CH 11 Computer Systems/Imaging Science

Computer science, handout, and CR/DR

Modern day computers use _________ to store information

silicon chips

Computer hardware includes the:

keyboard, central processing unit, motherboard

Which modality was the first to use the principle of digital imaging?

CT

The ________ is an example of computer input hardware.

Mouse and keyboard

The __________ controls data transfer between the main memory and the input and output hardware

central processing unit

The active storage of a computer is stored in _________ chips.

DRAM, SRAM, and ROM

A hard disk, optical disk or jump drives are used to:

archive files

The ________ represents zero or one

bit

In computer language _________ is a "word."

2 bytes

MAC-OS, Windows, and Unix are three different _____ systems.

operating

A computer first uses its __________ program when it is turned on

bootstrap

When a computer is _________ it processes data without human input or intervention

batch processing

Automatic bank tellers are _____ computer systems.

online

In computerized medical imaging equipment, such as CT scanners, the computers processing are?

real-time

Large research facilities use _________ systems to accommodate many users.

time-sharing

Computers use two types of information:

Operating instructions and collected facts

Computers operate from a __________ language

binary machine

Each binary number is called a

bit

8 bits is a

byte

When the main power to the computer is turned off, ________ is erased.

RAM

When the main power to the computer is turned off, ______ is maintained.

ROM

Which system of conductors connects the various components of a computer system?

a bus

Digital imaging techniques are always applied to:

CT, MRI, and US

In digital radiography, the brightness of the image is determined by:

pixel values

Digital imaging could only be developed after advances were made in:

Photostimulable phosphors and microprocessors

Resolution is improved with increased ___________ in digital radiography

matrix size

The dynamic range determines the degree of ________ in the image

contrast resolution

The size of a pixel is measured in:

microns

Multiple numeric values divided into an array of small elements capable of being processed is the definition of ________ images

digital

Digital image quality is improved with:
1. Larger size matrix
2. Larger size pixels
3. Smaller size matrix
4. Smaller size pixels

Larger size matrix and smaller size pixels

If the field of view is increased for a fixed matrix:

a pixel size is increased

If the matrix is increased for a given FOV:

Spatial resolution is increased

The number of bits per pixel is known as bit:

depth

Digital images are made of discrete picture elements called

pixels

Which of the following is not an output device?
1. Laser film
2. Printer
3. Ultrasound transducer
4. CRT screen

ultrasound transducer

The _________ of the CPU is what carries out the arithmetic operations to execute a program

ALU

A modum serves as

both input and output

Soft copy viewing means that the image is being viewed

at a computer

The communication standard for information sharing between PACS and imaging modalities is the

DICOM

The sequence of instructions developed by a software programmer is called a

computer program

A series of instructions that organizes the course of date through the computer to the solution of a particular problem

Operating system

Programs written in a higher level language expressly to carry out some user function

application programs

A computer program that recognizes symbolic instructions such as subtract, load, and print and translates them into the corresponding binary code

Assembler

Computer programs that translate an application program from its high level language into a form that is accepted directly by the computer

compilers and interpreters

The oldest language for scientific, engineering and mathematical problems is

FORTRAN

Problems that can be expressed in terms of formulas and equations are called

algorithms

A step by step process used to solve a problem is an

algorithm

An area xray beam intercepted by a photostimulable phosphor plate or direct capture solid state device is 

DR

Digital images are a

numeric representation of the xray intensities that are transmitted through the patient

The range of values over which a computer system can respond (its capacity/software type), and the number of shades of gray that it can respond is called the

dynamic range

Xray ______ is the phenomenon of xrays being emitted from a material that is excited with gamma rays or xrays. It is the instantaneous emission of light following photon absorption

fluorescence

The general term to describe the emission of light

luminescence

The delayed emission of light following photon absorption. Can be prompt or later

phosphorescence

_____ noise decreases image contrast

Increased

The measurement of radiation energy in joules absorbed in a unit of air (kg). Measures amount of radiation incident on the IR for that exposure

air kerma value

Determines whether an image has been under or over exposed

deviation index

This number is directly proportional to radiation striking the flim

exposure index

This number is inversely proportional to radiation striking the flim

S#

The wide range of acceptance of exposure factors to produce an acceptable image

wide latitude

The process of modifying the pixel values based on mathematical formulas

Convolution (windowing)

The process of returning the pixel values to their original level by a reverse process

deconvolution

Bit ____ allows for representation of number of shades of gray the computer can display

Bit range

Involves the systematic application of highly complex mathematical formulas called algorithms

digital processing

The primary mathematical method used in the creation of computerized medical images and accomplishes transformation of extremely complex functions into separate but simpler functions

fourier transformation

Information stored in files for your computer to read is called

date

clumps of stored computer date that hold and store information that can be read by your computer is called

files

An ____ will assign a binary number to the analog date which the computer processor interprets

ADC (analog to digital converter)

A _____ converts digital data into analog signal

DAC (digital to analog converter)

The numerical value indicating the level of radiation exposure to the digital IR is the

Exposure indicator/ s number

A larger bit depth:

Increases the number of shades of gray

The pixel bit depth determines the image's

Contrast resolution

The greater the pixel bit depth, the _______________ the digitization of the analog signal, and the __________ the number of shades of gray available for image display.

More precise; greater

The window level controls

brightness

The window width controls

image contrast

The human eye can detect approximately 32 shades of gray, while a computer can detect or visualize up to

4096

Each cell of an image matrix is called a

pixel

An image matrix displays a dynamic range of values.

true

The ability of the detector to accurately capture the variety of photon intensities in the remnant radiation is:

dynamic range

Consists of many transistors and other electronic elements fused onto a chip

Integrated circuits (IC)

Places millions of circuit elements on a chip that measures less than 1cm

Very large scale integration (VLSI)

Computer recognized command that evaluates an intermediate result and performs subsequent computations in accordance with that result

Logic function

Device that converts digital information into analog information

modem

Series of instructions that organizes the course of data through the computer to solve a particular problem

operating system

Computer programs that translate an application program from its high level language into a form that is suitable for the assembler or into a form that is accepted directly by the computer

Compliers and interpreters

Programs written in a higher level language expressly to carry out some user function

application programs

Sequence of instructions developed by a software programmer

computer program

Term that refers to the output seen on a digital display deviceqq

soft copy

Multidisc drives are called

jukeboxes

An input/output device that uses a keyboard for input and a digital display device for output. Can be dumb or intelligent

Terminal

Another form of output device and are categorized by the manner in which the print mechanism physically contrasts the paper to print an image