"Coronary CT angiography has generated great enthusiasm in recent years, due to its diagnostic accuracy in assessing patients with known or suspected coronary artery disease," said Andrew J. Einstein, M.D., Ph.D., assistant professor of clinical medicine in radiology and director of cardiac CT research at Columbia University Medical Center. "However, that enthusiasm has been tempered by concern about the potentially high radiation dose received by patients."
In CT, numerous x-ray beams and a set of x-ray detectors rotate around the patient, measuring the amount of radiation being absorbed in the body. At the same time, the exam table moves through the scanner allowing the x-ray beam to follow a helical or spiral path.
Many coronary CT angiography exams are conducted on 64-detector row CT scanners, which can image four centimeters at a time. The latest generation of CT technology, a 320-detector row volume CT scanner, can image 16 centimeters—or the entire length of the heart—in a single rotation and within a single heartbeat.
In his study, Dr. Einstein and a team of researchers compared the radiation exposure incurred during a coronary CT angiography procedure using a 64-detector row helical scanning and volume scanning, using a 320-detector row volume CT scanner. Phantoms simulating the male and female body were imaged using six different scan modes.
Using standard 64-detector row helical scanning as the benchmark, the effective radiation dose was reduced by 91 percent from 35.4 millisieverts (mSv) to 4.4 mSv using optimized 320-detector row volume scanning.
"By imaging the entire heart in one piece, volume scanning eliminates artifacts due to seams or gaps between image sections," said Dr. Einstein. "Moreover, the x-ray tube is left on for only a brief duration, as little as .35 seconds."
According to Dr. Einstein, state-of-the-art CT technology emphasizes optimal image resolution with the ability to lower radiation dose through a variety of features and scan modes that adjust and modulate the dose based on the specific needs of the individual patient.
"As CT technology advanced from 16- to 64-slice capabilities, the radiation dose went up significantly," he said. "Today, technology development is going in the opposite direction, reducing radiation exposure."
Dr. Einstein emphasized that practitioners must pay careful attention to using the appropriate scan mode to obtain diagnostic information with the least amount of radiation exposure to the patient.
"Radiation Dose from Single-Heartbeat Coronary CT Angiography Performed with a 320-Detector Row Volume Scanner." Collaborating with Dr. Einstein were Carl D. Elliston, M.A., Andrew E. Arai, M.D., Marcus Y. Chen, M.D., Richard Mather, Ph.D., Gregory D. N. Pearson, M.D., Ph.D., Robert L. DeLaPaz, M.D., Edward Nickoloff, D.Sc, Ajoy Dutta, M.S., and David J. Brenner, Ph.D., D.Sc.
Disclosure: Dr. Mather is an employee of Toshiba America Medical Systems. Dr. Mather provided recommendations but had no control over the data included in the manuscript.
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. (http://radiology.rsnajnls.org/)
RSNA is an association of more than 44,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. (RSNA.org)
For patient-friendly information on CT angiography, visit RadiologyInfo.org.
Inflammation Triggers Unsustainable Immune Response to Chronic Viral Infection
24.10.2016 | Universität Basel
Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering