The Basics of Digital Imaging
Ambient light may cause which of the following?
Glare on the monitor
Approximately half of the x-ray energy is "stored" in the phosphor layer of the image plate. What happens to the other half of the x-ray energy?
It is emitted as visible light
Which of the following types of film digitizers uses a photomultiplier tube to detect the transmitted light?
Laser-Based
Which of the following is true concerning indirect digital radiography?
Less exposure to the patient and less spatial resolution
What is the shape of the characteristic curve of a CR image plate?
Linear
Spatial resolution in digital imaging is determined by which of the following?
Matrix size and the size of the field of view.
In a network, each cable connects to which of the following?
Network Interface Card
What is the technical name for an image place?
Photostimulable phosphor plate
PACS stands for:
Picture Archiving and Communication System
RIS stands for:
Radiology Information System
Which of the following temporarily stores data in the computer?
Random Access Memory
What does the CR reader use to release the energy stored in the image plate?
Red visible light
What does the acronym R.A.I.D. stand for?
Redundant Array of Independent Disks
If two computers have different size Ethernet cards, what device is needed so they can communicate?
Router
How small of an object that can be recorded, its accuracy and clarity defines which of the following?
Spatial resolution
Most networks use which of the following protocols to communicate with each other?
TCP/IP
Visually, dynamic range refers to which of the following?
The number of shades of gray that can be represented.
When referring to digital imaging, what does the term digital mean?
Using numbers to compute images.
Which of the following changes the dynamic range of a digital image?
Window Width
How much secondary memory would it take to store a 512 x 512 CT image?
0.52MB
Which of the following devices could be used for archiving digital images?
1, 2, & 3 Magnetic Disks Magnetic Tapes Optical Disks
How many individual detectors will a typical flat-panel detector have in its matrix of detectors?
9 million
A well-managed PACS should be up and running _________ of the time.
99%
The CPU contains which of the following?
A control unit
What is the definition of amorphous?
A noncrystalline state of an otherwise crystalline material
What does it mean to direct capture a digital image?
All the digital data is sent directly from the modality to the PACS
What is the purpose of a thin-film transistor in a flat panel detector?
Allows the active readout of the charge stored in the capacitor
_______ releases electrons when struck by light photons and ________ releases electrons when struck by x-rays.
Amorphous silicon, amorphous selenium
Which of the following refers to adding text to a digital image?
Annotate
Which of the following terms DOES NOT fit with the others?
Application Software
Which of the following terms is used to describe long-term storage of digital images and documents?
Archive
Computers operate using a binary machine language. This language uses binary digits to compute data. A binary digit is referred to as a what?
Bit
Which of the following is not an I/O device employed in digital imaging?
CPU
Copper cables used to network computers are referred to as:
Category 5 or CAT5
What does CCD stand for?
Charged-Coupled Device
What is the major difference between computed radiography and conventional film-screen radiography?
Computed radiography has greater exposure latitude
Which of the following is a universal standard that allows various digital imaging devices to work together within a network no matter who the manufacturer?
DICOM
Which of the following modalities is not directly captured by PACS?
Digital Fluoroscopy
A hospital's plan to periodically backup archived files is known as what?
Disaster Recovery Plan
Which of the following allows a radiologist to rapidly move from one digital image to another?
Dynamic Spatial Display