Science News & Science Current Events
 
Email a Friend Send to a friend
Printer Friendly Print Making waves in cancer detection

Making waves in cancer detection

July 23, 2002

We`re all familiar with X-rays being used to look inside our bodies. But according to physicists, medical imaging in the future is likely to be based on an as yet unused type of radiation known as terahertz radiation.

At the 26th International Conference on the Physics of Semiconductors in Edinburgh on Thursday 1 August, Dr David Whittaker from the University of Sheffield will describe how he, Dr Michael Johnston and co-workers at the University of Cambridge, produce short pulses of this terahertz radiation from a piece of semiconducting material. Their pulses are more powerful than any generated by the same method so far, and increase the chances of a commercially viable imaging system - such as a detection system for skin cancer - being developed.




Terahertz radiation - also known as T-rays - is part of the broad spectrum of electromagnetic radiation that also includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. All electromagnetic radiation travels in waves, and radio waves have the longest wavelengths (the distance between two crests of these waves) in the spectrum, while gamma rays have the shortest. T-rays lie within the infrared region of the spectrum, close to the microwave region, and have a wavelength of about one tenth of a millimetre. This makes them ideal candidates for certain types of medical imaging as they are too large to scatter randomly off cell walls, but small enough to provide images with useful resolution.

"One company, TeraView Ltd in the UK, is using terahertz radiation to look at the various layers in skin. It allows you to see the boundaries between the layers, and the thickness of the layers" says Dr Whittaker. This is because water absorbs terahertz radiation, and since each layer of our skin contains a different amount of moisture, the different layers will absorb a different percentage of the T-rays shone at them.

The boundaries between the layers also reflect some T-rays. So by measuring the time taken for a T-ray pulse to be reflected back from a boundary beneath a layer of skin, the thickness of that layer can be determined. "The hope is that you could produce images of skin tumours and distinguish the benign ones from the malignant ones by differences in layer thickness" explains Dr Whittaker.

The Cambridge/Sheffield team produce their T-ray pulses by shining extremely short pulses of laser light at the surface of a semiconductor. The energy in each laser pulse is enough to move electrons (sub-atomic particles) from their normal positions inside the semiconductor. The spaces the displaced electrons leave behind are known as `holes`, and in semiconductors the steady movement of either electrons or holes - which both carry electric charge - causes an electric current to flow. Accelerating electric charges emit electromagnetic radiation, and in this case the electrons and holes begin accelerating, and create a small electric current and a pulse of terahertz radiation before they start slowing down again.

By placing a specially designed prism onto the semiconductor surface, the researchers have managed to produce the strongest pulses yet via such a technique. This method lines up the electrons and holes in such a way that around 20 times more of the terahertz radiation they emit leaves the surface of the semiconductor than in other systems, where almost all of it remains trapped inside.

Less powerful T-ray sources are already being used in trials to test the viability of a skin cancer detection system. "Hopefully the sources we`re producing will be more effective" says Dr Whittaker. "For any imaging application, the time taken to acquire the image decreases as you increase the power of your source, and if you can get a good signal more quickly, you can scan more quickly" he adds.

Not only could such a method of medical imaging be quick, it should also be much safer than X-rays. This is because unlike X-rays, T-rays don`t contain enough energy to remove electrons from their parent atoms in cells. This is important, as it is this removal of electrons that makes cells more likely to mutate. The relative safety of terahertz radiation means similar systems could be used for scanning baggage at airports, or by the cosmetics industry for measuring the effectiveness of moisturisers. And by using terahertz radiation in the same way that radio waves are used to carry signals to and from our mobile phones, a new method of wireless communication could even be created.

"The idea is to use it for free space networks within buildings for faster communication between computers" explains Dr Whittaker. Each computer in a network would have a transmitter and a receiver, and files and e-mails would be beamed around the room via T-rays, removing the need for a tangle of wires connecting the machines. "Because it is absorbed by walls and by water in the atmosphere, terahertz radiation gives you security and also provides isolation between different buildings" adds Whittaker.

Institute of Physics



Related Aging Current Events and Aging News Articles Aging Current Events and Aging News RSS Aging Current Events and Aging News RSS
Children with cystic fibrosis not well covered by guidelines for vitamin D needs
Existing recommendations for treating vitamin D deficiency in children with cystic fibrosis (CF) are too low to cover the serious need, leaving most at high risk for bone loss and rickets, according to researchers at Johns Hopkins Children's Center.

'Smile doctors' create, restore and enhance patients' smiles
Imagine not having the ability to return the smile of a loved one or being too embarrassed by your mouth's appearance to display a smile.

Waterborne disease risk upped in Great Lakes
An anticipated increased incidence of climate-related extreme rainfall events in the Great Lakes region may raise the public health risk for the 40 million people who depend on the lakes for their drinking water, according to a new study.

Circadian clock may be critical for remembering what you learn, Stanford researchers say
The circadian rhythm that quietly pulses inside us all, guiding our daily cycle from sleep to wakefulness and back to sleep again, may be doing much more than just that simple metronomic task, according to Stanford researchers.

Case Western Reserve University research finds drug candidate slows age-related macular degeneration
Research results from the Case Western Reserve University School of Medicine show that the progression of age-related macular degeneration (AMD) is markedly slowed in new laboratory-engineered mice when they received treatments of retinylamine, a trial drug that has been tested in a medical school lab.

Anti-cancer drug prevents, reverses cardiovascular damage in mouse model of premature aging disorder
An experimental anti-cancer drug can prevent -- and even reverse -- potentially fatal cardiovascular damage in a mouse model of progeria, a rare genetic disorder that causes the most dramatic form of human premature aging, National Institutes of Health (NIH) researchers reported today.

Emerging model organisms featured in CSH Protocols
Biological research has long relied on a small number of model organisms, species chosen because they are amenable to laboratory research and suitable for the study of a range of biological problems.

When cells go bad
When a cell's chromosomes lose their ends, the cell usually kills itself to stem the genetic damage. But University of Utah biologists discovered how those cells can evade suicide and start down the path to cancer.

New study proves that pain is not a symptom of arthritis, pain causes arthritis
Pain is more than a symptom of osteoarthritis, it is an inherent and damaging part of the disease itself, according to a study published today in journal Arthritis and Rheumatism.

Restless nights put older adults at risk for depression recurrence
Nearly 60 percent of the nation's elderly have trouble sleeping, whether it's a lot of tossing and turning or outright bouts of insomnia. While for most people sleeplessness can be annoying at best or unhealthy at worst, for elderly individuals who have suffered from depression in the past, poor sleep may be the first sign that a new bout of depression is coming on.
More Aging Current Events and Aging News Articles


The Mind-Beauty Connection: 9 Days to Reverse Stress Aging and Reveal More Youthful, Beautiful Skin
by Amy Wechsler

It’s not your age that’s causing half of those lines and crinkles. It’s your life. Now, Amy Wechsler, MD shows you how to de-stress your skin and take years—years—off your face. In 9 days. Liking the way you look is vital to your health and happiness. But that’s not easy when life runs at warp speed—you’re simultaneously coping with ever-increasing demands: dependent...



Healthy Aging: A Lifelong Guide to Your Well-Being
by Andrew Weil

In each of his widely acclaimed, best-selling books, Dr. Andrew Weil has been an authoritative and companionable guide through a uniquely effective combination of traditional and nontraditional approaches to health and healthy living. Now he gives us a book about aging that is unlike any other. Drawing on the new science of biogerontology (the biology of aging) as well as on the secrets of...



Aging Well: Surprising Guideposts to a Happier Life from the Landmark Harvard Study of Adult Development
by George E. Vaillant

Now in paperback, the acclaimed bestseller that reveals the scientific secrets to ensuring that our golden years are truly golden. Based on the longest and most complete study of adult development in the world, AGING WELL draws from the individual histories of 824 men and women from a variety of backgrounds to illustrate the most important factors involved in reaching and enjoying a happy,...



Adult Development and Aging
by John C. Cavanaugh, Fredda Blanchard-Fields

Written within a biopsychosocial framework, Cavanaugh and Blanchard-Fields' best-selling text covers the specific ages-stages of adult development and aging. In its unparalleled coverage of current research and theory, the authors draw clear connections between research and application. The book's focus on "positive aging" and the gains and losses people experience across adulthood distinguish it...



Reverse Aging (Chinese)
by Sang Whang

This a Chinese translation of the best selling science and health book "Reverse Aging" (0966236319), sold on...



Aging With Grace: What the Nun Study Teaches Us About Leading Longer, Healthier, and More Meaningful Lives
by David Snowdon

In 1986 Dr. David Snowdon, one of the world’s leading experts on Alzheimer’s disease, embarked on a revolutionary scientific study that would forever change the way we view aging—and ultimately living. Dubbed the “Nun Study” because it involves a unique population of 678 Catholic sisters, this remarkable long-term research project has made headlines worldwide with its provocative...



Aging and The Life Course: An Introduction to Social Gerontology
by Jill Quadagno

This groundbreaking text is the first to take a life course perspective, examining the relationship between the quality of one's life in old age and one’s experiences, earlier choices, opportunities, and constraints. The text gives students a broad background for understanding current policy debates through a distinctive chapter entitled "Old Age and the Welfare State" (Chapter 11) and through...



Ending Aging: The Rejuvenation Breakthroughs That Could Reverse Human Aging in Our Lifetime
by Aubrey de Grey, Michael Rae

With a New AfterwordMust We Age?Nearly all scientists who study the biology of aging agree that we will someday be able to substantially slow down the aging process, extending our productive, youthful lives. Dr. Aubrey de Grey is perhaps the most bullish of all such researchers. As has been reported in media outlets ranging from 60 Minutes to The New York Times, Dr. de Grey believes that the key...



Aging, the Individual, and Society
by Susan M. Hillier, Georgia M. Barrow

In the coming years, understanding senior citizens will be more important than it's ever been. Are you ready? AGING, THE INDIVIDUAL, AND SOCIETY introduces you to gerontology in a compassionate way that helps you understand them and know how to work with them. It's balanced between academic and practical discussions, and packed with study tools. That way, you'll ace the class and be ready for the...



How to Care for Aging Parents (Morris, How to Care for Aging)
by Virginia Morris, Robert M. Butler

The best and bestselling book of its kind. Originally published in 1995, How to Care for Aging Parents, with 220,000 copies in print, won a Books for a Better Life Award and was praised as "an indispensable book" (AARP) and "a compassionate guide of encyclopedic proportion" (The Washington Post). It also catapulted its author, Virginia Morris, to national prominence as a recognized eldercare...

© 2008 BrightSurf.com