Distinction assignment from BTEC Applied Science Unit 21- medical physics application. 21AB includes the principles, production, benefits, and uses of both ionising and non ionising radiation in medical applications. explains how they are used for diagnosis and treatment of diseases and why they ar...
P1 non-ionising
Ultrasound:
An ultrasound is a medical imaging
technique which uses sound waves to
produce an image of the inside of the body
and is commonly used to help monitor the
development of a fetus while still in the
stomach developing. Ultrasounds are used
to image a person's internal body
structure, like a person's pelvic and
abdominal organs, their heart and blood
vessels, tendons and muscles. Medical
Ultrasound machine work based on the
principle of sound waves where a device
known as transducer emits high-frequency sound waves into the body. These sound waves will
bounce off different organs and tissues in the body resulting in the creation of echos inside the
body (sound waves). Once echos are made inside the body a machine known as a transducer
will pick up the echos and convert the sound waves into an image which will be displayed on
the screen of the ultrasound machine. An Ultrasound is used to examine organs for any
abnormalities and any diseases like, for example, the liver, heart and kidney. Ultrasound
machines are also used for biopsies and injection because it uses the image to help guide a
small needle for laboratory testing and analysis. Ultrasounds require specialized equipment like
for example, a transducer which emits 2 megahertz (Mhz) and receives sound waves and a
computer system which turns the sound waves (echo) into an image which helps to analyze in
the aid of diagnostic and treatment of patients.
The main equipment in an ultrasound is:
Earthed Case: The earthed case is used for safety because it helps prevent any of the
equipment being damaged by a electrical hazard by preventing any excess electrical charge
,which will help keep the machine in good working condition and the patient or person
controlling the machine from any chance of being in danger.
Coaxial Cable: The coaxial cable helps transmit the electrical signal from and to the transducer.
The coaxial cable is very important because it helps keep the signal conveyed because it plays a
important role in the production of how the quality of the ultra-sound image will be.
Absorber: The absorber helps with the production of a accurate and clear ultrasound image by
reducing the amount of reflection and echo (sound waves) which could affect the outcome of
the image.
Piezoelectric Crystal and Plastic case: The crystal is a important part of the transducer because
it plays a role in converting the electrical signal into sound waves and back. Whereas the plastic
case is a protective layer which helps keep all the delicate components safe from any damage
and in working conditions to be able to produce a high-quality ultrasound image.
Monitor screen: The monitor screen plays one of the lead roles in the production of ultrasound
image because on the screen the image will be displayed which will help allow any medical
professional to see the internal structure of the body and keep up with the growth of babies.
An ultrasound transmission consists of sound waves which are emitted in short pulses.
The probe in the transducer emits and receives the ultrasound waves, a small device which acts
as a microphone and a speaker. How can this b
The piezoelectric crystal vibrates as a response to the alternating voltage, when it is placed
against an individual's skin and driven at high frequency which are produced the ultrasound
pulses will travel through the body. As the pulses travel outwards and encounter different
layers within the body the ultrasound waves will start to reflect towards the main source. Then
the returning signal will cause the crystal to drive in reverse resulting in the production of an
electrical signal which will result in the production of an image.
When the ultrasound waves encounter a change in density like when they pass from 1 tissue to
another , the waves can be reflected or refracted. Areas which have a high density like organs
and bones can lead to more absorption or reflection of the ultrasound waves which will result
in different levels of brightness on the image. So the denser the darker the image.
Ultrasound= Ultrasound can be used to help treat kidney stones, benign tumors and malignant
tumors because medical ultrasounds is a non-invasive procedure which targets a specific area
with high-frequency sound waves which can break kidney stones into smaller pieces making
them easy to pass. Ultrasounds are usually used to help diagnose a range of conditions like
tumors, narrowing blood vessels, stroke , kidney stones and heart attacks. For kidney stones
ultrasounds are used to diagnose ultrasound by doing a pelvic ultrasound which will produce
a image of the kidneys and blader which can be used to help identify what is blocking the
flow of urine and help find and identify the stones. There are different types of ultrasound,
,external ultrasound which is used for screening of fetus , internal ultrasound which is used for
producing images of the organs in more detail and endoscopic ultrasound which is used for
examining the gullet, stomach and the lymph nodes in the chest and this can be done by
inserting a thin long flexible tube which is known as a endoscope and is inserted into the
body through the mouth.
MRI:
An MRI machine which is known as Magnetic
Resonance Imaging uses high radiofrequency waves
and also strong magnets which are used to produce
detailed images of the different soft tissues in the
body. MRI machines use strong radio waves and a
magnetic field to develop a high-quality detailed
image of the individual's internal structure. This due
to the way which hydrogen atoms behave in the
body when exposed to a strong magnetic field and
radio waves because the signals produced by the
atoms will then be processed to be able to produce
and generate a internal image of the individual to be able to diagnose the individual and check
for any abnormalities and health checks. MRI images are analyzed by radiologists because they
are trained to be able to analyze any anomalies and abnormalities in MRI images which they
may know what it may be.
The production of MRI machines requires a lot of money because they require specialized
equipment and technology which can't be found anywhere. The machine has a strong magnet,
a computer system and radiofrequency coils. The magnet helps create a very strong magnetic
field while the radiofrequency coils emit the radio waves and receive the signals coming from
the body. While the computer systems process the data to create the image used in the
medical field to diagnose and treat patients. An MRI machine is commonly used to examine a
person's spine, brain, soft tissue and joints because the MRI machine can produce a detailed
image of the inside of an individual's body which can be used to test and diagnose for any
injuries, abnormalities and tumors without the need of any surgeries happening because it is a
non-invasive treatment which is painless.
,The main magnet is large , permanent and superconducting electromagnet. It is a coil which
carries a steady electric current which generates a magnetic field that runes through the center.
The main magnet is a long lasting magnet which can be cooled down by blowing off liquid
helium , helium cools down the superconducting magnets to a temperature of 4.15 Kelvin
which is approximately –269 C.
The MRI scanner coils specialized devices which transmits and receives radio waves that are
used to generate an image. The MRI scanner coils are placed around the required body part
which is being scanned to help optimize the signal to help generate a high quality image.
The bore of an MRI machine which is the sliding platform tunnel like where a patient will lay
down during the MRI scanning, the bore is very important because it allows the individual
laying down to stay put without moving for the MRI image to be able to produce a accurate
internal image of individual which is why it is important that the size and design of the bore to
be comfortable for all patients of all size and lengths (different body types).
Radiofrequency coils produce an input radio wave which excites the nuclei and results with a
nuclear magnetic resonance which is also know as NMR. The radiofrequency coils need to
maintain a power output of 1kW.
Output signal receives is important tunning coils which pick up the output radio waves from
the protons in the resonance. There are many types of output signal receivers , the type used
will vary depending on the type of image which is being produced like for example if the image
needed is of a more focused tissue or of a large volume area.
An MRI machine is linked to a powerful computer because the computer controls the scanner
collects the data from the scanner coils so that it can process the data to produce a detailed
image of the body.
The Gradient coils are used to be able to create range of magnetic fields which are necessary
for the spatial encoding (process to find where a signal is coming from the body to be able to
create a detailed MRI image) in the MRI image which is crucial for accurate diagnostic and
treatment of a patient.
Scanners use very strong magnet fields and radio waves to be able to produce a detailed
internal image of an individual which is why the equipment used to make the scanner are
specially designed and assembled a certain way to make sure that all images are accurate and
reliable.
magnetic resonance imaging is used to help diagnose and help with joint and tumors injuries.
MRI can be used to diagnose tumors because it helps provide a detailed image which is used by
a professional to help determine the location, characteristics and size of the tumor which is
very important while planning for treatment like radiation therapy, chemotherapy or surgery.
, MRI can also be used to help diagnose joint injuries because MRI can help show the soft tissue
which is damaged like the tendon or ligament tears which may not be visible on an X-ray.
Laser:
A medical laser is a tool used by
professionals. It emits a concentrated
beam of light used in different medical
procedures targeting specific cells and
tissue. Medical lasers are commonly used
by dermatologists for treatments like
tattoo removals, skin treatments
(rejuvenation) and hair removal because the laser will be absorbed by the wanted area which
will allow for a precise and more thorough treatment. Another way in which medical lasers are
used for laser eye surgery (LASIK) by ophthalmologists (doctors which treat eye conditions). The
light of the specific wavelength passes through a gain medium which helps to amplify the
light with higher energy though the use of stimulated emission. The amplified high energy
light is then either emitted as a narrow beam or is spread out , but that will depend on the
what the use and area which the laser is being used and will depend though the laser
oscillator.
All the parts in a medical laser work together to be able to make a high-intensity laser beam
which can be used for medical procedures and the main parts are:
Gain Medium: The gain medium is a material used to enhance the light , it comes in different
forms gas , liquid or solid because it can be excited to a very high energy state. When the gain
medium is stimulated by external sources of energy like a laser and electricity it then emits a
light.
Reflector: The reflector is the main component which reflects the light back into the gain
medium making a feedback loop which is the part of the system which is some or all the part of
the system’s output is then later used as input later . The reflector help keep the amplification
of the light inside the gain medium which helps make a more precise and accurate light.
Laser Oscillator: The laser oscillator is what makes the main laser beam which consists of the
reflector and gain medium working together to make it , they stimulate the production of more
light and resuling in a more coherent bream.
Amplifier: Amplifier are not always used in medical lasers. The amplifier uses the main laser
beam which was generated by the oscillator and increases the power by processing it though
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller usaydali. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.33. You're not tied to anything after your purchase.
