Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

File compression can expand mammography’s power

21.12.2005


When it comes to the information in a mammogram, Purdue scientists say less is more – and their findings could bring medical care to many far-flung communities.



A team of researchers, including Bradley J. Lucier, has found that digitized mammograms, the X-ray cross sections of breast tissue that doctors use to search for cancer, are actually interpreted more accurately by radiologists once they have been "compressed" using techniques similar to those used to lessen the memory demand of images in digital cameras. Though compression strips away much of the original data, it still leaves intact those features that physicians need most to diagnose cancer effectively. Perhaps equally important, digitization could bring mammography to many outlying communities via mobile equipment and dial-up Internet connections.

"Any technique that improves the performance of radiologists is helpful, but this also means that mammograms can be taken in remote places that are underserved by the medical community," said Lucier, who is a professor of mathematics and computer science in Purdue’s College of Science. "The mammograms can then be sent electronically to radiologists, who can read the digitized versions knowing they will do at least as well as the original mammograms."


The research paper will appear in today’s (Dec. 20) issue of Radiology, the journal of the Radiological Society of North America. Lucier developed the file-compression method used in the study, which was run at the Moffitt Cancer Center at the University of South Florida in Tampa.

Discerning the potential seeds of cancer within the chaff of extraneous detail present in a mammogram requires the expert eye of a radiologist, who must pick out salient features at many different scales within the image. Clues can be very small clusters of tiny calcium deposits, each less than one-hundredth of an inch in diameter. Clues also can range up through the edges of medium-sized objects – which could be benign cysts with smooth edges, for example, or cancerous tumors with rough edges – up to large-scale patterns in tissue fiber.

"The edges of tumors are where growth occurs, and they tell radiologists whether what they see is a tumor or not," Lucier said. "You have to keep all these features intact when you compress the image if it is to be useful."

Once a mammogram image has been converted into electronic form, it can contain more than 50 megabytes of data, which makes it prohibitively large for transmission by computer modem over a telephone line. Compounding the issue is that four such images are needed for a complete screening, and though it takes only a few minutes to obtain the X-ray pictures, getting a mammogram can be difficult. A 2001 FDA study showed that the number of mammography facilities has declined in most states, and the population of potential recipients of mammography services has increased. While the study suggests that difficulties obtaining mammograms are localized rather than widespread, Lucier said that telemedicine could potentially mitigate the problem.

"I began experimenting with file-compression algorithms to see if we could shrink files to the point where they could be sent over standard phone lines," he said. "Some communities do not have easy access to broadband Internet yet, and my colleagues and I wanted to work around that issue."

Lucier found that one well-tested algorithm – a short set of instructions that can be repeated many times – did the trick after a bit of tweaking. Though the basic mathematics has been around for more than a decade, he said, its finer points required some adjusting.

"I wanted the algorithm to make all the features important to radiologists degrade at the same rate – both the edges of large tumors and the smallest calcium deposits," Lucier said. "I tried several approaches and eventually got a balance that seemed reasonable, based on what radiologists tell me they want."

His methods have evidently paid off: On seven of nine measures of diagnostic accuracy, radiologists interpret the compressed images more accurately than they interpret the original images, even though the compressed images contain, on average, only 2 percent of the information in the originals.

"I want to emphasize that this study does not necessarily imply that compression always improves diagnosis," Lucier said. "It means that radiologists can spot and localize features as well or better than before. The technology filters out the noise, if you will. But so far, there is no question that these radiologists did diagnose better using the compressed images."

Lucier is optimistic that the technique might be applied to other forms of telemedicine as well, if certain modifications are made.

"There are many forms of medical diagnosis that require an image to be read by a specialist," he said. "If image compression is applied to other diagnostic situations, you won’t actually have to have that specialist on hand if you can get the equipment to the patient. But this is proof in principle that file compression, if done properly, can confer advantages to both patient and doctor."

This research was funded in part by the Office of Naval Research, whose Mathematical, Computer and Information Sciences Division supports research on motion and still-image analysis, processing and enhancement.

Writer: Chad Boutin, (765) 494-2081, cboutin@purdue.edu

Source: Bradley J. Lucier, (612) 625-5532 or (765) 494-1979, lucier@math.purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Chad Boutin | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Health and Medicine:

nachricht Vanishing capillaries
23.03.2017 | Technische Universität München

nachricht How prenatal maternal infections may affect genetic factors in Autism spectrum disorder
22.03.2017 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Inactivate vaccines faster and more effectively using electron beams

23.03.2017 | Life Sciences

New study maps space dust in 3-D

23.03.2017 | Physics and Astronomy

Tracing aromatic molecules in the early universe

23.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>