Download Diagnostics

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Radiation burn wikipedia, lookup

Radiation therapy wikipedia, lookup

History of radiation therapy wikipedia, lookup

Positron emission tomography wikipedia, lookup

Center for Radiological Research wikipedia, lookup

Radiosurgery wikipedia, lookup

Industrial radiography wikipedia, lookup

Medical imaging wikipedia, lookup

Image-guided radiation therapy wikipedia, lookup

Backscatter X-ray wikipedia, lookup

Nuclear medicine wikipedia, lookup

Mammography wikipedia, lookup

X-ray wikipedia, lookup

Fluoroscopy wikipedia, lookup

Transcript
Carlan Samuelson
Physics 1010
Diagnostics
x-radiation, Ultrasound, Mammography, Nuclear Medicine & MRI
X Radiation, also known as X-ray was discovered in 1895 by Wilhelm Conrad Roentgen
who died away in 1923. Roentgen was a professor at Wuerzburg University in Germany.
Roentgen had discovered a scientific bombshell when he had a cathode-ray tube in his
laboratory where he observed a fluorescent glow of crystals where his tube was laying. He was
working with a bulb of positive and negative electrodes which were encapsulated in the bulb
and discovered a bright colored light created by the material located near the tube. He was able
to shield the tube with heavy black paper, and found a green colored fluorescent light
generated by a material located only a few feet away. Through additional experiments, he also
found that a new ray would pass through most substances. He named the ray X-ray, because, in
mathematics “X” is used to indicated the unknown quantity.
Later this invisible ray was found to pass through solid matter, such as X-rays would pass
through the tissue of humans leaving the bones and material visible. One of Roentgen’s first
experiments in 1895 was a test on his wife Bertha’s hand with a ring on her finger.
This news of his new x-ray spread quickly throughout the
world and became very public, and scientific fancy. Scientists everywhere would dublicate his
experiment because the cathode tube was very well known in early 1896. There was then
concern of potential danger, but not enough experiment was performed to suggest that X-rays
would in any way be hazardous. What it seemed to some, X-rays could be beneficial for the
body.
X-ray is just as ordinary as any other electromagnetic radiation. They are produced by
photons which is bits of energy used in light. There are two types of atomic processes that can
make x-ray photons. One, being the Bremsstrahlung, which is a German term for “braking
radiation”, and the second one being, K-shell emission. Both which are related in tungsten,
tungsten, a material to target anode of the x-ray tube. X-rays are made by the change of
electrons. However, Bremsstrahlung is a much easier and understandable process when the
velocity of the electron is changed. Bremsstrahlung Radiation are x-ray tubes producing
photons by accelerating a stream of electrons to energies which collides them into a heavy
material. So much acceleration of the electrons produces Bremsstrahlung photons. These
energy target materials are typically called tungsten. In the process of K-shell Emission
Radiation, you have to remember that atoms have their electrons arranged in closed “shells” of
different energies, therefor, the K-shell is the lowest energy being built out of an atom. Atoms
normally produce heat so the amount of K-shell used in atoms is about 0.1% of electrons. When
outer shell electrons drop into inner shells, they emit a “characteristic” part of an element
which is known as a quantized photon.
The Staff involved in X-ray tests and treatments are Radiologists. A Radiologist is a
doctor who is concerned with interpreting X-ray pictures and performing certain types of
investigations in the treatment or disease using x-rays. Cancer is one of the most commonly
treated using Radiation. A simple x-ray is extremely informative. It can show broken bones, and
problems with soft tissue in the body. During an x-ray examination the patient is asked to keep
still as possible for the few seconds it takes for each image to be obtained. It’s a painless
procedure with zero side effects. Immediately after the pictures are taken, the technicians look
over then and then send them off to the radiologist for further examinations. It is said that
radiation is dangerous and can cause cancer as well as treat it. That is so, except with the small
doses of radiation in such high quality x-ray images, the risk of cancer is very small; so small that
it shouldn’t be a scarce to any patient. Although, radiation can cause damage to a fetus, so any
women who suspects she is pregnant and is going in for an x-ray should make sure her doctors
know about her condition. In today’s society, x-rays are now also used in Dentist offices, where
they are used to observe teeth and jaws, also we use satellites with x-ray detectors on them to
do x-ray astronomy.
Ultrasound is energy generated by sound waves of 20,000
or more vibrations per second. Ultrasound is used for medical diagnostics, and uses sound
waves that are far above the frequency heard by the human ear. The history of ultrasound goes
back to Lazzaro Spallanzani. In 1790 he experimented with bats and found that they
maneuvered through the air using their hearing rather than sight. Later in the 1930’s, Dr. Karl
Dussik and Australian psychiatrist, published the first paper on ultrasound where he attempted
using his pictures to diagnose brain tumors. The procedure was called “hyperphonography”. He
used heat sensitive paper to record echoes. Ultrasound imaging then got it’s start.
Ultrasound imaging, is also known as ultrasound scanning or sonography, where it is
exposing part of the body to high-frequency sound waves to produce pictures of the inside of
the body. Ultrasound does not use ionizing radiation (as used in x-ray) because ultrasound is in
the NOW, and can show structures moving and internal organs, as well as blood flowing
through blood vessels. Doppler ultrasound is a special type of ultrasound that evaluates blood
flow through a blood vessel, including arteries and veins in the abdomen, arms, legs, and neck.
In medicine, ultrasound is used to detect changes in appearances of organs, tissues, and vessels
or detect abnormal masses, such as tumors. It’s all based off the same principles involved in
sonar used by bats, ships, and fishermen. When a sound wave strikes an object, it bounces
back, or echoes. By these waves is when we are able to determine how close an object is, it’s
size, shape, and whether the object is solid, filled with fluid, or both. A very common type of
ultrasound is a pregnancy ultrasound where sound waves are used to check on how the fetus is
developing in the womb. Sonogram can determine a birth date, heart rate, or to see if there are
multiple fetuses. They can also find if an embryo is implanted in a fallopian tube, miscarriage
potential, or other problems in the placenta, uterus, and cervix. Getting into pregnancy
trimesters, they can monitor the baby’s growth, heath, position, and if there is any birth
defects, Down syndrome, and the amount of amniotic fluid, and early recognition of these
things can help solve problems and resort to a healthy mother and baby.
Mammography is
used in a low-dose x-ray system to aid in the early detection and diagnosis of breast diseases in
women. It all began in 1913, when a surgeon by the name of A. Salomon did a study on 3,000
mastectomies; the basis of mammography. Mammography is also a diagnostic that helps treat
medical conditions but in the breasts. A type of mammography is a full-filled digital
mammography, and this is almost similar to a digital camera in the way it works. It has solid
state detectors that convert into electrical signals. After these pictures have been shot they are
then printed off onto a screen so the patient can then view just as much as the doctor.
Computer aided mammography is more into the computer animated. It looks for abnormal
clarifications such as, mass, density, and can clarify or notice cancer. Some signs of cancer may
be a lump in the breast, paint, or nipple discharge. Mammography is essential in detection
because it can detect something wrong in the breast up to two years before anything can be
felt. Some guidelines from the U.S. Department of Health and Human Services (HHS), the
American
Cancer Society (ACS), the American Medical Association (AMA) and the American
College of Radiology (ACR) recommend”screening mammography every year for women,
beginning at age 40. Research has shown that annual mammograms lead to early detection of
breast cancers, when they are most curable and breast-conservation therapies are available.” It
is more important to women who have a history of breast cancer in genetics have advised to
get expert medical advice about whether or not to start screening before the age of 40 to make
sure they catch any problems that may start to form. There are limitations in Mammograms,
like breast implants. They do block certain things but a good experienced Radiologist or
technician knows how to get around it without hurting anything and can with furthermore
detect any resorting issues.
Nuclear medicine uses radioactive substances to get
images of the body and then treating diseases. When a patient is undergoing radiation for
cancer a PET scan is used to diagnose patients, and this is then where nuclear medicine starts. A
lot of techniques are used today by doctors so looking inside the body isn't painful. Some of
these techniques include X-rays, MRI, CAT scan, and ultrasound. All of these have different
advantages and are used in for different areas and parts of the body for different conditions.
Nuclear Medicine imaging gives doctors different ways of looking inside the body with uses
radioactive substances. These techniques include: Pet scan "positron emission tomography,
SPECT single photon emission computer tomography, cardiovascular imaging, and bone
scanning. Nuclear Medicine is used for finding tumors, weak spots in blood vessel wallks,
irregular blood flow, blood cell disorders, and inadequate functioning of organs. all tests are
different and depend on the patients disorder and how they are being diagnosed.
magnetic resonance imaging (MRI) has been used tremendously just in the last few
decades. Dr Raymond Damadian a physician and scientist wanted to figure out how to use a
machine that could scan the body with the use of magnets. Not only him but college students
were trying to figure out the solution also. Nothing happened until July 3, 1977 when a
graduate student volunteered to be the first human being to test out the MRI exam. It took
almost five hours to complete and produce just one image. The origional machine which goes
by the name of "indomitable," is now owned by Smithsonian institution.
Doctors use MRIs to scan and help diagnose multiple sclerosis, brian tumors, torn ligaments,
cancer, and torn ligaments just to name a few. MRI is one of the safest ways to see inside the
body without cutting it open. During an MRI the patient is asked to take off any jewelry, strip
credit cards and asked detailed questions about if the patient may or may not have metallic
instruments inside of them. Also, some things they ask are to make sure you don’t have any:

implanted drug infusion ports

implanted electronic device, including a cardiac pacemaker.

artificial limbs or metallic joint prostheses

implanted nerve stimulators

metal pins, screws, plates, stents or surgical staples
The next step is to put you on a slap and push you into a hole that is barely large enough
for a person. The patient then hears loud noises, and laying perfectly still the technician will
repeat the process.
In this machine two types of magnets are used. The first one is the Resistive magnet
which are superconducting magnets, but lack liquid helium, when the magnets require a huge
amount of electricity. The second magnet is Permanent magnets. These magnets have a
constant magnetic field, although, they are so heavy it's hard to keep composure with a large
magnetic field. And thirdly, there are also three gradient magnets in the MRI, these are a low
strength compared to the others and these create a variable field, which allows all the different
parts of the body to be scanned
.