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What is advanced imaging?
anything that is not plain film radiograph (x-ray) TERM 2
Purpose of a CT scan
DEFINITION 2 noninvasive test that that provides sectional imaging of bone and most soft tissues. TERM 3
What is CT especially good at highlighting?
DEFINITION 3 especially good for the chest (lungs) and abdomen (organs) with better anatomical resolution than a radiograph. (more airspace)Able to measure bone density (predict fractures) and identify tumors.vessels, brain, tendons TERM 4
What is a
CT?
DEFINITION 4 computed (Axial) tomographya computerized analysis of the changes in absorption (object radiodensity) that produces a detailed cross sectional 3-D reconstructed image TERM 5
What is a CT commonly used
for?
DEFINITION 5 commonly used to diagnose spinal lesions and diagnostic studies of the brain
Where does the "axial" portion of a CT come
from?
The axial portion comes from the images being taken in the axial (transverse) anatomical plane TERM 7
Principles of CT
DEFINITION 7 Same as plain film radiographsX-rays are absorbed (attenuated) by body tissuesBody tissues are in shades of grayCT images are in cross sections (axial, transverse) and can be rearranged in varying planes and angles by the computer TERM 8
CT Scanner
Elements
DEFINITION 8 gantryoperators consolecomputers TERM 9
Gantry
DEFINITION 9 contains x-ray tubehigh voltage generatorcollimatordetector arraydata acquisition system TERM 10
Operator's console
DEFINITION 10 desk where operator controls scanning process and selects slice thickness, reconstruction algorithms
What is windowing?
is the range of densities and each image is a window.Humans can see about 30 shades of gray, but computers can see hundredsA window lets us see what we usually cannot see TERM 17
What kinds of windows are there?
DEFINITION 17 There are soft tissue windows (for gray and white matter) and bone windows (for cortical and cancellous bone) TERM 18
Describe the difference in slice thickness and
pixel size?
DEFINITION 18 Thinner slices and smaller pixels improve spatial resolution.Thicker slices and larger pixels improve contrast TERM 19
CT is the choice for neuroimaging in what
settings?
DEFINITION 19 Acute settingsTrauma TERM 20
Imaging of the brain for CT & MRI follow
patterns used in musculoskeletal imaging and
are based on what?
DEFINITION 20 Cell densityFatFluid content
Variants of CT
3-D CTCT myelography are variants of CT TERM 22
Amount of ionizing radiation in a CT
DEFINITION 22 CT exposes the patient to more ionizing radiation than a radiograph TERM 23
What is Tomography?
DEFINITION 23 Tomography refers to imaging by sections or sectioning, through the use of any kind of penetrating wave. TERM 24
Tomograph
DEFINITION 24 A device used in tomography is called a tomograph, while the image produced is a tomogram. TERM 25
Viewing the CT
DEFINITION 25 When viewing STANDARD CT or MRI keep this in mind:You view the image as if the patient were in a supine position and you were looking from inferior to superior.Sagittal images are viewed from left to right.
Why do people weaken with age?
Loss of number and size of fast twitch fibers. Decreased cross sectional area. Decreased range of motion as in ligament and tendon shortening. Decreased joint function as in arthritis. Excessive weight gain.
