Medical Central: CT Scanners

I read another chapter in that neat book about Medical Imaging equipment. The next subject sort-of came with the X-Ray subject... CT Scanners!

CT Scanners
First, something about X-Rays. Bones appear on the X-Ray photos because they absorb the X-Rays, keeping them from hitting and reacting with the detectors or photographic material. Skin, organs, and other soft body parts, don't... as much. More X-Rays pass through, and hit the detectors or photographic material. But they do absorb a little... there's usually a shadow of them in the X-Ray photo.
CT (computed tomography) Scanners use this fact to make their own images. They use X-Rays and detectors. X-Rays pass through the body, hit the detectors, and the computer uses information to make an image of a "slice" of the body. In fact, tomography means "a picture of a plane" in Greek, according to the book, which is basically what a "slice" is. This invention was developed by an English scientist by the name of Hounsfield in 1967.
At first, it took a long time to get enough data to construct a picture, and even for the computer to use that data to make the picture! The final image took days to get there.
But developments were made fast. Even just 10 years later, CT Scanners were making images in less than a second (and, according to the book, they're developing faster ones and those faster CT Scanners are to come, believe it or not). They were once black-and-white, but now the computer can now be told to add color. And it was once in 2D, but now computers can use CT Scanner information to make 3D images (there's a picture of one in the book, and it's hard not to believe that it was a drawing!). And the radiologist can tinker with this 3D image as much as her or she wants.
And CT Scanners were once used to just scan the brain, mainly for tumors (AKA, the main problem of cancer; this scan was usually used to determine the tumor's location before surgery), but now there are full-body scans. In fact, some people used to use full-body CT scans for their baseline medical records. But studies discovered that this is dangerous... while CT Scanners use relatively low dosages of X-Rays, a full-body scan causes the body to absorb a lot of X-Rays. X-Rays, especially in high dosages, are dangerous and can cause cancers. Not worth risking!
But CT Scanners are still highly useful. Especially in the chest and lungs area... they are great in figuring out problems in those areas. And, of course, they're still used to scan the brain for problems and cancer. And they're a big help in the emergency room... they can figure out the major problems right away in a ER patient going through a CT Scanner using this device.
Some of us know CT scans by the term "CAT Scans", especially at first. CAT stands for "computed axial tomography". But medical personal and places (like hospitals and such) now prefer the technical term of CT (Computed Tomography) Scans and CT Scanners (instead of CAT Scanners).

Extra
You know, Magic School Bus is an awesome show. My younger sibs were watching it, but I got a few electricity and smelling facts.
We know batteries store energy. But did you know that they push the energy (electricity) through their path (which is called a circuit?). The electricity goes around and round in a circular path (not always the same shape as "circular" indicates, but goes back to the start always), and if there's a break, everything comes to a complete halt! This even happens if there's no break in the path, but the battery is no good. If there's a light bulb filament along the way, the electricity powers up (by heating up) the filament, making it glow.
Of course, there's an on/off switch... usually. No-go if there's a break or useless battery anyway! And different stuff have different power levels. Flashlights (example in show) is safe, of course. But a lot of other house-hold items have dangerous power levels. The show wisely added a warning to be careful with bare wires and different electrical items, as well as no playing with them. And the electrical bits are positive and negative (they have no color, but the show added them for help) but they're called plus and minus to help determine which is which.
A fact we all know: we smell with our noses. But the question is... how? Things that give off a smell let loose smell molecules (which no one can see, since they're so small). Those molecules wander up our nose, and fit themselves into smell receptors built just for them. They go into certain spots like pieces in a jigsaw puzzle or a machine part in the machine (that's the best way I could describe those scenes). Then our brain is triggered to identify the smell. If our nose is stuffed up, those molecules can't reach and/or get into the receptors. And since our sense of smell is connected to our sense of taste... that little problem causes us to lose our sense of taste, or make things taste different.
Some things release more smell molecules than others, or some objects' smell molecules cause a bigger reaction from the receptors, making the smell stronger. But some things (example in show: rocks), don't release any smell molecules. But here's another curve-ball: some objects do release smell molecules but those don't trigger a reaction in our receptors (example in show: water. Yeah, water releases smell molecules! That's hard to believe, but true and awesome!).