MRI Technology May Aid Diagnosis

[justashell]

article from our local paper, Saturday, Oct. 21, 2006

 

 

MRI technology may aid diagnosis

by Betsy Mason

Contra Costa Times

 

Berkeley, Calif.---The MRI machine that most doctors use to get three-dimensional images of everything from strained knee ligaments to ovarian cysts could become 10,000 times more sensitive with a xenon gas technique devised at Lawrence Berkeley Lagoratory.

 

The advancement would allow doctors to track biological processes at the molecular level and could be extremely useful for diagnosing early stages of cancer or heart disease.

 

"If it works as well as we hope it will, it will be a singificant advance in cancer detection," said chemist David Wemmer, a member of the team at Bereley Lab and the Universtity of California, Berkeley, that developed the imaging technique.

 

Their findings were published Friday in the journal Science.

 

Wemmer and his colleagues found a way to use xenon atoms to highligh specific types of molecules, such as the proteins on the outside of cancer cells, in very low concentrations.

 

Conventional magnetic resonance imaging, or MRI, isn't sensitive to see cancerous cells until a fair amount of them have accumulated. The xenon amplifies the signal of these cells, allowing them to be seen more easily.

 

"The key to really diagnosing disease earlier and earlier is to start to look at hte differences int he molecular expression that's taking place," said atomic physicist Bastiaan Driehuys at Duke University Medical Center. "It's thought that we'll see things earlier and we'll be much more sensitive than if you wait until there's some functional or anatomical consequence of these molecular processes."

 

The xenon technique can also image several different types of molecules at the same time, which is also very beneficial for diagnosing specific types of cancer.

 

"The best analogy is if you were able to look with your eye, it would be the equivelant of having several different colors," Wemmer said. "With conventional magnetic resonance imaging that's already used widely for cancer detection, there's no way of making multiple colors. Even if you can tell a tissue is cancerous, sometimes there are many different types of cancer in the same organ."

 

Because different types of cancer respond better to different treatments, knowing the specific cancer type would help doctors choose the most effective treatment for a patient.

 

Wemmer and his team have only tested their methiod on a model system made of water and beads that mimic human tissue, but have hope the results will work in people some day.

 

They created synthetic molecular cages that have a special linking device on their shells that bind to specific molecules in the body, such as the proteins characteristic of cancer cells.

 

The patient would be injected with molecular cages designed to catch whatever type of molecule needs to be found, and then would inhale xenon gas before entering the MRI machine.

 

Xenon atoms---which flow early in and out of the cages---can be "hyperpolarized" by hitting them with polarized light. This makes xenon very easy for MRI machines to detect.

 

The trick is that the cages turn off the xenon atom's signal, leaving a dark spot in the middle of all the other xenon atoms that are lit up and giving away the presence of cancerous cells.

 

 

End Of Story

 

Hmmmm... I wonder if this is a development that would help with pit. tumors?