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Guess that I was just too wound up. So, without further ado, I bring you Wednesday, 25APR2007, immediately followed with Thursday 26APR2007... then I will finish up todays' entry.

So, here we are, and you are probably wondering what I've been doing in Minneapolis, right? So I'll tell you.

Viital Images makes/licences software called Vitrea2; this software allows manipulating the volumetric pixels (voxels) that CT scanners and the like produce.

Probably everyone is familiar with Photoshop, which works with two-dimensional pixels... those on your screen right now. Vitrea works with three-dimensional voxels. In photoshop, each pixel is composed of a pixel and a color; voxels are three-dimensional cubes with a fourth quality, density.

We describe this density in Houndsville units, or HU; named after the guy who came up with the concept, I assume. Air has the least density, and bone the densest, at least in the human body; metal over a certain thickness depending on the type of metal, has an infinite density, sense it can't be penetrated with x-rays.

The main use of x-rays is to discover different densities in the body for medical diagnosis; x-rays are only minimally useful for this, being only two-dimensional, and not really all that sensitive..

CT scans, however, are very sensitive, and will even let you measure the HU of any structure. Add to this the ability to inject IV contrast material, and you suddenly have the ability to delineate vascular structures... just what the surgeon needs.

But, until recently, a direct arterial puncture was a necessity; CT machines weren't fast enough, but 35mm film in a camera, or cut film in a rapid changer would accurately visualize structures for the open-heart surgeon and the general vascular surgeon.

And the, about seven years ago, the MDCT (multi-detector CT) came into being. We got a four-slice scanner in 1999.

And now we have a 16-slice and a 64-slice scanner... and the 64 can do cardiac studies quite well.

There are 128- and 256-slice scanners in development by several manufacturers. They can visualize the entire heart in one heartbeat/rotation, or, in the case of stroke patients, the whole head. The latter isn't really practical just yet,. for reasons that I won't go into right now.

The goal of cardiac CT is to produce images that are just as good as a heart cath would, only it's minimally invasive, requiring only an IV injection.

And, with the Vitrea2 software, it is possible to do all of that and more.

With a good exam, we can study each of the heart vessels, measure them for stenoses, figger out the ejection fraction of the ventricles and estimate the condition of stents and grafts.

All of this, of course, requires a great deal of knowledge from the person running the system. They not only have to know the heart anatomy and physiology but they have to know how to run a very complicated piece of software.

And if you've use Photoshop, you are aware of how many options there are... and then you add in a third dimension.

So there you have the short story... I will be quite happy to expand upon request, or to answer any questions... just e-mail me.

Karen only slept fourteen hours... she told me that she went to bed around 21:00 and got up at noon, then she went back to sellp about 15:30 or so and didn't get up until 19:00. This chemo is knocking her on her ass, I'm afraid.

Back to the trip... when I was going up, I was having a lot of trouble with the iPod; it kepy jiggling out of the power outlet, which is on the dash. I had figgered out how to hook up the stretch-cord, but I hadn't put it together, and on the way up I just didn't want to mess with it, since it was raining cats and sometimes dogs and guppies... but I was getting PBS almost all of the way up there, kinda suprised me.

But I took the time to put it together coming back... and I love it! I had forgotten that I have so much good music, I guess. It made the ride back home much more fun.

I'm hoping to get turned back around by going to bed pretty early tonight and setting the alarm for the morning... now if I can only get to sleep.