It Might Get Messy

It Might Get Messy

Technology…you can’t live with it…no, that’s not right. You can’t live withOUT it. Whatever your feelings about Bill Gates, automakers, music listening devices, or whichever hellishly sluggish wireless internet service you’re living with, it’s a shitload better now than it was 10 years. And WAY better than it was 35 years ago.

Because in 1977, nuclear magnetic resonance technology was engineered for noninvasive, high-resolution imaging of living human tissue. Magnetic Resonance Imaging (MRI) is a very sensitive—subatomic, if it comes right down to it—technique for ascertaining…uh, imaging…the surface structures of stuff.

It works like this. You whip up one bad-ass massive magnetic field and stick a chunk of matter in that field, then the directional “spins” of the protons and neutrons in the atomic nuclei of the stuff your chunk is built from all line up nicely in a uniform plane. But not direction. The spins may run “frontward” or “backward”, but the thing is they don’t run at angles or “awkward”. Oddly (or maybe it’s not odd, I flunked chemistry twice and almost flunked physics twice, so I may not be the best person to ask), just about 50% of the atoms spin “front” and 50% spin “back”. Basically, when you are the chunk of matter in the magnetic field, the nuclear particles spin toward your head or your feet, but not toward your hands or your butt. But the symmetry is not exact. A few atoms out of each million don’t pair up with a converse-spinning doppelganger.

Those asymmetric or unpaired atoms are important to what happens next. You run a pulse of radioenergy into the field, guided by some additional “gradient” magnets. The unpaired atoms respond to the radioenergy in a distinctive fashion depending on their atomic bonds (i.e. electron-to-electron-to-nucleus, thus MRI uses NMR technology but is not limited to “nuclear” signals), that is, their structural properties. The edges of things—organs, cells, tumors—have discernibly distinct structures. By converting the return energy of the radio-perturbed magnetic field to pixels for imaging, well voila! A high-rez look at anything you care to look at!

By comparison, the Positron Emission Tomography (with the radiolabeled glucose) we looked at last week has spatial resolution—detection of the atomic decay—at centimeter scales. With the MRI, you’re looking at submillimeter scales. So it’s the MRI that surgeons use to localize, characterize, and size up a tumor.

I’m not a surgeon (as the Bitchin’ Kitchen lady would put it on Food Network, “it ain’t rocket surgery”). Nor am I trained in use of the awesome software that comes with the set of digital images from the radiology shop these days. So I’m not going to be able to show you the marvelous detail and full certainty of what’s going on in the MR images. I will try to get Dr. H to look at the slices I’ve picked out and see if I’ve got the right concept. Because here’s the thing:

I’m pretty sure that ragged edge on the northeast of my tongue there, and the dark splodge on the southeast are evidence of the “old” tumor—the one we took care of last year. My tongue is ragged because… well, my tongue is ragged. Radiation and chemotherapeutics killed the tumor tissue, which eventually rotted out and fell away, leaving raggedy edges on things.

And here’s my present difficulty. See that little bean-like nugget down there near the center and base of my tongue? That’s on the right side, if I’m reading the imaging “slices” correctly. And it’s where I’ve been having pain. And, more ominously, where that white-hot spot of radioactivity was in the PET scan a couple weeks ago.

When we congratulated ourselves last year at kicking my cancer’s ass, we did so in the face of the close-out PET scan report that mentioned sort of spraddled out but metabolically hot tissue on the right side tongue base. At that time, all the docs agreed it was an artifact of radiation damage. The sugar uptake was in inflamed tissues still healing.

I wasn’t quite so sanguine, but understood their point. The residual metabolically active tissue was right where the most intense collateral damage from the radiation would hit, and didn’t look like a coherent tumor.

That was then. Tomorrow I go to my GP’s shop for pre-surgery checkouts. On Friday I go to the hospital early for nine o’clock surgery to biopsy that nugget on my tongue. I’ll keep you appraised. Oh, and remind me to tell you about “contrast” materials in MR imaging sometime…. .