Obese patients face higher radiation exposure from CT scans -- but new technology can help

Engineering researchers at Rensselaer Polytechnic Institute develop 'phantoms' to make medical imaging safer for overweight individuals

2012-04-05

(Press-News.org) Troy, N.Y. – Most medical imaging equipment is not designed with overweight and obese patients in mind. As a result, these individuals can be exposed to higher levels of radiation during routine X-ray and CT scans.

A new study from Rensselaer Polytechnic Institute is the first to calculate exactly how much additional radiation obese patients receive from a CT scan. Research results show the internal organs of obese men receive 62 percent more radiation during a CT scan than those of normal weight men. For obese women, it was an increase of 59 percent.

New technology developed at Rensselaer by nuclear engineering expert X. George Xu could help solve this problem. Xu's research team created ultra-realistic 3-D computer models of overweight and obese men and women, and used computer simulations to determine how X-rays interact with the different body types. These models, known as "phantoms," can help empower physicians to configure and optimize CT scanning devices in such a way that minimizes how much radiation a patient receives.

"Radiation exposure is cumulative over a patient's lifetime. The risk associated with a radiation dose from a single CT scan is relatively small when compared with the clinical benefit of the procedure. But patients are increasingly undergoing multiple CT scans and other radiation-based procedures, which can lead to unnecessary radiation risk. Regretfully, our study shows that obese and overweight patients can be exposed to an even greater level of radiation," said Xu, head of the Nuclear Engineering Program and a professor in the Department of Mechanical, Aerospace, and Nuclear Engineering (MANE) at Rensselaer. "Our new study brings us one step closer to minimizing radiation exposure and mitigating this risk to patients."

Results of the Xu's study were published today in the journal Physics in Medicine & Biology. The study may be viewed online at: http://m.iopscience.iop.org/0031-9155/57/9/2441

Currently, if technicians use normal equipment settings to perform a CT scan on an obese patient, the resulting images are blurry as the X-ray photons have to travel further and make their way through layers of fat. As a result, technicians generally adjust the equipment to a more powerful setting, which produces a better image but exposes the obese patient to additional radiation. There is no mechanism for discerning the setting levels that will provide an optimal balance of the highest image clarity and the lowest radiation dose.

These new phantoms for overweight and obese patients will be part of a forthcoming software package, VirtualDose, developed by Xu and his team. VirtualDose aims to enable the creation of a personalized, ultra-realistic phantom of any patient undergoing a CT scan. The program takes into consideration a patient's individual characteristics, including age, sex, height, weight, and even if a woman is pregnant. By entering these data into the software, VirtualDose quickly creates a phantom that accurately models the patient's internal organs. These phantoms will allow physicians and researchers to compare the radiation doses a patient will get from different CT scanner settings, and then choose the most appropriate configuration.

VirtualDose will also enable physicians to keep a highly accurate record of how much radiation patients are exposed to over their lifetime. California recently became the first state in the United States to require radiation dose records for patients undergoing CT examinations.

INFORMATION:

Along with Xu, authors of the study are research associate Aiping Ding; graduate students Matthew Mille and Tianyu Liu; and lecturer and campus radiation safety officer Peter Caracappa, all of the Nuclear Engineering Program and MANE at Rensselaer.

The research is funded primarily by the National Institutes of Health (NIH), with additional support from the National Institute of Biomedical Imaging and Bioengineering, the U.S. Department of Energy (DOE) Office of Nuclear Energy's Nuclear Energy University Programs (NEUP), and the Health Physics Society.

The Nuclear Engineering Program at Rensselaer is among the oldest in the nation, dating back to the late 1950s when the university built an electron accelerator.

For more information on Xu's research at Rensselaer, visit:

Wall Street Journal: Scientists Find Safer Ways To Test Medical Procedures

Patient Safety: Reducing the Risks of Radiation Exposure From CT Scans and X-Rays

Safer, More Accurate Radiation Therapy for Expecting Mothers

The Phantom Patient

A Virtual Patient To Simulate Real-Time Organ Motions

Rensselaer Radiation Measurement and Dosimetry Group

Nuclear Engineering Program

Visit the Rensselaer research and discovery blog: http://approach.rpi.edu
Follow us on Twitter: www.twitter.com/RPInews

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

Industry Regulator ACMA Warns Australian Comms Providers to Clarify Telecoms Buzzwords

2012-04-05

ACMA, the Australian Communications and Media Authority, has demanded that all the country's telecoms providers must clarify their use of industry terms to help subscribers enjoy greater peace of mind and fairness. The regulator is focusing on terms like 'cap' and 'unlimited plans' as it seeks to drive through greater equality and clearness for consumers. ACMA wants providers to commit to making subscribers' lives easier by signing up to a voluntary code of conduct which sees all operators pledge to remove misleading terms from contracts and advertising. 'Unlimited ...

Deaf children's gesture mismatches provide clues to learning moments

2012-04-05

In a discovery that could help instructors better teach deaf children, a team of University of Chicago researchers has found that a gesture-sign mismatch made while explaining a math problem suggests that a deaf child is experiencing a teachable moment. Through a series of experiments with 40 deaf children, ages nine through 12, all of whom were fluent in American Sign Language, researchers were able to distinguish between ASL signs and gestures that look like the gestures hearing children produce when explaining the same math problems. The deaf students who expressed ...

Ex-Spouse Missing Payments? You Might be Held Responsible

2012-04-05

Going through a divorce can be an extremely difficult time. The decision to finally end a marriage and move on usually comes after a lot of soul-searching. It is not easy to walk away from someone who has been such a major part of your life. The entire process can be a long, drawn-out affair that can be emotionally draining, and it may be tempting to try to get the divorce over as soon as possible to move on. However, most people do not realize the severe economic challenges that may arise as a result of the divorce until it is too late. Whether it is a house, car or ...

Physicians less likely to prescribe antidepressants to minorities, Medicaid patients

2012-04-05

ANN ARBOR, Mich.--- African-Americans and Hispanics with major depressive disorder are less likely to get antidepressants than Caucasian patients, and Medicare and Medicaid patients are less likely to get the newest generation of antidepressants. Researchers from the University of Michigan School of Public Health examined data from 1993 to 2007 to try to understand the antidepressant prescribing patterns of physicians. They looked at two things: who received antidepressants, and what type of antidepressant was prescribed. They found that race, payment source, physician ...

Tiny hitchhikers attack cancer cells

2012-04-05

Nanotechnology offers powerful new possibilities for targeted cancer therapies, but the design challenges are many. Northwestern University scientists now are the first to develop a simple but specialized nanoparticle that can deliver a drug directly to a cancer cell's nucleus -- an important feature for effective treatment. They also are the first to directly image at nanoscale dimensions how nanoparticles interact with a cancer cell's nucleus. "Our drug-loaded gold nanostars are tiny hitchhikers," said Teri W. Odom, who led the study of human cervical and ovarian ...

Bascom Palmer Eye Institute marks breakthrough in IOP regulation in fight against glaucoma

2012-04-05

Miami… A six-year collaboration between two faculty members of Bascom Palmer Eye Institute of the University of Miami Miller School of Medicine has yielded new insight regarding the regulation of intraocular pressure (IOP) in glaucoma - an irreversible blinding disease that causes progressive visual impairment due to optic nerve damage and is the leading cause of blindness worldwide. The key finding by associate professors of ophthalmology Richard K. Lee, M.D., Ph.D. and Sanjoy Bhattacharya, M. Tech., Ph, D. validates their hypothesis that the response of aqueous humor ...

Spike in Teenage Deaths Has North Carolina Groups Ready for Action

2012-04-05

One of the defining moments for teenagers in the U.S. is earning a driver's license, which equates to gaining some independence from parental supervision. This defining moment can quickly turn devastating, however, due to various factors like disobeying traffic laws and distracted driving. There has been an alarming spike recently in the number of teenagers who die in car accidents each year across the nation. Particularly in North Carolina, the rate of teenage driver deaths is on the rise, so safety groups in the state are ready for action. Spike in Deaths According ...

New lab mice cut search for genetic links to disease by more than a decade

2012-04-05

With a 95 percent genomic similarity to humans, mice have long been used to learn about the genetic causes of human disease. Once researchers can shine a light on the genetic factors that cause disease in mice, they can start to develop prevention and treatment options to protect the human population. But this process, called genetic mapping, is a long and difficult road, made more challenging by the 5% difference between the humans and lab mice. Now Prof. Fuad Iraqi of Tel Aviv University's Sackler Faculty of Medicine is closing the gap with an international project ...

Dangerous blood pressure medicine

2012-04-05

Despite the fact that nifedipine increases the risk of heart attacks and death, doctors still prescribe this immediate-release blood pressure drug to elderly patients. The Cologne-based research group led by Ingrid Schubert has now published the results of their investigation in the current issue of Deutsches Ärzteblatt International (Dtsch Arztebl Int 2012; 109[12]: 215-9). Immediate-release nifedipine is classified as a potentially dangerous drug in the PRISCUS list published in 2010. Earlier studies demonstrated that, in comparison to other antihypertensive drugs, ...

Expungement of Criminal Records in New Jersey

2012-04-05

If you have been arrested or convicted of a crime in New Jersey, you may simply want to move on with life without a criminal record haunting you in the future. It is true in many respects that decisions made earlier in life are not reliable indicators of future behavior. Unfortunately, many people still see trouble in a criminal record. Certain employers may choose to pass you by, rental agencies may disqualify you and military recruiters can be particularly sensitive about criminal records. In an effort to promote ex-offender re-entry back into the community, the law allows ...

Obese patients face higher radiation exposure from CT scans -- but new technology can help

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: