Question 1

Phototimer AEC detectors are usually exit-type devices because

Accepted Answer

Phototimer Automatic Exposure Control (AEC) detectors are typically positioned behind the image receptor to measure the amount of radiation that has passed through the patient and the image receptor. This allows the system to accurately control the exposure time based on the amount of radiation reaching the detectors, ensuring optimal image quality.

Question 2

When using AEC, the kVp

Accepted Answer

The kVp is set as appropriate for the study when using Automatic Exposure Control (AEC), as it is a parameter that needs to be manually selected by the technologist based on the type of examination and patient size. The AEC system then adjusts the exposure time to achieve the desired level of image density.

Question 3

The predetermined level of radiation exposure needed to terminate the exposure when using AEC is set by

Accepted Answer

C

Question 4

There is typically a configuration of at least ______ AEC detectors in place

Accepted Answer

There are typically at least 3 Automatic Exposure Control (AEC) detectors in place to allow for different sizes and types of exams, providing flexibility and ensuring optimal exposure for various imaging needs.

Question 5

An ionization chamber is a hollow cell that contains

Accepted Answer

An ionization chamber typically contains air, which becomes ionized when radiation passes through it, allowing the measurement of the ionization events.

Question 6

Using a lower mA station during an AEC examination results in

Accepted Answer

Using a lower mA station during an AEC examination increases the exposure time to achieve the necessary image density, as the automatic exposure control adjusts the time to compensate for the lower mA.

Question 7

The device that converts the light energy to an electrical signal is the

Accepted Answer

Photodiodes and photomultiplier tubes both convert light energy into electrical signals. Photodiodes do this by generating a photocurrent when light is absorbed, while photomultiplier tubes amplify this photocurrent, making them highly sensitive to light.

Question 8

The shortest exposure time that a radiographic tube with AEC can have is the

Accepted Answer

The minimum response time is the shortest exposure time that an Automatic Exposure Control (AEC) system can achieve. It is determined by the speed at which the AEC can detect the required amount of radiation and signal the x-ray generator to terminate the exposure.

Question 9

AEC controls the amount of radiation reaching the IR by controlling the

Accepted Answer

AEC (Automatic Exposure Control) primarily controls the time of exposure to ensure the correct amount of radiation reaches the image receptor.

Question 10

The two types of detectors used in AEC are

Accepted Answer

Phototimers and ionization chambers are the two types of detectors used in Automatic Exposure Control (AEC) systems in radiography to automatically control the amount of radiation exposure to achieve optimal image quality.

Question 11

These can be adjusted to increase or decrease the amount of radiation needed to terminate the exposure using AEC

Accepted Answer

Exposure adjustment allows the technologist to modify the amount of radiation needed to terminate the exposure when using Automatic Exposure Control (AEC).

Question 12

The actual amount of exposure used for an image when AEC is being used is the

Accepted Answer

The actual amount of exposure used for an image when Automatic Exposure Control (AEC) is being used is reflected in the mAs readout. This readout shows the actual milliampere-seconds used to achieve the desired exposure, as determined by the AEC system.

Question 13

The maximum length of time that an exposure lasts when using AEC is the

Accepted Answer

The maximum length of time that an exposure lasts when using Automatic Exposure Control (AEC) is determined by the back-up time. This is a safety feature designed to prevent overexposure to the patient by limiting the duration of the exposure in case the AEC system fails to terminate the exposure at the correct time.

Question 14

Once the electric charge from an AEC detector reaches a preset point

Accepted Answer

When the electric charge from an Automatic Exposure Control (AEC) detector reaches a preset point, it signals the radiographic system to terminate the exposure. This ensures the desired level of image density is achieved without overexposing the patient.

Question 15

The primary purpose of AEC is to

Accepted Answer

The primary purpose of Automatic Exposure Control (AEC) is to control the amount of radiation reaching the Image Receptor (IR) by automatically adjusting the exposure time.

Question 16

Using a higher kVp during an AEC examination results in

Accepted Answer

Using a higher kVp during an Automatic Exposure Control (AEC) examination results in a shorter exposure time because the higher energy photons are more likely to penetrate the patient and reach the detector, thus achieving the desired exposure level more quickly.

Question 17

Today's AEC system is most likely use a(n)

Accepted Answer

Ionization chambers are commonly used in modern Automatic Exposure Control (AEC) systems in radiography to measure the amount of radiation passing through the patient and terminate the exposure when the correct amount is reached.

Question 18

The original type of AEC detector was the

Accepted Answer

The original type of Automatic Exposure Control (AEC) detector was the phototimer, which uses the amount of light produced by the x-ray interaction with the fluorescent screen to terminate the exposure once the desired amount of radiation has been received.

Question 19

When the x-rays enter the ionization chamber

Accepted Answer

When x-rays enter an ionization chamber, they cause atoms to ionize, meaning the atoms lose electrons and become positively charged ions. This process involves atoms becoming ions (A), giving up electrons (B), and the resulting free electrons and positive ions moving under an electric field to create an electric current (C). Therefore, all of the statements are correct in describing what happens in an ionization chamber when exposed to x-rays.

Question 20

Ionization chamber AEC detectors are entrance-type devices because the x-rays must

Accepted Answer

Ionization chamber Automatic Exposure Control (AEC) detectors are considered entrance-type devices because they are positioned in such a way that the x-rays enter the detector before they reach the image receptor (IR). This positioning allows the AEC system to measure the x-ray exposure almost directly as it enters the patient, ensuring accurate exposure control.

Quiz 13: Exposure Technique Selection