So now let's discuss medical imaging.
Medical imaging involves techniques that allow physicians and other health professionals
to both view images of the human body as well as use those images
to diagnose anatomical and physiological abnormalities. Let's think about this.
Do you think you can name all the medical imagining procedures?
So the first one is an X-ray, the second one is an MRI, and the third one is a CT scan.
Let's look at these in a little bit more detail.
So first off, let's start off of radiography.
In radiography, you're probably familiar with this.
This is where we're going to look at X-rays.
So an X-ray is going to basically be a series of X-rays that are gonna pass through the body
and they're gonna produce an image of the interior structures inside of the body.
And so what you get from this is a two-dimensional image
that is displayed on a radiograph, also referred to as an X-ray.
This procedure is relatively inexpensive, it's very quick, and is a simple procedure to perform.
It usually provides sufficient information for diagnosis
and what you will see when you look at an X-ray are the dense structures in the body,
the hollow structures in the body which will appear black,
and then the shades of gray are the intermediate density structures
such as the skin and the muscles in the body.
Another form of radiography that you may be familiar with is mammography.
In this, what we're actually gonna do is use low doses of X-ray in order to visualize soft tissue in the body.
We can also inject a medium. Also known as contrast medium
which will allow us to visualize hollow structures by creating a contrast
between the hollow structures and their surroundings.
And so examples of radiography that use this contrast medium would be things
such as angiography where we're gonna use it to visualize the blood vessels
and also things like intravenous urography, as well as barium contrast X-rays.
So another type of imaging that is used is called an MRI or magnetic resonance image.
And in this, we're gonna expose the body to a high energy magnetic field.
What this does is it causes the protons or the atoms, the positively charged atoms inside of your cells,
to arrange themselves in a certain type of way.
And then we use radio waves to read that pattern and produce an image.
And so the result of this is a two or three-dimensional blueprint of the cellular chemistry.
Like the X-ray, the MRI is also a relatively safe procedure to undergo
however if a patient has any metal in their body, you probably don't wanna do this as,
you know, magnets and metal are not a good combination.
This allows us to show the soft tissues in the body but we are not able to visualize bones.
The reason why is because the location of the cells in the bone
makes it very difficult to be visualized using this type of procedure.
We'll talk about that when we get to the skeletal system.
So this process is most useful for differentiating between normal and abnormal tissue
so you're looking for tissue that doesn't quite belong
or doesn't quite look like what it's supposed to look like.
And it's especially good for detecting tumors and also clogged arteries and things of that nature.
And because this looks at cells, we are able to also measure blood flow
by looking at the red blood cells inside of our vessels.
The third type of medical image that we're gonna talk about is the CT scan or the computed tomography scan.
In this scan, an X-ray beam is gonna trace an arc at multiple angles around a section of the body
and what you're gonna get is a transverse section of the body that you can see on a monitor.
So recall transverse section, we're gonna divide top to bottom.
This allows us to visualize soft tissues and organs, and it actually provides a lot more detail
and contrast than our traditional radiographs such as X-rays.
We can also look at the different tissue densities by looking at the different shades of gray
that are presented in the image. If we put multiple scans together,
you are also able to build a three-dimensional view of the structure that you're visualizing
and you can also do whole body CT scanning and with that,
we're usually able to visualize the entire torso or trunk area of the body.
So another type of medical imaging procedure that you may be familiar with is the ultrasound.
This is often used during pregnancy and what this is, is sound waves that are used to create an imagine.
So the sound waves bounce off of the different structures in the body
and it creates an image on a video monitor or what we refer to as a sonogram.
This procedure is also safe, it's pretty noninvasive, it does not involve any pain or use of any dyes of any nature,
and again, it's used most often during pregnancy but it's also used for other things
such as measuring blood flow, looking for deep vein thrombosis or blood clots in the blood,
and other things of that nature.
The next scan that we'll talk about is the PET scan. In a PET scan,
what we're going to do is we're gonna use a substance that emits positrons
or these positively charged particles and they're gonna be taken up by the tissues.
These positrons are then going to interact with the body tissues and they're going to produce gamma rays,
and it's the gamma rays that are detected by the cameras in the PET scan.
And then from there, computer image will actually show the different signals
and they'll display them in different types of color.
In this, we're going to show where the injected substance is actually being used inside of the body.
So this is a little bit of a different type of scan because not only are we able to visualize the structure
but in this way, we are actually visualizing some of the physiology of the body structures
that we're studying such as the brain and the heart.
And lastly, we have endoscopy. In endoscopy, what we're basically using is a lighted camera.
See, we insert this lighted instrument that has a lens on it into a part of the body,
usually a body organ or a body cavity. And then we are able to view that
and then project that image onto a monitor.
Examples of different types of endoscopy include the colonoscopy
which is examination of the interior portion of the colon or a laparoscopy
where we're going to examine the other organs of the abdominopelvic cavity.
And finally, if you ever go to the orthopedic surgeon, you may undergo an arthroscopy
where they are going to examine the interior of your joints.
And this concludes our introduction to the human body. Thank you for watching.