Radiology Flashcards
How do you differentiate a fracture from a growth plate on x-ray?
Fracture = jagged line
Growth plate = straight line
What 3 factors determine absorption of an x-ray beam?
Thickness of tissue. Density of tissue. Atomic number of a tissue to the 4th power.
What does doppler ultrasound allow you to image?
Blood flow
Is the wavelength of x-rays shorter or longer than visible light?
Shorter
What percentage of inpatients have some sort of imaging at RMH?
95%
What is the unit of measurement of the absorption of a voxel?
Hounsfield unit
What do ultrasound waves reflect off?
Tissue interfaces
Which has better spatial resolution: CT or x-ray?
X-ray
What are the 4 essential things to have the Pt do when taking a CXR?
Full inspiration, erect, PA, scapula out of the way
When windowing a CT, what determines the contrast of the image?
Window width
What are 3 advantages of x-radiography over CT?
Cheaper, less ionising radiation and better spatial resolution
What is the most common radioisotope used in gamma ray imaging?
Technetium
What is the advantage of gamma ray imaging?
Functional imaging
How much stronger is a 1.5T MRI machine than the Earth’s magnetic field?
30,000 times greater
How is iodine intravascular contrast medium excreted?
Kidneys