Getting a clearer picture of the inside

Scientists at the Mater Hospital and Dublin City University are seeking to develop image processing and software visualisation…

Scientists at the Mater Hospital and Dublin City University are seeking to develop image processing and software visualisation tools to improve the accuracy of medical imaging in the digestive tract.

The project takes computer expertise and merges it with medical skills to come up with a blend of the two. The imaging tool would be used to study the biliary tree, a passageway through which bile is transported from the liver to the bowel.

This part of the body can be imaged in a few seconds using magnetic resonance imaging (MRI), explains Dr John Stack, chairman of the division of radiology at the Mater Hospital. The biliary tree, however, is a difficult region to evaluate. "It is in an awkward position in the body and is a very busy area," says Dr Stack.

The most serious problems are obstructions of the passageway. If stones, formed for example in the gall bladder, a reservoir for bile, are pushed into the biliary tree and get stuck, the person can be in "real trouble", says Dr Stack. The bile backs up, leading to infection and severe abdominal pain - a life-threatening condition. Tumours can also grow in the biliary tree, and these, too, can obstruct the flow of bile.

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The new research is being carried out by DCU's vision systems laboratory and the Mater's department of radiology and is funded by both institutions. "It will be another two years before the technology can be used on a day-to-day basis," says Dr Whelan, director of DCU's vision systems laboratory. "Hopefully at that stage it can be used on a prototype basis."

Another project under way at the vision systems laboratory is looking at enhancing medical images of different parts of the body, including the heart and colon, says Prof Whelan.

As well as sharpening the images of the biliary tree, they can also be manipulated to enable analysis with two- or three-dimensional images, depending on the needs and experience of the viewer, he says.

Radiographers, for example, are used to looking at two-dimensional images. But surgeons, during operations, view the organs in three dimensions. The software could present both views, he says.

An alternative way of viewing the MRI images could provide more information from which radiographers and radiologists could make diagnoses. Dr Stack says the project aims not to change how the data is acquired but how it is analysed.

Prof Whelan stresses that the work does not try to automate the work of radiologists, but will give them a better diagnostic tool.

It could also be a used as a teaching aid, adds Dr Stack.

This project started a year ago. Dr Stack says there is "great co-operation" between the two groups of researchers. Four people are involved in the project in the Mater, and soon there will be six people working in DCU on medical imaging projects.

The creation of sharper, information-filled images is the latest in a line of developments in medical imaging.

Before MRI, the biliary tree was viewed using a procedure called ERCP.

This involved passing an endoscope through the mouth into the duodenum and inserting a small catheter into the biliary tree. A dye was then injected directly and radiographs were able to "see" the anatomical layout of the biliary system.

This highly invasive method is "falling out of favour" with the arrival of MRI. The patient also has to be sedated, the dye causes acute pancreatitis in 2 per cent of patients, and the procedure is time-consuming and very skilled and involves a short hospital stay.

The new technique would be sophisticated but not invasive, and scanning and reading would be done outside the body.