PHYSICS Test #5: Chapters 28, 29, 38, 39, 43

Performs all the arithmetic calculations and logic functions required to solve a problem.

Arithmetic/logic unit (ALU)

Describes the ability of a machine to make decisions based on logic functions such as "do," "if then," and "if else."

Artificial intelligence (AI)

For radiographers, it is important to understand _______________________ notation.

Power of 2

Three types of LANs with which radiographers should be familiar:

1. PACS (Picture Archiving and Communication System) 2. RIS (Radiology Information System) 3. HIS (Hospital Information System)

List the four main sectors of primary memory:

1. Program storage 2. Working or scratch-pad storage 3. Temporary input storage 4. Temporary output storage

What are the three different general ways that post-processing parameters can be modified?

1. Selecting a different procedural processing algorithm 2. Windowing 3. Applying special processing features

By using base ____ notation rather than a base ____ numbering system, binary code allows all data to be reduced to two values or bits, one and zero.

2; 10

What is the spatial frequency for an image with 0.1 mm pixels?

5 LP/mm (line pairs per millimeter)

The control unit and the arithmetic/logic unit both operate on information and data retrieved from a:

Primary memory storage system

What type of image viewing station is likely to be placed in an emergency room?

A display station

What type of transformer must be used for regular electrical power coming into a computer?

A step-down transformer

When compared to conventional film-screen radiography, digital radiography exhibits __________________. A. Wider exposure latitude B. Lower contrast C. Superior detail D. Greater luminence

A. Wider exposure latitude

Mathematically, the __________ essentially rounds out numbers to discrete values, thus reducing the volume of data to a dynamic range which the computer can manage.

ADC

What code was the first standardization of intermediate computer languages which provided compatibility between different manufacturers?

ASCII

Each _________________ in computer memory stores one byte of data.

Address

A concise set of instructions for a single, specific task performed by a computer.

Algorithm

The brightness of a pixel in the displayed electronic image is a function of the electric ______________ applied to that segment of the monitor screen.

Voltage

Data in which its units are infinitely divisible.

Analog

Data which can have any value, without limitation on its number of decimal places is ______________ data.

Analog

Information on a continuous spectrum.

Analog

Mathematically, the term ________________ means precisely proportional.

Analog

Data presented in continuous form, such that its presentation is precisely proportional to its actual magnitude.

Analog data

The various intensities of the x-rays that strike the image receptor can have any value and therefore constitute ______________________________.

Analog information

Data transmission can be in either __________________________ form.

Analog or digital

All image data must be converted into digital form by the ________________________________________ before being passed along to any computerized portion of the equipment.

Analog-to-digital converter (ADC)

Type of processing for computer data which refers to the method used when large amounts of data must be processed and only a few operations need to be executed on it. After the program, data, and control statements are entered, the user may leave while the computer performs these operations.

Batch

Bit is an acronym for ______________________.

Binary digits

The unit for the binary number system is one __________, an acronym for "binary digit."

Bit

A __________ consists of eight bits and is sufficient enough to create a single character.

Byte

The unit for measuring storage capacity is one ____________.

Byte

The larger the number of pixels in an image matrix, the _______________________. A. Greater the number of gray shades in the image B. Shorter acquisition time C. Greater the resolution D. Better the selfie

C. Greater the resolution

Performs data manipulation in the computer and tells the computer how to carry out software instructions.

Central processing unit (CPU)

The part of a computer that interprets and executes instructions is called the:

Central processing unit (CPU)

For CR, the scanning aperture is ______________ in shape.

Circular

Since DR uses hardware dexels, _______________ of the x-ray beam becomes analogous to the scanning function in digitizing an image.

Collimation

For communication to take place between all machines, both hardware and software components must be ________________________, that is, they must operate on the same physical principles and use the same basic languages and codes.

Compatible

Any machine that can perform mathematical computations, manipulate information, make decisions and interact accurately and quickly.

Computer

Computer software refers to all the instructions given to the hardware of the computer in order to carry out tasks, which is written in higher-level codes called:

Computer languages

A collection of hundreds or thousands of algorithms, each of which instructs the computer how to perform a single specific task.

Computer program

A collection of many hundreds or even thousands of interrelated algorithms which allow the user to perform a general application.

Computer program

Refers to all the instructions given to the hardware of the computer in order to carry out tasks, which is written in higher-level codes.

Computer software

Digital radiographic imaging became feasible when the exponential increase in the power of ___________________ brought contrast enhancement capabilities up to an overwhelming level.

Computers

Which portion of the CPU directs the flow of data between the ALU, primary memory, and input and output devices?

Control Unit

Coordinates the operations of the entire computer according to the instructions of the primary memory; programmed to select these instructions in proper order, interpret them, and relay commands between the primary memory and the arithmetic/logic unit.

Control unit

Directs the flow of data between the primary memory and the arithmetic/logic unit, as well as between input devices, the CPU, and output devices.

Control unit

Which of the following cannot be transmitted through PACS? A. Radiographs that have been scanned by a film digitizer B. Digitally reconstructed images such as CT or MRI C. Digital projection images D. Analog angiography images

D. Analog angiography images

Which of the following would result in a displayed digital image which is brighter? A. Increased window level B. Decreased window width C. Increased window width D. Decreased window level

D. Decreased window level

Data in which its units are defined so that the number of decimal places is limited.

Digital

Discrete information.

Digital

Changing the window level from 80 to 300 causes the image to become ________________.

Darker

As the display field of view is increased in size, spatial resolution (sharpness) does what?

Decreases

What is the formula for the computer file size required for a medical image?

File size X matrix size X bit depth

A communications network that is usually publicly or commercially owned and uses transmission services provided by common carriers such as phone or cable companies.

WAN

Data presented on a discrete scale, a scale made up of separated, distinct parts. How small these parts are limits the degree to which measurements can be subdivided.

Digital data

For a _____________________________________, the values of the x-rays that strike the image receptor must be rounded out to the nearest allowable discrete unit so that the computer can manage them.

Digital imaging system

Which type of data is inherently less accurate?

Digitized

For a particular physical area, the matrix size of an image (by pixel count) is _______________ proportional to the spatial resolution or sharpness of the image.

Directly

Devices share one server, and typically, the system is privately owned.

LAN

PACS is an example of which type of communication network?

LAN

Each address in primary memory consists of how many bit storage units?

Eight

One byte consists of ______________ bits of information.

Eight

The ability of different computer systems to communicate with each other.

External compatibility

For each anatomical procedure, what two image qualities are preset within the procedural algorithms?

Gray scale (dynamic range) and brightness (gray level)

Teleradiology makes it possible for images to be sent ___________________________ for a specialist to collaborate with a radiologist, and for images stored at a hospital to be accessed almost instantly by doctors at their individual clinics.

Great distances

The ________________ of the computer consists of all the physical components, including input devices, the processing system, memory and storage devices, output devices and systems for communication.

Hardware

Performs a similar action as RIS, but for all of a patient's general medical files throughout all the hospital.

Hospital Information System (HIS)

The power of a computer is measured by:

How many millions of instructions per second (MIPS) it can process

Three things expressed in powers of 2:

Image storage capacity Dynamic range (gray scale) of the image Matrix size of the image

How is microprocessor speed measured?

In gigahertz or terahertz

The selection of a narrow window width will _________________.

Increase contrast in the image

Describes the connection between a computer or imaging machine and any of its peripherals, other computers or devices.

Interface

The ability of a single computer's peripherals and components to all work together is termed its __________________ compatibility.

Internal

The ability of a computer's own components and software to work together, including graphics and sound cards, modems, printers, and software programs.

Internal compatibility

Compatibility may be divided into two broad categories:

Internal compatibility and external compatibilty

Workstations should be located in an area where ambient _________________ is subdued.

Lighting

A computerized communications network generally contained within a single building or business.

Local area network (LAN)

Artificial intelligence is defined as the ability to perform ______________ functions such as "if then," and "if else."

Logic

For a particular image pixel, the higher the attenuation coefficient for x-rays in the corresponding voxel, the ________________ the gray level that will be assigned to the pixel by the imaging system.

Lower (lesser)

Most x-ray machine consoles are:

Microcomputers

The CPU for a typical PC is usually a single _____________________.

Microprocessor

MRI and CT scanners use:

Minicomputers

Receives digital information from the computer in the form of electronic signals of differing voltages. It converts these into analog audio signals, or distinct tones, for transmission over phone lines. This device can also perform the reverse upon receipt of the tones, turning them back into voltages that represent the data.

Modem

Provide the ability to transmit images and other data over phone lines or fiber optic lines. Direct memory access speeds up the display process through bypassing the CPU.

Modems

The word modem is an acronym for _________________________.

Modulator-Demodulator

Any single access point within a WAN or LAN is called a(n):

Node

The CPU for a mainframe computer may be large enough to:

Occupy its own separate cabinet

Type of processing for computer data in which transactions are processed immediately upon entering a command, and the user must be present at the terminal to execute the command.

On-line

The four general approaches to processing data on a computer:

On-line processing Batch processing Real-time processing Time-sharing

Four types of data processing:

On-line, batch, real-time, time-sharing

Facilitates access to and management of images for all the nodes in the RIS and HIS systems.

PACS

The specific type of LAN used for managing images within a radiology department is called a:

PACS

Used within a medical imaging department to make radiographs, CT and MRI scans, ultrasound and nuclear medicine images for a particular patient available at any node within the network.

PACS (Picture Archiving and Communication System)

The greatest efficiency of communication is achieved when these systems are compatible and fully integrated.

PACS, RIS, HIS

Pixels is an acronym for _______________________.

Picture elements

A small point in an image that has been assigned a gray shade or brightness level is a ________________.

Pixel

The set dynamic range for an imaging system must be much greater than the capability of the human eye in order to allow for __________________________ of the image.

Post-processing

Performs a similar action as PACS, but for a data base of written records and files on patients, making them accessible from different locations within the radiology department.

Radiology Information System (RIS)

As long as discrete units are smaller than a human can detect, ___________________________ is improved.

Read-out accuracy

Type of processing for computer data in which an array of processors work in parallel to perform a complex computation on a large amount of data at high speed.

Real-time

Radiographic imaging systems must use __________________________ to display images with quick access and manipulation capability.

Real-time data processing

This creates the illusion of instantaneous feedback or image display.

Real-time processing

What does RAID stand for?

Redundant Array of Independent Discs

Widely used in medical imaging, prevents the accidental loss of information by multiple, independent back-up storage.

Redundant Array of Independent Discs (RAID) System

The initial measurement of pixel values within an image field is called _______________.

Sampling

For CR and DR, the sampled voxels within the patient take on the shape of ________________________.

Squared tubes

Refers to any system which allows the remote transmission and viewing of radiographic images via modems over phone or cable lines.

Teleradiology

All CPU's may be divided into two basic components:

The control unit and the arithmetic/logic unit

What determines the MIPS of a computer?

The speed of the microprocessors

This type of processing is also common in medical imaging, particularly in the form of Picture Archiving and Communication Systems (PACS), which allow centralized patient files to be brought up at a number of different terminals.

Time-share processing

Type of processing for computer data that refers to the use of a large central computer that creates the illusion of serving several terminals simultaneously.

Time-sharing

Why may the actual dynamic range set for image reconstruction be less than the bit depth of the computer system?

To reduce image processing time

Function of the ADC.

To round out values of the x-rays that strike the image receptor to the nearest discrete unit so that the computer can manage the information

What does USB stand for?

Universal Serial Bus

A computerized communications network that extends to other businesses or locations that may be at great distances.

Wide area network (WAN)

The user-friendly "contrast" adjustment is exactly inverse to window _____________.

Width

In generic digital imaging terms, the average brightness level of the image is called:

Window level

In generic digital imaging terms, the range of the image gray scale is called:

Window width

The general term for making changes in the brightness and contrast of a digital image is __________________.

Windowing