"This is an important study, because it demonstrates that atherosclerosis in an artery outside the heart is an independent predictor of adverse cardiovascular events," said the study's lead author, Christopher D. Maroules, M.D., a radiology resident at the University of Texas Southwestern Medical Center in Dallas and lead author. "MRI is a promising tool for quantifying atherosclerosis through plaque and arterial wall thickness measurements."
Atherosclerosis is a condition in which fat, cholesterol and other substances collect within the arteries, forming plaque. As plaque accumulates, the artery narrows, limiting blood flow. The condition can occur in any artery, including the cerebral (brain) and coronary (heart) arteries and the aorta, which carries oxygenated blood from the heart through the abdomen to the rest of body. The aorta is the largest artery body.
In the study, researchers analyzed abdominal MR images of 2,122 participants (mean age 44) in the Dallas Heart Study, a multiethnic population-based study of healthy adults from Dallas County, Texas. Two measurements were obtained from the MR images: mean abdominal aortic wall thickness, or the thickness of the vessel wall, and the amount of plaque buildup, referred to as the aortic plaque burden.
Following imaging, study participants were monitored for a period of 7.8 years. During that time, 143 participants experienced an adverse cardiovascular event in which arterial blood flow was obstructed, resulting in death or medical intervention. Researchers categorized the events as related to the heart (cardiac events) or to other arteries (called extra-cardiac vascular events) such as those in the brain or abdomen.
Of the 143 cardiovascular events, 34 were fatal. Seventy-three were non-fatal cardiac events, including heart attack or coronary revascularization, and 46 were non-fatal extra-cardiac vascular events, such as stroke or carotid revascularization.
Using the MRI measurements, the researchers found that increased abdominal aortic wall thickness correlated with a greater risk for all types of cardiovascular events. An increase in both wall thickness and aortic plaque burden was associated with an increased risk for non-fatal extra-cardiac vascular events.
"These MRI measurements may add additional prognostic value to traditional cardiac risk stratification models," Dr. Maroules said.
MR imaging of the abdominal aorta is less technically challenging than other vascular imaging exams because of the large size of the vessel and its lack of proximity to a moving organ, such as the heart or the lungs. In addition, images of the abdominal aorta are often captured when patients undergo other exams, such as MRI of the spine or abdomen.
"The abdominal aorta is incidentally imaged on a regular basis," Dr. Maroules said. "Radiologists can infer prognostic information from routine MRI exams that may benefit patients by identifying subclinical disease."
According to Dr. Maroules, further MRI research will contribute to a better understanding of the progression of atherosclerosis, which scientists believe begins with a remodeling or thickening of the vessel wall prior to the buildup of plaque.
"Abdominal Aortic Atherosclerosis at MR Imaging Is Associated with Cardiovascular Events: The Dallas Heart Study." Collaborating with Dr. Maroules were Eric Rosero, M.D., Colby Ayers, M.S., Ronald M. Peshock, M.D., and Amit Khera, M.D., M.Sc.
Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc.
RSNA is an association of more than 51,000 radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Ill. (RSNA.org)
For patient-friendly information on MRI, visit RadiologyInfo.org.
Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin
Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
24.05.2017 | Physics and Astronomy
24.05.2017 | Physics and Astronomy
24.05.2017 | Event News