"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.
Routing gene therapy directly into the brain
07.12.2017 | Boston Children's Hospital
New Hope for Cancer Therapies: Targeted Monitoring may help Improve Tumor Treatment
01.12.2017 | Berliner Institut für Gesundheitsforschung / Berlin Institute of Health (BIH)
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
11.12.2017 | Physics and Astronomy
11.12.2017 | Materials Sciences
11.12.2017 | Earth Sciences