenosis, Dr. Agnieszka Trojanowska during a poster presentation at the annual meeting of the Radiological Society of North America.

CT perfusion imaging revealed that internal carotid artery stenosis in most cases was associated with brain perfusion deficits ipsilaterally to the stenotic site, and that hypoperfusion tended to improve considerably after stent placement, said Dr. Trojanowska, who also has a PhD.

In the study, 74 patients with symptomatic internal carotid artery stenosis of more than 70% were evaluated with CT perfusion imaging, on average, 70 hours before carotid stent placement and then 3 days and 6 months after stent placement. The protocol included a non-contrast enhanced transaxial CT of the brain with a 5-mm slice and 5-mm slope and dynamic CT perfusion imaging during administration of 50 mL of contrast medium at 4 mL/s with a 5-second delay.

Before stent placement with embolic protection devices, 84% of patients had perfusion deficits ipsilaterally to the stenotic site. Three days after stent placement, 30% of patients had perfusion deficits, and at 6 months, the deficits had diminished to 6%, said Dr. Trojanowska of the Medical University of Lublin (Poland).

A marked elongation of the mean transit time (6.2–6.8 seconds) was noted at the stenotic site, together with decreased values of cerebral blood flow (40–46 mL/100 g per min) and slightly increased cerebral blood volume (3.2 mL/100 g).