Medical Machinery
What is the difference between a
CT scan, MRI, PET, X-Ray and
Ultrasound?
CT SCAN or CAT SCAN
Computed Tomography
by using an x-ray beam passing through
the body to produce an image. The CT
scan x-ray beam spins on a ring in a
round part of the scanner called the
gantry. You lay on a table that moves in
and out of the gantry while the table
passes you through the spinning x-ray
beam. CT USES A MAGNETIC IMAGERY
similar to an x-ray.
MODERATE to HIGH RADIATION
EXPOSURE
MRI
Magnetic Resonance Imaging
• A powerful MAGNETIC field used to align
nuclear magnets with water (hydrogen atoms)
in the body.
• Uses magnets and radio waves to create the
image
• Best used for soft tissues of the
body
• There are many types of MRIs
• NO RADIATION EXPOSURE
CAT versus MRI
• MRI shows tendons and ligaments very well
• Tendons and ligaments around the shoulder
and knee are best seen in an MRI.
• This is due to the density of the tissues that
compose the tendons and ligaments.
• Spinal cord is best seen by MRI for the same
reason. The density of the spinal cord and the
composition shows better on an MRI.
CAT versus MRI
• CT scan is the preferred modality for cancer, pneumonia, and
abnormal chest x-rays.
• Bleeding in the brain, especially from injury, is better seen on
CT than MRI.
• But a tumor in the brain is better seen on MRI.
• If you've been in an accident, organs can get torn or damaged.
• CT shows organ tear and organ injury quickly and efficiently.
• Broken bones and vertebral bodies of the spine are better
seen on CT but injury to the spinal cord itself is displayed on
MRI far better than CT.
• CT is far superior at visualizing the lungs and organs in the
chest cavity between the lungs.
• MRI is not a good tool for visualizing the chest or lungs at all.
CT Scan Machine
MRI Machine
• First photo is a MRI of brain tumor you can see two
tumors
• Second photo is a CT of same brain showing only one
tumor. (better in showing bleeding on the brain in
trauma patients like bus/ car accidents)
CT images of cervical spine (neck area)
• CT for bone fractures (shown) shows the
BONE of the cervical spine
• MRI for spinal cord injury (area between bones)
Pelvis CT
Can you find the pelvis fracture?
Pelvis CT
Can you find the pelvis fracture?
Abdomen CT
• With CONTRAST…you would have to drink a
chalky liquid in order to visualize particular
areas OR get an IV for dye
• Black spots show lesions,
Cysts or tumors
CONTRAST CONTENTS
• Oral contrast is composed of a mineral called
barium sulfate (BaSO4).
• Barium is a metallic element that is chemically
similar to calcium but more reactive.
• The compound works due to barium's
relatively high atomic number (Z = 56), since
large nuclei absorb X-rays much better than
smaller nuclei.
Intravenous Contrast
IV Content
• Contains IODINE
• Some people with shellfish allergies have an
allergic reaction to this contrast
• When administered, it brightens internal
organs, arteries, veins and tissues as it courses
through them.
PET SCAN
Positron Emission Tomography
• an imaging test that can help reveal how your
tissues and organs are functioning.
• To show this chemical activity, a small amount
of radioactive material must enter your body.
• The radioactive material may be injected into
a vein, inhaled or swallowed
• Isotopes needed (C-11, N-13, Rb-82)
PET SCAN
More radioactive material accumulates in
areas that have higher levels of chemical
activity. This often corresponds to areas of
disease and shows up as brighter spots on the
PET scan.
A PET scan is useful in evaluating a variety of
conditions — including neurological problems,
heart disease and cancer.
PET with CAT
The PET/CT is the most advanced medical
imaging technique available today. It
combines Positron Emmission Tomography
(PET) with Computed Tomography (CT).
A PET scan offers the ability to detect changes
in cell function
ULTRASOUND
Ultrasound is cyclic sound pressure with a
frequency greater than the upper limit of
human hearing
SONOGRAM
The most well known application of
ultrasound is its use in sonography to produce
pictures of fetuses in the human womb
Sonogram
It’s a Boy!
Sonogram
It’s a Girl!
No boy parts…
3-D views
TWINS!
TRIPLETS
X-Ray
X-Radiation
• X-radiation (composed of X-rays) is a form of
electromagnetic radiation
• They are shorter in wavelength than UV rays.
• X-rays can penetrate solid objects, and their
largest use is to take images of the inside of
objects in diagnostic radiography and
crystallography
• X-rays are a form of ionizing radiation and
exposure to them can be a health hazard.
Electromagnetic Spectrum
PLEASE NOTE
• Sound waves (ultrasound) are not a part of the
Electromagnetic Spectrum
• X-Rays are a part of the Electromagnetic
Spectrum
• They travel at different speeds. Sound waves
are slower.
• SPEED OF LIGHT= 3.00 x 108 m/s
(300,000,000 m/s)
• SPEED OF SOUND= 340 m/s
• Sound waves travel faster in water than in air.
Cost of an MRI
• MRI cost can range between $1000 to $3,500
depending upon which MRI procedure is
performed
• Average cost is over $1000
• (example: brain MRI vs. shoulder MRI) and
where you have the MRI test performed
Cost of a CT scan
• Cost $300-700 per body part
• Cost of a diagnostic scan (this is one that your
doctor orders because of an injury or
symptom) $600- 1500
• Full body CT scan with contrast- up to $6000
• Contrast is a dye injected or swallowed to
show tissues…etc…
Cost of Ultrasound
• Cost of ultrasound is typically around $200
• Also depends on which area is being viewed.
Cost of a X-Ray
•Depends on the part and how many images
are taken
•$80-250 or higher
•Example: a pelvic x-ray can cost $1,200
RADIOLOGY
• Radiology is the branch or specialty of medicine that deals
with the study and application of imaging technology like xray and radiation to diagnosing and treating disease.
• A Radiologist is a Medical Doctor (M.D.) that reads MRIs and
CT scans.
• Radiologists know their chemistry!
• Schooling
– 4 years (Undergraduate degree…like Chemistry, Biology, Genetics, etc)
– 4 years (Medical school)
– 2-4 years (Residency-get paid here)
Median salary is $290,000 per year
According to salary.com
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Radiation Physics
Anatomy and Physiology
Principles of Radiographic Exposure
Radiobiology
Radiographic Examination
Radiographic Studies
Fluoroscopic Studies
Orthopedic Studies
Special Imaging Studies
Patient Care
Patient Physical Assessment