Overview Flashcards
radiolucent
allows the passage of x rays
radiopaque
blocks the passage of x rays
interface
the place were two tissues with different densities meet
what is something that is radiolucent
air
what is something that is radiopaque
bone, metal
why is the density of a substance relevant to radiography
because different tissues have different densities, which creates variation of exposure and create interfaces
what are the five radiographic densities? how do they look on x ray
- Gas (black)
- Fat (grey)
- Fluid/soft tissue (grey)
- Bone (white)
- metal (white
when is it possible to see distinctions between substances on x ray
when there is an interface between the structures
silhouette sign
when there is no distinction bewteen tissues that should have an interface
identify 1-5
- air
- fat
- fluid
- bone
- metal
what happens to xrays as they pass through tissue
they are attunated a differenr rates
what happens when the object of a xray image is closer to the source? closer to the plate?
being close to the source will make the image blurry, close to the plate will make the image more clear
what are five benfits of digital imaging
- no x ray film cost
- no lost films
- no storage needed
- no one needs to go get films
- xrays are easy to manipulate
view
refers to the image as it is seen on a radiograph
position
the poster of the patient during the exam
projection
refers to the direction of the central beam
what are seven common views for xray
- PA
- AP
- lateral
- lordotic
- oblique
- lateal decubitus
- ap recumbent
what is the position of the patient in a PA? what is it useful for
the patient is standing facing the plate with the projection coming from behind
it defines the borders of the heart
what is the position of the patient in a AP? what is it useful for
standing with their back against the plate and the projection coming from in front
makes the heart borders less distinct
what position is the patient in during a lateral? how are they named
standing with one side against the plate and the projection coming from the other side
they are named by the side that is closest to the film
what is the position of the patient in for a lordotic xray? what is it useful for
standing AP with their back arched and upper back against the plate
the elevate the clavicles over the apices of the lungs and make them easier to see
what is the position of the patient in an oblique view? what are they useful for
a lateral xray with the patient slightly turned forward or backward
to see around the heart
what is the position of the patient in lateral decubitus? what is it useful for
an PA projection with the patient lying on their side
it can be used to look for free fluid in the chest as it settles to the down side
how are lateral decubitus xrays named
by the side that is lying down
T/F one view is sufficied for most radiography
false, two views at right angles to each other are suggested to get a better 3D idea
seven divisions of radiology
- diagnostics
- mammography
- ultrasound
- computed tomography
- magnetic resonance imaging
- nuclear medicine
- interventional radiology
what are the pros and cons of diagnostic radiology
pros: inexpensive, easily obtained
cons: limited range of densities, uses ionizing radiation
what is a common use for an abdominal x ray
looking for free air in the abdomen
what are three types of procedures found in diagnostic radiology
- barium studies
- genitourinary studies
- myelography
what are three examples of a barium study
- barium swallow
- barium enema
- small bowel follow through
mammography
a very accurate method of detecting breast masses using radiography
T/F an abnormal breast exam should have mammography and ultrasound
true
what is ultrasound most useful for? what are the pros?
obstetrics, renal function, spleen, liver, aorta
inexpensive and widely available with no ionizing radiation
what does a CT do
uses Xrays to make a 3D image
what are the best used for? what are the pros and cons?
bone imaging
pros: quick, painless, more information that xray
cons: expensive, lots of radiation
what is MRI best used for? what are the pros and cons?
soft tissue pathology
pros: can see soft tissue well
cons: expensive, magnetic objects are a hazard, need to lay still
what is MR arthography? what is used for
a new type of MRI that uses gadolinium injected into the joint
it is used to evaluate unstable or post operative joints
what is nuclear medicine
the adminstration of a radioisotope which emits gamma rays that are recorded
what is nuclear medicine used for
the diagnosis of cardiac, respiratory, neoplastic, infectious diseases
interventional radiology
trained xray techs performing specialized procedures with contrast imaging
what are some common procedures in interventional radiology
PIC lines, thoracentesis, paracentesis, biopsies, aneurysm coiling
why is it important to know the diagnosis before you order radiography
so you know what the best test is to look for the problem you want and not fishing to limit xray exposure
when is it appropriate to order an xray
when a physical exam can’t show you all you need to know
legality
what are four ways to assess the quality of a radiograph
- did you get what you ordered?
- are the films useful in evaluation
- is there adequate contrast
- are both joints visible on a long bone film
what are four ways a patient can affect test results
- age
- mental status
- physical limitations
- uncooperative or allergic to contrast
why is it important to provide history to the reading radiologist
so he can help provde with a more concise diagnosis
lag time
the time between when symptoms occur and when there are radiographic changes
