Introduction Flashcards
How do organs rotate in regards to the II?
Objects closer to the x-ray tube will move in the opposite direction of motion- with respect to objects that are further away from the x-ray tube
Explain distortion?
magnification.
further objects are magnified.
e.g. part of the transverse colon is more magnified then the ascending colon because the transverse colon is more anterior so further away from the II.
How is an image diangostic?
You need to describe where it is and how it relates to surrounding objects.
What is a baseline image?
Looking at previous imaging to see what is normal for the patient and what is not. You can change this baseline image.
If there are no previous images, then a control image before you start the procedure acts as your baseline.
what is the function of the common bile duct?
carries bile from the liver and the gallbladder through the pancreas and into the duodenum (the upper part of the small intestine)
where does the common bile duct lie in regards to the duodenum?
It lies posteriorly
what kVp is used for barium studies and iodine studies
barium- 90kVp
iodine- 70kVp
what is the definition of a profile shot?
A shot such that it shows the maximum amount of anatomy in an image.
What is the definition for a tangential view?
A tangentia view is used to see how the pathology has affected the entry point of the wall of the organ that it is in.
What is the radiographers responsibility when using a tangential view?
a) To produce quality image
b) to be able to locate/localise the object.
c) Describe using images extent of the pathology
d) to be able to visualise with minimal interference from local near by objects.
Describe the 4 different stages of cancer
1) it is localised
2) its spread within the organ
3) gone outside of the organ broke through the wall and into the lymphatic system.
4) its gone everywhere
What are basic protocol views?
derived when there is no pathology (e.g. just a normal series)
What are additional protocol views?
Derived to image a pathology (taking into account the basic views). This additional view needs to add a greater diagnosis for the patient
what is the purpose of a tangential view?
helps you see the entry point and how the foreign body is affecting the wall of that organ.
assume that in the radiology department you take a CXR at 180cm using 100kV and 2mAs and then on the word you need to decrease your SID to 90cm. How would you adjust your exposure factors?
180 squared divide by 90 squared= 4 (therefore divide the mAs by 4). this will give you an mAs of 0.5. But you cant use 0.5 because the lowest mAs you can use is 1. Therefore we will lower the kVp by 10 to compensate for it. So it would be 90kV-1mAs OR 80kV for 2mAs. We would choose to use 90kV and 1mAs for ALARA.
