News | February 04, 2009

PROTECTION I Study Reveals Lower Radiation Doses in Cardiac CT

February 4, 2009 - In recent years, cardiac computed tomography angiography (CTA) has emerged as a useful diagnostic imaging modality for the assessment of coronary artery disease (CAD), and new research shows there are significantly lower doses of radiation associated with cardiac CTA than have been previously reported in several earlier studies.

The new study, the Prospective Multicenter Study On Radiation Dose Estimates Of Cardiac CT Angiography in Daily Practice I (PROTECTION I), published in this week’s Journal of the American Medical Association, confirms that it is entirely possible to significantly reduce the radiation dose in adequately selected patients. The study showed there is a wide degree of variability in radiation doses between sites.

The study, led by Dr. Jorg Hausleiter, Deutsches Herzzentrum München, Klinik an der Technischen Universität München in Munich, Germany, was observational and included 1,965 patients undergoing cardiac CTA between February and December 2007.

Researchers worldwide analyzed the results to identify independent predictors of radiation dose, measured as dose-length product (DLP). DLP is a reflection of the total amount of radiation deposited over the entire set of images during a patient’s CT. More familiar to most is the effective dose, measured in millisieverts (mSV), which was derived from the organ weighting factor for the chest. In PROTECTION I, the average dose was 12 mSV, which is notably lower than several earlier studies of cardiac CTA radiation doses.

PROTECTION I called attention to the varying degrees of radiation doses delivered between sites – specifically, the median DLP at the highest dose site was over six times that of the lowest dose site, and the remaining doses in between ran the gamut. Hausleiter and his colleagues identified several currently available key dose- reduction strategies which can be implemented in many more patients which would drive the average dose down even further: electrocardiographically controlled tube modulation (ECTCM), scan length, voltage and the use of sequential scanning. For example, with use of ECTCM, a 25 percent dose-reduction was achieved. The findings suggest that these dose-reduction methods can be used in the majority of patients, which should alert cardiac CT laboratories that they need to implement these strategies when performing cardiac CTA.

“Reducing the amount of radiation to the patient is something that is on the mind of virtually all physicians involved in cardiac CT,” said Daniel S. Berman, M.D. of Cedars-Sinai Medical Center and president of the Society of Cardiovascular Computed Tomography. “The amount of radiation now associated with cardiac CT is very similar to that of many other x-ray and nuclear medicine procedures. Coronary CT angiography is the most accurate noninvasive test for the detection of coronary artery disease. Given the low doses of radiation involved, when there is suspicion but not clear evidence that a patient has a blockage in a coronary artery needing evaluation, it is clearly safer to perform a coronary CT angiogram than to perform an invasive coronary angiogram.”

This study complements other recent studies of cardiac CTA that prove its excellent diagnostic accuracy compared to invasive angiography. Using the protocols identified in PROTECTION I, quality improvement measures should be developed to decrease the radiation potential in cardiac CTA. With lower radiation doses, the risk benefit equation shifts even more in favor of cardiac CTA as a first line diagnostic test for the evaluation of chest pain in appropriately selected patients.

The Society of Cardiovascular Computed Tomography (SCCT) is the recognized representative and advocate for physicians, scientists, and technologists who work in the field of cardiovascular computed tomography. With nearly 4000 members, SCCT is nationally and internationally viewed as the principal organization committed to the further development of cardiovascular computed tomography through research, education, quality and advocacy.

For more information: www.scct.org

Related Content

X-ray of a knee replacement. CMS may change reimbursements for joint and knee replacements. Patient Marilyn Fornell.

CMS may change how it reimburses for knee replacements and said it may eliminate bundled payments for acute cardiac care.

Feature | Business | August 16, 2017 | Dave Fornell
August 16, 2017 — The Centers for Medicare and Medicaid Services (CMS) announced a proposed rule to reduce the number
MRI Reveals Striking Brain Differences in People with Genetic Autism

Example images for a control participant , a deletion carrier, and a duplication carrier. In the sagittal image of the deletion carrier, the thick corpus callosum, dens and craniocervical abnormality, and cerebellar ectopia are shown. For the duplication carrier, the sagittal image shows the thin corpus callosum and the axial image shows the increased ventricle size and decreased white matter volume. Image courtesy of the Radiological Society of North America (RSNA).

News | Neuro Imaging | August 09, 2017
August 9, 2017 — In the first major study of its kind, researchers using magnetic...
Moffitt Cancer Center Enhances Patient Care with Toshiba Medical's Infinix-i 4-D
News | Interventional Radiology | August 03, 2017
Cancer patients at Moffitt Cancer Center in Tampa, Fla., now have access to advanced diagnostic imaging for fast and...
Clinical Data Supports Use of Xoft System for Endometrial Cancer
News | Brachytherapy Systems | August 03, 2017
Researchers presented clinical data supporting use of the Xoft Axxent Electronic Brachytherapy (eBx) System for the...
brain with chronic traumatic injury
News | Magnetic Resonance Imaging (MRI) | August 02, 2017
Fighters are exposed to repeated mild traumatic brain injury (mTBI), which has been associated with neurodegenerative...
NIH-funded scientists have discovered that Parkinson’s disease increases the amount of “free” water in a particular brain area

NIH-funded scientists have discovered that Parkinson’s disease increases the amount of “free” water in a particular brain area. Image courtesy of David Vaillancourt, Ph.D., University of Florida.

News | Neuro Imaging | July 31, 2017
Scientists at the University of Florida have discovered a new method of observing the brain changes caused by Parkinson...
more healthcare providers and patients are choosing options such as Gamma Knife stereotactic radiosurgery
News | Radiation Therapy | July 31, 2017
Each year, up to 650,000 people who were previously diagnosed with various forms of cancer will develop brain...
Contrast Media from Bayer, trends in contrast media and developments in contrast media
Feature | Contrast Media | July 28, 2017 | By Dave Fornell
Here are several updates in medical imaging ...
"Residual Echo" of Ancient Humans May Hold Clues to Mental Disorders

MRI data shows (left) areas of the skull preferentially affected by the amount of Neanderthal-derived DNA and (right) areas of the brain’s visual system in which Neanderthal gene variants influenced cortex folding (red) and gray matter volume (yellow). Image courtesy of Michael Gregory, M.D., NIMH Section on Integrative Neuroimaging

News | Neuro Imaging | July 26, 2017
Researchers from the National Institute of Mental Health (NIMH) have produced the first direct evidence that parts of...
New York Hospital Finds Significant Cost Savings With Toshiba’s Aquilion One CT
News | Computed Tomography (CT) | July 25, 2017
In five years, Kaleida Health’s Stroke Care Center (SCC) at the Gates Vascular Institute in Buffalo, N.Y., has realized...
Overlay Init