GARSCHING, Germany – If a laser beam was shot into the body, could this light source produce sound waves strong enough to be detected by an ultrasound transducer?

Or why not try carbon 13 as safer biomarker for molecular diagnostics using magnetic resonance imaging instead of the near-toxic contrast agents necessary for the radiation in computed tomography (CT)?

And can the radiation of CT be further reduced by reversing the geometry and using scattered multiple sources but at a lower aggregate dosage?

These questions, and many more like them, are at the heart of advanced healthcare imaging research being conducted across the network of General Electric's (Fairfield, Connecticut) four Global Research Centers (GRC).

Healthcare is one of six different focus areas for research for the diverse activities of the conglomerate that also covers major business units for power transmission, energy, or lighting.

The European research center, located on the campus of the Technical University of Munich, is the newest and the smallest center in the network, but in a sense it is also the most pure, as all of the 130 scientists and engineers are focused on fundamental research.

By comparison, the massive John F. Welch Technology Center in Bangalore, India, has 3,000 technicians and scientists, more than 90% of whom are tied to specific product applications aimed for upcoming markets release, leaving about 300 employed in advanced research.

The structure of the Shanghai GRC, which opened just ahead of the Munich center, is similar with a workforce of 2,000 and 10% focused on fundamental research.

"It is not that we never work on urgent problems that may arise in the field, but as a rule what we do today you are not likely to find in a product for another 10 years," said Carlo H rtel, managing director of the Munich center.

"Though there may have been an announcement recently that holographic data storage may be hitting the market by 2012," he said pensively.

The six labs at the center that H rtel oversees, including healthcare imaging, pursue a special class of advanced projects, he said, "to test technologies, even potential technologies, that still need to be proven before we take a shot at an application."

Still, it would not be true to the GE culture if a commercial angle was not visible on the horizon, not matter how distant.

The GRCs receive 25% of their funding from a combination of a patient corporate headquarters and then external financing from government programs encouraging innovation.

The European center, for example, participates in shared research projects funded by Germany, Bavaria or the European Union Framework Seven program.

But the centers are overwhelmingly dependent on specific GE business units for 75% of their funding.

The Advanced Medical Applications lab is managed by Theodore Vetter, who said that while there are fundamental research activities being pursued for ultrasound, such as the laser provoking sound waves, and traditional X-ray, such as detecting chemical composition of liquids using dual energy sources, the Munich center leans heavily toward magnetic resonance imaging.

Just walking up to the building on the university campus gives a hint of the importance of MRI here as visitors with pacemakers are directed to an entrance away from the wing where the imaging research lab is located.

The carbon 13 (C-13) project is actually moving along nicely, according to Vetter, as it has moved from the chalkboard to pre-clinical animal studies.

The scientists asked what would happen if the rare substance C-13, which is magnetically excitable and produces vividly sharper views for MRI, were injected into the body.

Since the human body is based on carbon 12, the open question is whether C-13 would do any harm if it was injected into a patient undergoing an MRI scan.

But how much do you excite the C-13 liquid? And how long does that polarity last in vivo? And what is the right dosage? And will the C-13 flow naturally as a substitute into ongoing human metabolic processes, like a growing tumor?

Beyond the bio-mechanical issues, there are the complex sequencing computations that are at the heart of interpreting MR signals into images and are a specialty of scientists at the European center.

A doctor's request for even a routine MRI is translated by the radiologist into a series of sequences to produce typically three types of images of the targeted region.

Each image request has a precise set of pulse sequences that if done in one manner will produce, for example, white-based images of cerebral spinal fluid while brain matter is toward the black scale. There is a sequence to do the opposite, as well.

Specialized pulse sequence variations are designed to depict details in the body for vessels, or muscles or tumors, said Vetter.

He said the use of C-13 will open a new area of challenges for sequence design to maximize the images possible once a body is infused with such an MRI-friendly agent.

The increased use of combined positron emission tomography (PET) with CT for full body scans stimulated another challenge to the medical imaging group that asked if it is possible to substitute non-ionizing radiation of MRI for CT and thereby eliminate the risk of radiation for patients while achieving faster acquisition times.

While MRI is not yet capable of producing the kinds of stunning resolution that CT has achieved, according to Vetter, the GRC network is working on the problem, building new radio frequency (RF) coil arrays for parallel and rapid acquisition of images.

This work can best be compared to traditional photography, he said.

Conventional MRI uses a single source for RF excitation of the magnetic field, comparable to the results of using a single floodlight for a photo shoot he said.

Distributing the RF in arrays of eight to 16 or even as high as 64 coils produces the equivalent of a balanced, even lighting in photography.

Along with the new technology comes new challenges for sequencing that promises to keep the Munich team busy for some time.