Non-Intrusive 3D View of Subcutaneous Tumors

Chris writes: "A holographic imaging system gives the first visual "fly-through" of living tumors just under the skin. David Nolte and colleagues from Purdue University, US, have developed an optical imaging system that allows clinicians to "fly-through" near-surface tumors in real time. In the scheme, a laser fires 100 fs probe pulses into the skin. The pulses weakly reflect from varying depths below the surface and are compared to a coherent reference pulse which, thanks to a time-of-flight measurement, originates from a known depth. A hologram then rejects unwanted, incoherent light leaving only the useful, image-bearing signal. Only a fraction of a nanowatt of optical power is required to write the hologram. A joystick controlling the depth of the reference pulse allows the clinician to explore the tumor. For example, to probe deeper into the tumor, the clinician simply pushes the joystick forward. The reflected pulses are then compared to this new reference and new depth information is written onto the hologram."

According to my notes: very short range

[Yarn]

This optical coherence method (OCT) has been used to examine retinal defects for about 5 years now.

In the eye it has the benefit of a nearly clear path to the tissue being analysed. 100micron resolution is commonly acheived.

On the skin the depth that can be analysed is less than a millimeter, so this is really only of use for skin cancers.

There are far more exciting systems in development, which allow deeper investigation (at the cost of resolution alas) and can also determine tissue type by florescence spectra.

Compare that with this method...

[morcheeba]

U of Texas [utexas.edu] has done this chemically using glycerol to dry out tissues. Most impressive are the pictures [utexas.edu]. The story is a bit dated, but at the time, they had only done this with hamsters. previous slashdot story [slashdot.org]

Great -- another way for doctors to kill people

[jonman_d]

I don't know about you, but the growing trend seems to be "hospitals kill people, not save them." I live very close to Stonybrook Hospital (think that's the name, not quite positive), which just recently killed a new-born. Incorrect dosage of medicine, I believe it was. Apparently, the entire system is shot - the probably started at the top of the chain, and worked its way down to the nurses, and nobody ever caught it.

IMHO, before we start to implement more technology that requires more training, we need to fix what's already wrong with the system. I understand that this will save lives, but technology is only as good as the hands that it's in.

Re:Great -- another way for doctors to kill people

[quantaman]

On the contrary that trend is infact lessening, as we learn more about medicine there is less snake oil and more curse that help people instead of harm them. The difference is now we have the experience, and a little more honesty which allows us to find out that that baby died of an incorrect dosage as opposed to 50 years ago when they might of attributed to some illness due to ignorance or just a plain cover up. I agree that training is crutial, moreso than the equipment, yet I still believe that overall the world health care is as good as it's been (I don't know about the US in particular but Canada is on a bit of a downhill now due to cutbacks).

New Methods

[ClimberTech]

What's the point of having such an accurate view of the tumors? Shouldn't we be focusing on ways to either prevent or destroy them, rather than observe them?