| Question |
Answer |
| ***Who is credited with inventing CT? in what year? |
Godfrey Hounsfield in 1972 |
| T/F Xrays are an excellent way to view facial and skul fractures? |
No xrays SUCK for skull fractures - use a CT |
| List the Hounsfield units that's attenuated for each tissue in a CT? |
Cortical Bone = +1000HU, Blood = +40HU, CSF = +15HU, Water = 0HU, Fat = -100HU, Air = -1000HU |
| What is a series of settings which affect the number of shades of gray displayed in a CT? |
A window |
| What type of window allows you to see: 1. differentiation of cortical and medullary space? 2.allows visualization of muscle, organs, discs? |
1.bone window 2.soft tissue window |
| 1. What is the average CT number called? 2. What is the range of CT numbers above and below the window level called? |
1.window level 2.window width |
| 1.What is the window level of a bone window? 2.What is the window level of a soft tissue window? |
1.bone window = +200HU 2.Soft tissue window = +20 to +40HU |
| What type of procedure is invasive, by injecting an agent within the subarachnoid space to indirectly visualize the subarachnoid space, spinal cord, and nerve root sheaths? |
Myelography, not done much today unless patient is obese or claustrophobic and a MRI is impossible |
| What type of technique obtains "live xray images"? |
Fluoroscopy |
| What type of technique uses high frequency sound waves to create an image of living tissue, tendons, and ligaments? |
Ultrasound - remember it is non-ionizing but changes temperatures in tissue by 1 to 2 degrees. |
Buen Viaje lv.2 ch 8
