I read more on Medical Imaging. Today covered another familiar subject (also veering away from radiation): Ultrasound!
Ultrasound
We all know how bats get around: echolocation. They let loose super-high-pitched sounds, and wait for the echo to come back to their super-sensitive ears. They measure how long the sound took to echo back, and then figure out where the object that the sound bounced off is. According to the book, this is how they find bugs.
In the same way, doctors have been using a very similar technique to see inside the body. They use ultrasound (another name for super-high-pitched sound waves) probes to send ultrasound into the body. Ultrasound, despite being too high for humans to hear, is still vibrations and a type of sound. Ultrasound bounces off certain organs it can't pass through, like a fetus (still-developing and unborn baby), and comes back to the probe. A computer then measures the come-back times, does measurements and computing, and makes images. This was originally developed by a pair of Australian brothers, and, of course, has developed and upgraded over time.
The most common, and well-known version, of ultrasound use is to check the fetus in pregnant woman. A pregnant woman has an ultrasound scan at early development, and one later on. Sometimes, if it is what the book calls an "at risk pregnancy", which can be older woman, problems in the fetus whether genetic or otherwise, or more than one fetus, the woman has more. Ultrasound can also be used to check for cancers, fibiary (sp?) growths on ovaries (what it was used for at first before fetus-detecting was discovered), and checking the liquid the fetus is in (using a hollow needle in this procedure according to book). In fact, for the "growth-on-ovary" thing, a scientist working on ultrasound once used this to save a woman's life when other procedures couldn't detect the growth and helped pump up ultrasound in the medical world!
According to the book, the development of sonar (SOund Navigation and Ranging) and ultrasound flaw detector in WWII helped in the development of the ultrasound for medical purposes. A scientist figured he could use an adjusted ultrasound flaw detector, which used ultrasound to check for tears and stuff that could weaken metal vehicles according to the book, to check inside the body. Then came the "growth-on-ovary" incident described above. But people still weren't sure on ultrasound, since they didn't develop such great pictures back in the day. But the book says that it was discovered the using X-Rays on fetuses caused blood and other types of cancer, and then ultrasound became popular.
Ultrasound has gotten better, of course. The book says that they can now make 3D images, which comes into use in certain surgeries where the doctors put their tools through small cuts in the body ("keyhole" surgeries), and watch an ultrasound 3D image and work using that. Book mentions, however, that a lot more wires is needed to make a 3D ultrasound to a probe the same size as an old one which could make 2D images.
The book mentions that two Japanese scientists figured out a way to use the Doppler effect with ultrasound to see whether or not blood is flowing to or away from the probe. It goes to say that the Doppler affect is when the frequencies of a sound are heard differently if the sound-maker is going away from you or towards you (higher if towards, and lower if going away from). Then the book says the Doppler ultrasound sees if the echoes are higher than the first sound, meaning blood is flowing towards the probe, or if it's lower than the first sound, meaning it's flowing away. This can be used to diagnose many problems, like arteries hardening (in older people usually) or different heart (cardiac) problems or heart-valve (which control blood flow) problems, according to the book.
Ultrasound, with its modern 300x higher than highest frequency humans can hear sound releaser (sp?)(according to book), isn't just for checking stuff either. Ultrasound can be used for treatment as well! Ultrasound causes vibrations, which causes heat, and that can help join problems, according to the book. The book says that ultrasound treatment can help with kidney and bladder stone problems. Books says that these stones can be made in the kidney or bladder, and it's painful when they are passing through. But then the book says that ultrasound can shake these little stones apart, and then they can just go through the bloodstream.
Extra
Got some interesting animal facts from Magic School Bus yesterday, when the younger sibs were watching. We all know that animals live in cities when they're in zoos. But did you know that some animals (show uses racoons, foxes, opposums [sp?], and falcons [probably peregine]) live in the city and aren't in zoos?
What do they eat? A ton of stuff... primarily, our garbage! Talk about recycling! And there's a ton of hiding spots for them to use... the show used an old shed with a crack in it as an example. And buildings make great "cliffs" for falcons to perch on. And those birds eat other birds that fly through and have snacks in the city (show used some eating moths under light). And these animals are small enough to live in the city... bigger animals, like bears, not so much. Not only do they cause panic, they have to continually move in order to avoid people! Not enough time to survive in the end. The smaller animals, however, can have families in the city and live there. Some people now this already, in fact. Momma racoons are overprotective of their families, and do some nasty hisses if someone comes near during their active time--night (though show showed one eating worms from toppled pot during day)!
We all have heard of the sea anonome (sp?)/clown fish partnership. But many more exist... and a good deal in the coral reef! Some sea anonmes (sp?) have a partnership with hermit crabs! The plant's spines protect the crab when the crab puts it on its back (show used octopus as enemy/eater), and the plants get a free ride!
There's a partnership between Gobi fish and certain shrimp too in the coral reef. The shrimp are great diggers, but can't see well. The Gobi fish use the holes to hide, and repay the shrimp by warning them of danger. And, in the coral reef where it's an all-you-can-eat-buffet in a way, there's a lot. Sharks and remora (sp?) have a partnership too... remora (sp?) get a free ride like the sea anonome (sp?), and they eat little creatures that are annoying and "ichty" (show says) to the shark. And not all partnerships are win-win for both. A certain crab hides under a black spiny sea-plant to protect itself, but the plant gets nothing out of it.
But get this... the coral reef is a partnership! We know coral reefs are alive (mostly, some parts are skeletons of dead coral). Polops (sp?) make the coral reef, and certain algae stick onto them. Algae makes food, since they're plants, and the polops (sp?) give the algae a place to live. A safe one in the "Danger Zone" of the coral reef (not many fish live in deep sea since it has barely any food and not many hiding spots, but coral reefs give plenty of both).
Coral reefs can get sick, believe-it-or-not! When the water is polluted, polops (sp?) get rid of the algae. This can make the reef sick, and drain it of its color too (in show, copper was polluting water, believe it or not!). If the pollution is removed, the reef does have a chance, since the algae comes back too, but can take a ton of years (according to show).
Friday, November 30, 2012
Thursday, November 29, 2012
Medical Central: MRI
I read more on Medical Imaging. The subject went from radiation to magnetic. Today's subject is another familiar term: MRI--Magnetic Resonance Imaging--machines.
MRI
MRI came from NMR (Nuclear Magnetic Resonance), which chemists used to figure out which atoms made up a substance. Someone realized the potential for looking inside the human body, and began to develop the MRI. The first machine, made by Damadian (who went to an university in Brooklyn, New York) was impressive, but it took the work of many scientists to create a good MRI machine (especially one who figured out how to make the image using data and showed it using math).
MRI scanners started coming into use in the mid-1980's. They were expensive, but worth it. They can do something PET and CT Scanners can't... they can see tissues!
MRI works by detecting hydrogen. Since this is primarily in water, it tracks water in the body. The MRI uses radio waves and magnets (primary one makes magnetic field stronger than Earth's natural one!) to trigger hydrogen atoms into releasing their own magnetic signals. Now, the book says these are weak signals, but the MRI can pick them up. Thanks to the atoms surrounding the hydrogen atoms, the hydrogen atoms send out slightly-different signals (according to book), but a machine attached to the MRI figures out these signals and makes an image (according to book). Now, substances with little water--like primarily-calcium bones--don't come up as well. But a lot of stuff can be seen... especially stuff surrounding by bone and cartilage. In fact, it's great for finding tumors in the pituitary gland, right under the brain and surrounded by bone, according to the book.
The book also pops up an interesting fact... this machine was also used for checking out the brain at first! In fact, today, there's something called functional MRI... AKA fMRI. This is a way of studying the brain. Japanese scientists figured out that MRI could trace blood flow in the brain. Since when a section of the brain is working it needs energy and oxygen, and therefore the blood flow increases (according to the book), this was a good way to figure out which part of the brain did what while someone was doing something. Book says that the scientists first get a baseline in which the brain rests, and then they scan the patient while doing some simple task, and then subtract the baseline, and figure out which parts of the brain were active when doing the activity. Now, there are debates on whether or not this is effective (some of it is on technique use, reports, experiments, and the fact that the brain changes functions faster than a machine can make an image) according to the book, but it's still pretty cool to me!
Like other machines in modern times, MRI machines can now make 3D images. Using pits called voxels (according to book: "volume" and "pixels" combined), a 3D image can be made. A surgeon can play around with this image as much as he wants, cutting "slices", looking at something (like a tumor) from every angle, and whatever, according to the book. The book states that this increases the chances of a successful surgery.
Now, to people with pacemakers and the little metal nets that keep an artery open, MRI machines can be dangerous because of the high-powered magnetic field. The book even says that patients going through an MRI are usually stripped of magnetic objects first. The book says that scientists once even thought that the high-powered magnetic field made the MRI dangerous, though they are now considered safe (and safer than a PET or CT Scanner, since those use radiation, according to the book).
MRI
MRI came from NMR (Nuclear Magnetic Resonance), which chemists used to figure out which atoms made up a substance. Someone realized the potential for looking inside the human body, and began to develop the MRI. The first machine, made by Damadian (who went to an university in Brooklyn, New York) was impressive, but it took the work of many scientists to create a good MRI machine (especially one who figured out how to make the image using data and showed it using math).
MRI scanners started coming into use in the mid-1980's. They were expensive, but worth it. They can do something PET and CT Scanners can't... they can see tissues!
MRI works by detecting hydrogen. Since this is primarily in water, it tracks water in the body. The MRI uses radio waves and magnets (primary one makes magnetic field stronger than Earth's natural one!) to trigger hydrogen atoms into releasing their own magnetic signals. Now, the book says these are weak signals, but the MRI can pick them up. Thanks to the atoms surrounding the hydrogen atoms, the hydrogen atoms send out slightly-different signals (according to book), but a machine attached to the MRI figures out these signals and makes an image (according to book). Now, substances with little water--like primarily-calcium bones--don't come up as well. But a lot of stuff can be seen... especially stuff surrounding by bone and cartilage. In fact, it's great for finding tumors in the pituitary gland, right under the brain and surrounded by bone, according to the book.
The book also pops up an interesting fact... this machine was also used for checking out the brain at first! In fact, today, there's something called functional MRI... AKA fMRI. This is a way of studying the brain. Japanese scientists figured out that MRI could trace blood flow in the brain. Since when a section of the brain is working it needs energy and oxygen, and therefore the blood flow increases (according to the book), this was a good way to figure out which part of the brain did what while someone was doing something. Book says that the scientists first get a baseline in which the brain rests, and then they scan the patient while doing some simple task, and then subtract the baseline, and figure out which parts of the brain were active when doing the activity. Now, there are debates on whether or not this is effective (some of it is on technique use, reports, experiments, and the fact that the brain changes functions faster than a machine can make an image) according to the book, but it's still pretty cool to me!
Like other machines in modern times, MRI machines can now make 3D images. Using pits called voxels (according to book: "volume" and "pixels" combined), a 3D image can be made. A surgeon can play around with this image as much as he wants, cutting "slices", looking at something (like a tumor) from every angle, and whatever, according to the book. The book states that this increases the chances of a successful surgery.
Now, to people with pacemakers and the little metal nets that keep an artery open, MRI machines can be dangerous because of the high-powered magnetic field. The book even says that patients going through an MRI are usually stripped of magnetic objects first. The book says that scientists once even thought that the high-powered magnetic field made the MRI dangerous, though they are now considered safe (and safer than a PET or CT Scanner, since those use radiation, according to the book).
Monday, November 26, 2012
Medical Central: SPECT and PET Scanners
Today, read something on SPECT and PET scanners. These two are actually related to each other. Once became before the other, and they are similar in quite a few ways.
SPECT Scanners
Scientists have been looking for ways to use radioactive materials other than X-Rays to help them see inside the body. One year after X-Rays were discovered, radioactivity was discovered. Scientists figured out how to tag certain substances with radioactive materials that they made (like radioactive water or glucose; these made radioactive substances are called radioisotopes). Then they could use a Geiger Counter or a scanner to track the substance on its journey throughout the body.
Two scientists made the SPECT (Single Photon Emission Computed Tomography, according to the book) scanner. It traces the tagged materials throughout the body, and keeps an eye on it, mainly by detecting photons (very tiny traces/"packs" of light or energy or radioactivity) and making images from the photons released by the radioactively-tagged substance (according to the book). When using glucose (the body's main energy source, or "food") as a tagged material, areas that use a lot of energy--like growing and dividing cells--can be detected. Since tumors also use a lot of glucose while multiplying and growing their cells, SPECT scanners are good for spotting cancers. However, they do not make images of the body or inside it. Since they're relatively cheap, though, they're still highly commonly used.
PET Scanners
Years later, however, a scientist team in an university in St. Louis, Missouri, combined a couple of different technologies (CT Scanner included) to make a better version of the SPECT Scanner... the PET (Positron Emission Tomography) Scanner! The substance is tagged with a radioactive substance that emits particles called "positrons". However, this substance released two positrons at once... in opposite directions! While there was once a spiky-helmet device, now the person is put (a picture shows a person lying down, wearing a wired hair-net thing) into a tubular area. The scan work kind of like a CT Scanner... detectors pick up the released positrons and radioactivity, and then form an image. And it takes them from all angles too.
PET Scanners took a while to come out into the medical field. But even now, they're primarily used in research, not medical purposes. All though it is used to figure out different brain disorders in the medical field (one of the first patients was a 2-year-old named Ryan Peterson who had major problems in half of his brain, and only a PET Scanner could pick the problem up. He had major surgery, where the problem-half's outer "skin" was taken away, and was acting normal pretty soon! This happened in 1985), and some other stuff (like heart stuff & problems; and a PET Scanner is still highly useful for detecting tumors and their location), it is primarily used in research.
Now, there are some problems with using PET Scanners. To get the tagged substance inside the patients, the patients have to drink something with the tagged substance inside, and then the substance rides the bloodstream and blood cells... this and, the books says, just drinking the substance can make patients nervous (makes total sense! The same method is used for getting the substances inside patients for SPECT Scanners), since the material is radioactive (in fact, for a long time, people weren't sure if using radioisotopes were safe... once scientist only felt safe about figuring this out by using them on himself!!!). The radiation only lasts a short time, though. But this makes a problem for guys who use PET Scanners... the substance has to be made on-site or very close to the PET Scanner. Because of this, not every hospital or medical place has a PET Scanner.
Also, while glucose is the primary substance that's tagged, it's not always used. For checking out the heart and its problems, for example, a type of ammonia is used. The trip via the bloodstream through the heart doesn't affect the data sent by the substance, so that's what used. Glucose doesn't really help in this department, and doesn't get much data, so this other type of ammonia is used.
SPECT Scanners
Scientists have been looking for ways to use radioactive materials other than X-Rays to help them see inside the body. One year after X-Rays were discovered, radioactivity was discovered. Scientists figured out how to tag certain substances with radioactive materials that they made (like radioactive water or glucose; these made radioactive substances are called radioisotopes). Then they could use a Geiger Counter or a scanner to track the substance on its journey throughout the body.
Two scientists made the SPECT (Single Photon Emission Computed Tomography, according to the book) scanner. It traces the tagged materials throughout the body, and keeps an eye on it, mainly by detecting photons (very tiny traces/"packs" of light or energy or radioactivity) and making images from the photons released by the radioactively-tagged substance (according to the book). When using glucose (the body's main energy source, or "food") as a tagged material, areas that use a lot of energy--like growing and dividing cells--can be detected. Since tumors also use a lot of glucose while multiplying and growing their cells, SPECT scanners are good for spotting cancers. However, they do not make images of the body or inside it. Since they're relatively cheap, though, they're still highly commonly used.
PET Scanners
Years later, however, a scientist team in an university in St. Louis, Missouri, combined a couple of different technologies (CT Scanner included) to make a better version of the SPECT Scanner... the PET (Positron Emission Tomography) Scanner! The substance is tagged with a radioactive substance that emits particles called "positrons". However, this substance released two positrons at once... in opposite directions! While there was once a spiky-helmet device, now the person is put (a picture shows a person lying down, wearing a wired hair-net thing) into a tubular area. The scan work kind of like a CT Scanner... detectors pick up the released positrons and radioactivity, and then form an image. And it takes them from all angles too.
PET Scanners took a while to come out into the medical field. But even now, they're primarily used in research, not medical purposes. All though it is used to figure out different brain disorders in the medical field (one of the first patients was a 2-year-old named Ryan Peterson who had major problems in half of his brain, and only a PET Scanner could pick the problem up. He had major surgery, where the problem-half's outer "skin" was taken away, and was acting normal pretty soon! This happened in 1985), and some other stuff (like heart stuff & problems; and a PET Scanner is still highly useful for detecting tumors and their location), it is primarily used in research.
Now, there are some problems with using PET Scanners. To get the tagged substance inside the patients, the patients have to drink something with the tagged substance inside, and then the substance rides the bloodstream and blood cells... this and, the books says, just drinking the substance can make patients nervous (makes total sense! The same method is used for getting the substances inside patients for SPECT Scanners), since the material is radioactive (in fact, for a long time, people weren't sure if using radioisotopes were safe... once scientist only felt safe about figuring this out by using them on himself!!!). The radiation only lasts a short time, though. But this makes a problem for guys who use PET Scanners... the substance has to be made on-site or very close to the PET Scanner. Because of this, not every hospital or medical place has a PET Scanner.
Also, while glucose is the primary substance that's tagged, it's not always used. For checking out the heart and its problems, for example, a type of ammonia is used. The trip via the bloodstream through the heart doesn't affect the data sent by the substance, so that's what used. Glucose doesn't really help in this department, and doesn't get much data, so this other type of ammonia is used.
Sunday, November 25, 2012
Dinosaur Central: Triceratops
Today, the focus was once again on dinosaurs... I read a book on one of the infamous dinosaurs... the Triceratops!
Triceratops
Usually, when we're introduced to dinosaurs, the Triceratops comes up... it's also one of the ones most seen in movies and books about the ancient reptiles. We get to know them by their three horns on their faces. In fact, the name "triceratops" has the meaning of "three-horned face". Makes sense, doesn't it?
Triceratops are part of a group of dinos called ceratopsians. "Ceratopsian" means "Horned-Faced". There's about 30 different kinds of ceratopsians, each with an unique number of horn-faces, and their frills. Yes, even the triceratops has a bony frill. It's around its head's back. While there are similarities, ceratopsians are very different... a different ceratopsian, the styracosaurus, looks very different from the triceratops!
Styracosauruses (sp?) had a lot more horns. Most of these horns were around the edge of its frill, which has two large heart-shape-like humps with hollow "valleys" within and two small "wing-humps" near its eyes' position, and its nose-horn is smaller than the triceratops. Triceratops have round frills, their two big horns above its eyes, and it has a pretty big nose-horn. Their skin were probably different colors too, but since we only have artists' interpretations to go on and none of us were in prehistoric times, none of us know for sure.
Triceratops were the largest ceratopsian ever, with a length of 30 feet (9 meters) and a height of 10 feet (3 meters). Believe it or not, its head was a long as its body was high... 10 feet (3 meters)! It was also the heaviest ceratopsian, weighed around 5 tons (4.5 t)! Yikes!
Paleontologists believe that the brain wasn't big, however. They guess that the Triceratops' brain was only about the size of a human's fist. The book says that Triceratops didn't have very sharp senses or smarts. The book also says that paleontologists also believe that the Triceratops weren't fast, mainly because of its body shape and size. Not a concern for eating plants (Triceratops are herbivores), but Triceratops were often prey to the T-Rex. The book says that Triceratops probably fought back, but couldn't win against the T-Rex.
Triceratops live in the late Cretaceous (book says the Cretaceous was 89-65 million years ago). They had different kinds of dino-neighbors, like the T-Rex and ankylosaurus (one of the armored dinos according to the book). They lived in areas that the Rockies cut through today... the U.S. states of Wyoming, South Dakota, Montana, Colorado, and Canada's provinces of Saskatchewan and Alberta are listed in the book. The book says that the Rockies have a lot of sedimentary rock, which fossils are made of.
The book says scientists use fossils to figure out all they can about extinct animals by searching for clues in the fossils. Also, scientists use the geologic time system. This chops Earth-history into smaller bits.
Triceratops lived in heavily-forested areas. The books says that the climate was similar to modern tropical ones, and that the climate had been hot and humid, but was beginning to cool, and that North America's inner sea was beginning to dry up.
Triceratops
Usually, when we're introduced to dinosaurs, the Triceratops comes up... it's also one of the ones most seen in movies and books about the ancient reptiles. We get to know them by their three horns on their faces. In fact, the name "triceratops" has the meaning of "three-horned face". Makes sense, doesn't it?
Triceratops are part of a group of dinos called ceratopsians. "Ceratopsian" means "Horned-Faced". There's about 30 different kinds of ceratopsians, each with an unique number of horn-faces, and their frills. Yes, even the triceratops has a bony frill. It's around its head's back. While there are similarities, ceratopsians are very different... a different ceratopsian, the styracosaurus, looks very different from the triceratops!
Styracosauruses (sp?) had a lot more horns. Most of these horns were around the edge of its frill, which has two large heart-shape-like humps with hollow "valleys" within and two small "wing-humps" near its eyes' position, and its nose-horn is smaller than the triceratops. Triceratops have round frills, their two big horns above its eyes, and it has a pretty big nose-horn. Their skin were probably different colors too, but since we only have artists' interpretations to go on and none of us were in prehistoric times, none of us know for sure.
Triceratops were the largest ceratopsian ever, with a length of 30 feet (9 meters) and a height of 10 feet (3 meters). Believe it or not, its head was a long as its body was high... 10 feet (3 meters)! It was also the heaviest ceratopsian, weighed around 5 tons (4.5 t)! Yikes!
Paleontologists believe that the brain wasn't big, however. They guess that the Triceratops' brain was only about the size of a human's fist. The book says that Triceratops didn't have very sharp senses or smarts. The book also says that paleontologists also believe that the Triceratops weren't fast, mainly because of its body shape and size. Not a concern for eating plants (Triceratops are herbivores), but Triceratops were often prey to the T-Rex. The book says that Triceratops probably fought back, but couldn't win against the T-Rex.
Triceratops live in the late Cretaceous (book says the Cretaceous was 89-65 million years ago). They had different kinds of dino-neighbors, like the T-Rex and ankylosaurus (one of the armored dinos according to the book). They lived in areas that the Rockies cut through today... the U.S. states of Wyoming, South Dakota, Montana, Colorado, and Canada's provinces of Saskatchewan and Alberta are listed in the book. The book says that the Rockies have a lot of sedimentary rock, which fossils are made of.
The book says scientists use fossils to figure out all they can about extinct animals by searching for clues in the fossils. Also, scientists use the geologic time system. This chops Earth-history into smaller bits.
Triceratops lived in heavily-forested areas. The books says that the climate was similar to modern tropical ones, and that the climate had been hot and humid, but was beginning to cool, and that North America's inner sea was beginning to dry up.
Friday, November 23, 2012
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!).
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!).
Monday, November 19, 2012
Medical Central: X-Rays
I started this awesome book on different stuff doctors use to see inside our bodies. They use these scanners, which uses different waves and such, to actually see inside us! This process is called Medical Imaging, and it gives doctors an extra step in figuring out what's wrong with us. Without it, there are two other methods: listening to symptoms, and an examination that includes touching, looking at, and listening to our bodies. Since the problem is usually inside us, and many illnesses have similar symptoms, using only these two can be limiting and tricky for diagnostics (process of identifying what's wrong with the patient). But with Medical Imaging, things become easier.
And it started with X-Rays!
X-Rays
We all know X-Rays. When we've hurt our limbs, like a leg or arm, the docs have us get an X-Ray to see our bones and make sure nothing's broken. They are the most common scanner, and honestly the most well-known. They're relatively cheap to make, so doctors use a lot! There's a lot of types as well, like a X-Ray TV system which is an upgrade from flouroscopes (sp?) which made "movies" of real-time moving X-Rays images (made by Thomas Edison!). TV-X-Rays use similar techniques, but use an image enhancer to make the picture sequence better and put it on TV. And there's a process in where doctors inject certain chemicals into bloodstreams so that they can be seen on an X-Ray as well. In fact, the first CAT scan, used in a small London hospital when first time, used X-Rays to scan a woman's brain (the device that did this is called a CT, which stands for computed tomography, scanner).
X-Rays were discovered by a German scientist (who moved to the Netherlands when 3, and got an award for his X-Ray research). He was experimenting with a cathode tube (the type used in old-style TVs and the bulky computer monitors). That's basically a tube with the air vacuumed out and wires attached. Electricity causes certain energy to go from one end to the tube then to other other (negative end [cathode] to positive end [anthode][sp?]). This causes a glow, but the light doesn't go very far... only a few centimeters! But the scientist noticed a flourscent (sp?) material glowing in the dark room, and realized that a different radiation was emanating from the tube. He named this new radiation "X-Rays".
A bunch of experiments followed. Somehow, probably by accident, put his hand in the way while making a "photograph" (X-Rays cause special photographic material to darken, and less-hit areas lighten, making a photo), and the X-Rays couldn't go through his hand, so... Ta-da! (sp?) The first X-Ray image! He even did one later with his wife's hand... and the X-Rays couldn't even get past her ring!
Then he released his discovery to the public. Doctors soon realized how useful X-Rays could be to medicine, and a doctor use an X-Ray image only two months later!
X-Rays are part of the electromagnetic spectrum. Everything on the Electromagnetic spectrum travels at the speed of light, but they have different frequencies... AKA, different energy levels. Normal light that we see by is in the middle of the spectrum, microwaves and infrared are on the low-level end... and X-Rays are on the high-level bit.
This, of course, makes X-Rays dangerous. But few people realized that at first. Maybe people died from overexposure and the long-term affects (like cancer) of absorbing too much X-Ray radiation, including someone who worked with Edison! Some people realized the danger, but were ignored for a long time. X-Rays were even used for tiny things... some people had hand-scanners, and barber shops had "Foot-O-Scopes" which let people see their feet bones! Of course, people eventually realized the dangers. A detector was made for people who worked with X-Rays... a card with photographic material which got dark when too much radiation was absorbed (a similar detector is still used in modern times).
X-Rays got better with time, like anything. This may be hard to believe, but once upon a time, it took two hours of X-Ray absorbing to make a photo! This eventually got cut down to seconds, and even to where multiple pictures could be taken in a few seconds! And process to improve the picture (like moving metal grills to eliminate blurs and "snow" on the photo) were made.
In fact, in 2000, digital X-Rays popped up. Now electrical detectors, instead of photo material, could pick up X-Rays and send a code which explained how much hit them to a computer. The computer translated the code, made a photo, and then the photo could be stored on disks or wherever, looked at, sent to a different hospital to get a different doctor's opinion, and printed out! These X-Ray images could also be used for permanent records and whatnot. And there's no need for chemicals or darkrooms to develop the photo (since photo material was what used to be used, and had to be developed like normal photos, like what was made with non-digital cameras)! That's cool!
And it started with X-Rays!
X-Rays
We all know X-Rays. When we've hurt our limbs, like a leg or arm, the docs have us get an X-Ray to see our bones and make sure nothing's broken. They are the most common scanner, and honestly the most well-known. They're relatively cheap to make, so doctors use a lot! There's a lot of types as well, like a X-Ray TV system which is an upgrade from flouroscopes (sp?) which made "movies" of real-time moving X-Rays images (made by Thomas Edison!). TV-X-Rays use similar techniques, but use an image enhancer to make the picture sequence better and put it on TV. And there's a process in where doctors inject certain chemicals into bloodstreams so that they can be seen on an X-Ray as well. In fact, the first CAT scan, used in a small London hospital when first time, used X-Rays to scan a woman's brain (the device that did this is called a CT, which stands for computed tomography, scanner).
X-Rays were discovered by a German scientist (who moved to the Netherlands when 3, and got an award for his X-Ray research). He was experimenting with a cathode tube (the type used in old-style TVs and the bulky computer monitors). That's basically a tube with the air vacuumed out and wires attached. Electricity causes certain energy to go from one end to the tube then to other other (negative end [cathode] to positive end [anthode][sp?]). This causes a glow, but the light doesn't go very far... only a few centimeters! But the scientist noticed a flourscent (sp?) material glowing in the dark room, and realized that a different radiation was emanating from the tube. He named this new radiation "X-Rays".
A bunch of experiments followed. Somehow, probably by accident, put his hand in the way while making a "photograph" (X-Rays cause special photographic material to darken, and less-hit areas lighten, making a photo), and the X-Rays couldn't go through his hand, so... Ta-da! (sp?) The first X-Ray image! He even did one later with his wife's hand... and the X-Rays couldn't even get past her ring!
Then he released his discovery to the public. Doctors soon realized how useful X-Rays could be to medicine, and a doctor use an X-Ray image only two months later!
X-Rays are part of the electromagnetic spectrum. Everything on the Electromagnetic spectrum travels at the speed of light, but they have different frequencies... AKA, different energy levels. Normal light that we see by is in the middle of the spectrum, microwaves and infrared are on the low-level end... and X-Rays are on the high-level bit.
This, of course, makes X-Rays dangerous. But few people realized that at first. Maybe people died from overexposure and the long-term affects (like cancer) of absorbing too much X-Ray radiation, including someone who worked with Edison! Some people realized the danger, but were ignored for a long time. X-Rays were even used for tiny things... some people had hand-scanners, and barber shops had "Foot-O-Scopes" which let people see their feet bones! Of course, people eventually realized the dangers. A detector was made for people who worked with X-Rays... a card with photographic material which got dark when too much radiation was absorbed (a similar detector is still used in modern times).
X-Rays got better with time, like anything. This may be hard to believe, but once upon a time, it took two hours of X-Ray absorbing to make a photo! This eventually got cut down to seconds, and even to where multiple pictures could be taken in a few seconds! And process to improve the picture (like moving metal grills to eliminate blurs and "snow" on the photo) were made.
In fact, in 2000, digital X-Rays popped up. Now electrical detectors, instead of photo material, could pick up X-Rays and send a code which explained how much hit them to a computer. The computer translated the code, made a photo, and then the photo could be stored on disks or wherever, looked at, sent to a different hospital to get a different doctor's opinion, and printed out! These X-Ray images could also be used for permanent records and whatnot. And there's no need for chemicals or darkrooms to develop the photo (since photo material was what used to be used, and had to be developed like normal photos, like what was made with non-digital cameras)! That's cool!
Sunday, November 18, 2012
Dinosaur Central: Velociraptors
I got some cool data from a dinosaur book. While it did have some general dinosaur facts, the book's main focus was on Velociraptors.
Dinosaurs
The Age of Dinosaurs is known as the Mesozoic Era. It started around 228 million years ago, and ended 65 million years ago. Scientists think that a huge asteroid that hit the Gulf of Mexico is what ended the Mesozoic Era by kicking up a huge cloud of dust, which made the Earth cooler (which was normally a warm place, and the book says that extremes were only a few), which killed plants, which made herbivores (plant-eaters) starve, which made meat-eaters starve to death, since they had no prey. Now, some creatures like mice survived the disaster, but that's what scientists think what happened.
You may know this, but the Mesozoic Era is chomped up into three main sections. The first is the Triassic, whose late ages began 228 million years ago, and ended 206 million years ago, lasting about 42 million years. It was in these late stages that dinosaurs and the small mammals supposedly appeared. The other two is the Jurassic, going from 206-114 millions years ago, lasting 61 million years, and the Cretaceous, which went from 114-65 million years ago, lasting the longest of the three periods with 79 million years.
Dinosaurs supposedly ruled the Earth for 160 million years. But why? Scientists believe that this is because they were able to put their feet and legs directly under their body, giving them an advantage over other reptiles (yes, they were reptiles).
We all know dinosaur means "terrible lizard". But did you know it came from the word dinosauria, which was invented by an English dude named Richard Owen, who was indeed a scientist? The word is made from the Greek words deinos and sauros, which means "terrible lizard".
Scientists classify dinosaurs, of course. But they can chop all dinosaurs into two groups... by the shape of their hipbones! The ones with hips like modern birds are Ornithischians, which were all herbivores. This group includes Thryophorans (which include 4-legged stegosaurians like our friend the Stegosouarus), two other groups (which are ornithopods), which have dinos like Edmontosaurus and marginocephalians. The other hipbone group is the modern-lizard-like group: the Saurischians, which have theropods (which includes the most famous T-Rex, other 2-legged meat-eaters, and possibly have birds for a branch), and sauropods like the other famous dinosaur the Brachiousaurus.
Now, to the Velociraptors!
Velociraptors
I believe this was a great move, but the book clearly stated that the Raptors in the movie Jurassic Park were not Velociratpors. And there are a few pointers in that directions. Velociraptors, unlike the Jurassic Park Raptors, hunted by themselves and not in packs. Also, Jurassic Park takes place in a big jungle-like enviroment with plains, but scientists believe that Velociraptors lived in the desert... more specially, the Gobi Desert in Asia (part of which is China), where their fossils were found.
Velociraptors and Jurassic Park Raptors do share a few commons, though. Both of them have this big, special claw. Scientists aren't overly sure what the Velociraptors did with their crescent-shaped claw. It may have been for slashing throats or guts when hunting, or killing anything that got too close, or it may have helped the Velociraptor in grabbing a prey's back to pull it down and kill it.
Velociraptors weren't overly big. They were only about 6 ft (2 m) long, and weighed from 22-33 lbs (10-15 kg). This limited their hunting options... they hunted only small animals, like mice and shrew, and other small dinosaurs. In fact, there's an interesting story behind a fossil where a Velociraptor and a Protoceratops (Pig-sized dino with beak mouth and bony frill for a neck-guard that lived in same area as Velociraptors) are tangled. Scientists believe that the Velociraptor killed the Protoceratops, which fell on the Velociraptor. The Velociraptor was stuck, and basically starved to death. And then sand covered the two, and they ended up fossilized (which ended up in a museum).
Living in the desert makes things tricky too. Velociraptors have to be careful where they plop their eggs, since it has to be in the shade. And then animals who like shade and come out at night sometimes go after eggs. Speaking of living places, Velociraptors lived in the late Cretaceous.
It was once believed that all dinosaurs were cold-blooded. But Velociraptors are fast. This started scientists to believing that some dinosaurs--at least ones of the Velociraptor's family (Dromeosauride, which includes troodons) are warm-blooded! Part of the Velociraptor's speed is due to its hollow, lightweight bones. Sounds familiar? Members of the Dromeosauride family are similar to birds... scientists believe them to be cousins! Ever since the discovery of a Microraptor (cousin and closest relative to the Velociraptor) fossil with feathers, they even believe that Velociraptors and other similar creatures had feathers!
Dinosaurs
The Age of Dinosaurs is known as the Mesozoic Era. It started around 228 million years ago, and ended 65 million years ago. Scientists think that a huge asteroid that hit the Gulf of Mexico is what ended the Mesozoic Era by kicking up a huge cloud of dust, which made the Earth cooler (which was normally a warm place, and the book says that extremes were only a few), which killed plants, which made herbivores (plant-eaters) starve, which made meat-eaters starve to death, since they had no prey. Now, some creatures like mice survived the disaster, but that's what scientists think what happened.
You may know this, but the Mesozoic Era is chomped up into three main sections. The first is the Triassic, whose late ages began 228 million years ago, and ended 206 million years ago, lasting about 42 million years. It was in these late stages that dinosaurs and the small mammals supposedly appeared. The other two is the Jurassic, going from 206-114 millions years ago, lasting 61 million years, and the Cretaceous, which went from 114-65 million years ago, lasting the longest of the three periods with 79 million years.
Dinosaurs supposedly ruled the Earth for 160 million years. But why? Scientists believe that this is because they were able to put their feet and legs directly under their body, giving them an advantage over other reptiles (yes, they were reptiles).
We all know dinosaur means "terrible lizard". But did you know it came from the word dinosauria, which was invented by an English dude named Richard Owen, who was indeed a scientist? The word is made from the Greek words deinos and sauros, which means "terrible lizard".
Scientists classify dinosaurs, of course. But they can chop all dinosaurs into two groups... by the shape of their hipbones! The ones with hips like modern birds are Ornithischians, which were all herbivores. This group includes Thryophorans (which include 4-legged stegosaurians like our friend the Stegosouarus), two other groups (which are ornithopods), which have dinos like Edmontosaurus and marginocephalians. The other hipbone group is the modern-lizard-like group: the Saurischians, which have theropods (which includes the most famous T-Rex, other 2-legged meat-eaters, and possibly have birds for a branch), and sauropods like the other famous dinosaur the Brachiousaurus.
Now, to the Velociraptors!
Velociraptors
I believe this was a great move, but the book clearly stated that the Raptors in the movie Jurassic Park were not Velociratpors. And there are a few pointers in that directions. Velociraptors, unlike the Jurassic Park Raptors, hunted by themselves and not in packs. Also, Jurassic Park takes place in a big jungle-like enviroment with plains, but scientists believe that Velociraptors lived in the desert... more specially, the Gobi Desert in Asia (part of which is China), where their fossils were found.
Velociraptors and Jurassic Park Raptors do share a few commons, though. Both of them have this big, special claw. Scientists aren't overly sure what the Velociraptors did with their crescent-shaped claw. It may have been for slashing throats or guts when hunting, or killing anything that got too close, or it may have helped the Velociraptor in grabbing a prey's back to pull it down and kill it.
Velociraptors weren't overly big. They were only about 6 ft (2 m) long, and weighed from 22-33 lbs (10-15 kg). This limited their hunting options... they hunted only small animals, like mice and shrew, and other small dinosaurs. In fact, there's an interesting story behind a fossil where a Velociraptor and a Protoceratops (Pig-sized dino with beak mouth and bony frill for a neck-guard that lived in same area as Velociraptors) are tangled. Scientists believe that the Velociraptor killed the Protoceratops, which fell on the Velociraptor. The Velociraptor was stuck, and basically starved to death. And then sand covered the two, and they ended up fossilized (which ended up in a museum).
Living in the desert makes things tricky too. Velociraptors have to be careful where they plop their eggs, since it has to be in the shade. And then animals who like shade and come out at night sometimes go after eggs. Speaking of living places, Velociraptors lived in the late Cretaceous.
It was once believed that all dinosaurs were cold-blooded. But Velociraptors are fast. This started scientists to believing that some dinosaurs--at least ones of the Velociraptor's family (Dromeosauride, which includes troodons) are warm-blooded! Part of the Velociraptor's speed is due to its hollow, lightweight bones. Sounds familiar? Members of the Dromeosauride family are similar to birds... scientists believe them to be cousins! Ever since the discovery of a Microraptor (cousin and closest relative to the Velociraptor) fossil with feathers, they even believe that Velociraptors and other similar creatures had feathers!
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