Rdiographic Interpretation Flashcards
What does the photoelectric effect depend on?
The cube of the atomic number
What does absorption depend on?
Absorption=density and the cube of the atomic number
What is the Compton effect and what does it depend on?
It is the scatter of the X-ray and is affected by the density
What are the five different radiopacities?
Gas fat soft tissue or fluid mineral metallic
How can depth perception be reconstructed?
By taking more than one view you will get a better idea of what is going on in a 2D image
What is border effacement?
Two structures of the same opacities overlap and so their margins cannot be identified. The borders are effeced
What are the steps for radio graphic interpretation?
Viewing conditions-dark, evaluate the radio graphic quality, the roentgen signs, examine systematically, apply knowledge of normal anatomy, form a differential list to explain the changes.
How do you orientate the radiograph?
Based on human patient standing infront of the clinician. So patient right to image left and then patient rostral/cranial to image left
Why are the ideal viewing conditions?
Quiet, dark, block out extra light, bright light box, enough view boxes, uninterrupted.
What factors do you use to determine radiographic quality?
Exposure, patient positioning(not rotated), phase if respiration-inspiratory for lungs and exploratory for abdomen due to displacement of the diaphragm, patient factors- fat, breed, age and collimation
What can happen if exposure is not right?
Kv and mAs is too low= overexposed
Kv and mAs too high= underexposed
Motion e.g. Heart beat etc so you decrease the motion time to decrease artefacts
What does Kv and mAs mean?
Penetrating power and number of X-rays
What is collimation?
Centring of the patient to concentrate the beam of one specific area
What are the rontgen signs?
Size, shape, number, location, margination, radiopacity
What are the rontgen signs used for?
Interpretation of the radiograph; referral for surgery and for diagnosis
How can you evaluate the radiograph?
Organ approach, area approach, evaluate the whole radiograph not just the organ that is thought to be the problem
Why is body condition important?
The subcutaneous fat will reduce the image quality due to increased opacity from the fat
What can make interpretation difficult?
New bone growth, old injury, inflammation and chronic fractures
What three things make up radiographic geometry?
Magnification, penumbra, distortion
What does magnification of the radiograph?
Enlargement of the radiographic image of an object relative to its actual size, it increases the film subject distance
What is the relationship between magnification and penumbra?
The width of the penumbra increases with increased magnification
What is distortion?
Mis representation of the true show of an object
What is summation?
Superimposition of structure in different planes and the resultant image is the summation of the opacities.
