MEDICAL IMAGING TECHNOLOGIES (slide 13) Flashcards
X-ray
How does it work?
-radiation that can penetrate skin and soft tissues but cannot
penetrate metals and bones (ie. dense tissue)
-dense structures that absorb radiation appear white on the
radiograph
X-ray
Advantages
quick, painless, non-invasive
X-ray
Disadvantages
can cause changes and mutations to DNA (need to wear lead
vests)
X-ray
Examples of use
Diagnose bone injuries (most common)
Check for cancer, diagnose problems in organ systems (ie.
cardiovascular and respiratory diseases), mammograms,
observe size of heart or check structure of blood vessels,
cavities in teeth
A beam of x-rays can be used to kill cancer cells
Ultrasound
How does it work?
-high-frequency sound waves to produce images of body tissues
and organs. Sound waves enter the body and are reflected back by
internal body structures
Ultrasound
Advantages
No documented risks, can see organs and movement in real
time, painless, no radiation
Ultrasound
Disadvantages
can’t be used for intestinal area (gases/air can blur the images
produced), not for bone (cannot penetrate bone), special
preparations sometimes needed (ie. fasting)
Ultrasound
Examples of use
Study soft tissue and major organs
Study developing fetus (most common)
Guides the needle during a biopsy
Diagnose heart problems
CT or CAT Scan
How does it work?
-using X-ray equipment to form a three dimensional (3D) image
from a series of images (2D) taken at different angles of the body
Advantages (ie. benefits) CT or CAT Scan
more detailed than simple x-ray, can do bone, soft tissue and
blood vessels at the same time
frequently used in ERs because is painless, quick, and provides
detailed information
Disadvantages (ie. risks) CT or CAT Scan
radiation can cause changes and mutations to DNA (need to
wear lead vests)
Examples of use CT or CAT Scan
Diagnose cancer, abnormalities to skeletal system, vascular
diseases
Image bone, soft tissue and blood vessels all at same time
CT of head can detect bleeding of brain
How does it work? MRI Scan
(Magnetic Resonance Imaging)
-uses powerful magnets and radio waves to produce detailed images
of the body
-magnets produce magnetic field that interacts with hydrogen
atoms in the body to produce an image
Advantages (ie. benefits) MRI Scan
(Magnetic Resonance Imaging)
less confines when testing is being done, open MRI is an option,
painless, greater detail than CT
Disadvantages (ie. risks) MRI Scan
(Magnetic Resonance Imaging)
claustrophobia, can’t move while pictures are being taken, takes
more time than CT
PET Scan (Positron Emission Tomography)
How does it work?
-type of nuclear medicine; patient is given a radioisotope that
emits particles/positrons (radio isotope emits radiation that can be
detected by a camera/computer and converted into an image)
PET Scan (Positron Emission Tomography)
Advantages (ie. benefits)
can pinpoint a problem area when CT scan is not able to,
painless, non-invasive, radioisotopes are simply excreted
PET Scan (Positron Emission Tomography) Disadvantages (ie. risks)
exposure to gamma rays, claustrophobia, radioactive material
can cause allergic reaction
PET Scan (Positron Emission Tomography) Examples of use
Used most often to detect cancer and see how treatment is
working
Detects heart disease and brain disorders (e.g. Alzheimer’s
disease and epilepsy)
Can be used in combination with CT scan to produce cross-
sectional images
Fluoroscopy How does it work
-type of x-ray
-uses a continuous beam of X-rays to produce images. The patient
ingests barium or iodine to see organs more clearly
Fluoroscopy Advantages
can see movement in real time, painless
Fluoroscopy Disadvantages
have to ingest a dye, can cause changes and mutations to DNA
(need to wear lead vests)
Fluoroscopy examples of use
Shows the movement of organs, such as the stomach,
intestine, and colon
View blood vessels of heart and brain for narrowing or
blockages (angiogram)
Biophotonics (Endoscopy)
how does it work
-an examination of tissue removed from a living body to discover
the presence, cause, or extent of a disease; use of microscope
allow for lab technicians to examine the shape and size of cells, as
well as other abnormalities
Biophotonics (Endoscopy)
Advantages
can be used to distinguish benign tumours from malignant
tumours
Biophotonics (Endoscopy) disadvantages
invasive, not all tissues are easily accessible
Biophotonics (Endoscopy)
examples of use
Used most often to examine moles and tumours to detect
cancer
Among others, biopsies can be used for bone marrow, skin, and
breast tissue
Can be used with endoscope to take a biopsy of the GI tract
or lungs
A hockey injury may be a fractured hip.
I would do an X-ray because it’s probably a bone injury.
Assessing a neck injury after skiing.
I would do a CT Scan to check for soft tissue injury.
A possible brain injury following a car accident.
I would do a MRI Scan to check for brain damage.
An abdominal pain could be a gallstone.
Ultrasound because it is good at diagnosing or excluding gallstone
