What is the main purpose of using a grid in radiography?
To reduce scatter radiation and improve image contrast.
What happens to your technique (mAs or kVp) when a grid is added?
The mAs (or sometimes kVp) must be increased to maintain image brightness due to the loss of scatter and some primary radiation.
Name two possible consequences of improper grid use:
Grid cutoff
Decreased image quality (contrast or exposure errors)
What type of grid is designed to match beam divergence?
Focused grid
What causes the Moiré effect?
When a stationary grid is used with a digital image receptor and the grid lines align with the scanning frequency of the system.
Moire Effect, Describe one method to prevent it:
Use a high-frequency grid or a moving grid (reciprocating Bucky system).
What does Moiré effect look like on an image?
Wavy, zebra-like or bar patterns over the image.
What is the purpose of beam restriction?
To reduce patient dose and scatter radiation, improving image quality.
Which beam restriction device allows the most flexibility?
Collimator (variable aperture)
Proper collimation helps reduce: (Circle one)
Patient dose and scatter
What does the air-gap technique help reduce?
Scatter radiation reaching the image receptor.
What is a downside to using the air-gap technique?
Increased magnification and potential for image blur.
What shielding device is used to protect reproductive organs?
Gonadal shielding
What is the benefit of using a technique chart?
Provides consistent, repeatable exposure techniques and reduces repeat exams.
How does a fixed kVp chart differ from a variable kVp chart?
Fixed kVp uses consistent kVp and varies mAs with part thickness; variable kVp changes kVp with part thickness and uses a fixed mAs.
Why is proper detector selection important when using AEC?
Selecting the wrong detector can lead to overexposure or underexposure, compromising image quality
What does the input phosphor convert?
X-rays to light
What component emits electrons in the image intensifier?
Photocathode
What does ABC stand for and what does it do?
Automatic Brightness Control – adjusts technique factors automatically to maintain consistent image brightness.
What is the main source of occupational exposure during fluoroscopy?
Scatter radiation from the patient
Name two protective devices used during fluoroscopy:
Lead apron
Thyroid shield (or lead gloves, protective barriers)
Where should the technologist stand to receive the least scatter?
On the side of the image intensifier (away from the x-ray tube), as far from the patient as possible.
Input Phosphor →
c) Converts x-rays to light
Photocathode →
b) Converts light to electrons
-
Chapter 142
-
Chapter 2 - 132
-
Chapter 2 - 234
-
Chapter 3 - 134
-
Chapter 3 - 234
-
Chapters 4 - 134
-
Chapter 4 - 234
-
Chapter 4 - 333
-
Chapter 5 - 150
-
Chapter 6 - 134
-
Chapter 6 - 233
-
Ch 754
-
Ch 9 - 02 - film screen imaging34
-
Ch 857
-
Ch 9 - 01 - film screen imaging35
-
Ch 10 - 01 - Flouroscopy39
-
Ch 10 - 02 - Fluoroscopy39
-
Josi Study Guide33
-
Useful Info1
