Principles of Interpretation Flashcards
What are 3 things imaging is designed to reduce or eliminate uncertainty about?
- A diagnosis
- Extent of disease
- Performing a treatment
What are 2 things affecting accuracy?
- Search pattern
- Separating fact from fake-outs
What are 4 things to consider when looking at a radiograph?
- Quiet dim environment
- Not in a hurry
- Be familiar with patient
- Know the question that is being asked
How should radiographs be looked at?
Have an organized scan route.
Where are the most over-looked lesions in the thoracic often located?
Bones/ribs
What are 7 things to check in the thorax?
- Heart
- Pulmonary vessels
- Lung
- Pleura
- Mediastinum
- Trachea
- Bones
What are 10 things to check in the thorax?
- Stomach
- Small Intestine
- Colon
- Liver
- Spleen
- Kidneys
- Bladder
- Peritoneum
- Retroperitoneum
- Bones
When examining a limb, what is it helpful to do?
Radiograph the opposite limb.
What are the 5 opacities in order from least to most opaque?
- Air
- Fat
- Water
- Bone
- Metal
Does radiographic density correlate to radiopacity or radiolucency?
Radiopacity
Does optical density correlate with radiopacity or radiolucency?
Radiolucency
As atomic number increases, does opacity increase or decrease?
Increase
Why are opacities important?
They allow different structures to be differentiated and identified.
Are radiographs 2D or 3D?
2D
What are 3 examples of dimensional limitations of radiographs?
- Magnification/distortion
- Loss of depth perception
- Superimposition & summation shadows
Magnification will cause an image to be what?
Larger and sharper
What is distortion?
Special case of unequal magnification.
Distortion can make a bone look what?
Shorter
When a structure appears in an unexpected location and is misinterpreted as a lesion it is known as what?
Superimposition
What shape are most metastatic lung lesions?
Round
A special case of superimposition where overlapping structures create a summation opacity that is not really present in the patient is known as what?
Summation Sign
The effacement (loss of visualization) of the border of 2 structures of the same radiographic opacity that are in contact is known as what?
Silhouette Sign
With pleural effusion, can the heart be seen better in a DV or VD view?
VD
How do you name radiographs?
- Point of entrance to point of exit
- Use correct anatomic terminology
How is the cranial/proximal portion of the patient always oriented in a radiograph?
To the top.
How is the head/trunk of the patient always oriented in a radiograph?
Patient left on viewer right.
T/F: There is no convention regarding medial vs lateral on view in regards to extremities.
True
A left-right lateral view means the patient is in what type of recumbency?
Right lateral recumbency
A right-left lateral view means the patient is in what type of recumbency?
Left lateral recumbency
What are 4 things to consider when interpreting a radiograph?
- Signalment & history
- Physical examination
- Is the radiograph normal
- Describing any abnormalities
What are the 6 Roentgen signs?
- Size
- Shape
- Number
- Location
- Margination
- Opacity
What are Roentgen signs?
Terms used to describe lesions in radiographs.
