Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Advanced image analysis can provide better risk assessment in hardening of the arteries

08.06.2009
Ultrasound examination of the carotid artery is a patient-friendly and inexpensive method for assessing atherosclerosis and thereby predicting the risk of cardiovascular diseases.

Peter Holdfeldt, who recently defended his doctoral thesis at Chalmers University of Technology in Sweden, has developed new analytical methods for ultrasound images that can provide more reliable and more exact assessments of atherosclerosis.

Cardiovascular diseases brought on by hardening of the arteries are the most common cause of death in the Western world. Hardening of the arteries means a thickening of the walls of blood vessels and the appearance of so-called atherosclerotic plaque, which consist of stored fat, among other things.

With the aid of ultrasound images, it is possible to find individuals who are at risk by measuring the thickness of the walls in the carotid artery. Another ultrasound method is to analyze whether the character of various types of plaque can predict the risk of cardiovascular diseases.

Peter Holdfeldt has developed new and more refined methods of image analysis that are based on dynamic programming.

"Measurements of the thickness of the walls of the carotid require the detection of boundaries between different layers of tissue in the blood vessel," he says. "Previously dynamic programming has been used to automatically detect boundaries in still images. But the new method uses dynamic programming for detection in image sequences of one and the same blood vessel instead."

Examining an entire image sequence instead of a single image provides a more correct result, since it is possible to make use of the similarity between the images in the sequence - a boundary ought to be found in roughly the same place in two images in a row. The method comprises two steps. First, several alternative locations of the boundary are determined in each image. Then one of the alternatives is selected from each image, and it is in this step that the program factors in the movement of boundaries between images.

"This has proven to provide more correct detections of boundaries than what you can get from a program that detects boundaries on the basis of a single image," says Peter Holdfeldt.

He has also developed a method to automatically classify atherosclerotic plaque. This plaque can burst and form blood clots that cause heart attacks or strokes. In ultrasound images it is possible with the naked eye to see the type of plaque that often leads to stroke, but such an assessment is subjective and is influenced by disturbances in the image. The new automatic method entails a technological advancement of ultrasound technology that can lead to more objective and quantifiable analysis.

Peter Holdfeldt's research has been part of a collaborative project between Chalmers and the Wallenberg Laboratory for Cardiovascular Research at Sahlgrenska University Hospital in Gothenburg. Björn Fagerberg, a physician and professor of cardiovascular research, is responsible for the clinical evaluation of the new methods together with the doctoral candidate Ulrica Prahl.

"We're now busy testing the new automatic method for plaque classification in patient groups," he says. "In its final form it should be an excellent aid in identifying high-risk patients."

Measurement of the carotid artery is already in use today in cardiovascular research. There are other methods of measurement, but they are not as well validated as the method that has been developed by the researchers at Chalmers and Sahlgrenska.

"Dynamic image analysis is an exciting new method that will no doubt offer great potential for elaboration," says Björn Fagerberg. "The advantage of using ultrasound is that is practical, inexpensive, and patient-friendly."

The dissertation "Dynamic Programming for Ultrasound Image Analysis of Atherosclerosis" was defended on May 15.

Peter Holdfeldt, Department of Signals and Systems, Chalmers University of Technology

hfeldt@chalmers.se

Björn Fagerberg, Wallenberg Laboratory at Sahlgrenska University Hospital
Phone: +46 (0)31-3428382; cell phone: +46 (0)706-883387;
bjorn.fagerberg@wlab.gu.se

Sofie Hebrand | idw
Further information:
http://publications.lib.chalmers.se/cpl/record/index.xsql?pubid=92553
http://www.chalmers.se/s2/EN/research/divisions/medical-engineering

More articles from Medical Engineering:

nachricht Penn first in world to treat patient with new radiation technology
22.09.2017 | University of Pennsylvania School of Medicine

nachricht Skin patch dissolves 'love handles' in mice
18.09.2017 | Columbia University Medical Center

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Bacterial Nanosized Speargun Works Like a Power Drill

26.09.2017 | Life Sciences

The fastest light-driven current source

26.09.2017 | Physics and Astronomy

Beer can lift your spirits

26.09.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>