Imaging Techniques Flashcards
What is X-Ray and what is it used for?
Uses X rays (very short wavelength electromagnetic waves)
Dense structures appear light. Hollow appear dark
Used for detecting broken bones; finding breast tumors; measuring density of bones.
Cons: radiation exposure
What is Computed Tomography (CT) scans? What is it used for?
Computerized reconstruction of a series of X-ray images
Provides detailed cross-sectional pictures
Used for images of bones, soft tissues, and blood vessels
Cons: more radiation exposure than X-rays
What is Digital subtraction angiography? What is it used for?
Angiography is visualizing blood vessels by X ray or CT scan
Injection of X-ray absorbing contrast agent
Digitally subtract images from before and after - - very clear images of blood vessels
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Used for: detecting blood vessel abnormalities
Cons: Time-consuming and expensive. Can have reaction to agent.
What is Positron Emission Tomography? (PET) What is it used for?
Gamma rays that are emitted by radioactively tagged tracer molecules injected into the body.
Specific molecules are attracted to the target, thus showing where it is.
Used for: Detecting cancer or monitoring the response to treatment. Can sometimes diagnose Alzheimer’s disease.
Cons: radiation exposure; poo image resolution.
What is Magnetic Resonance Imaging (MRI)? What is it used for?
Powerful magnets and radio waves to image location of hydrogen atoms (mostly in water)
Distinguishes between tissues with high/low water content.
Used for: Imaging of brain, spinal cord, and nerves to detect abnormalities; assessing joint, ligament, cartilage, and other soft tissues; fMRI allows visualization of the activity in specific brain regions
Cons: more expensive and much slower than CT
Cannot be used with metal implants
What is Ultrasound Imaging? What is it used for?
Uses high-frequency sound waves that reflect off body tissues
Real-time
Inexpensive and easy to use
Used for: Monitoring a fetus; diagnosing abdominal or pelvic disorders; can detect atherosclerosis and heart valve disorders.
Not used for: air filled structures and surrounded by bones
Cons: Images tend to be lower resolution.
