Medical Imaging Computer Science

Abacus

The earliest calculating tool, invented thousands of years ago in China and is still used in some parts of Asia.

Blaise Pascal and Gottfried Leibniz

Two mathematicians in 17th century who built Mechanical Calculators that could perform the FOUR BASIC ARITHMETIC FUNCTIONS of addition, subtraction, multiplication, and division.

Charles Babbage

Designed an analytical engine that performed general calculations automatically in 1842.

Herman Hollerith

designed a tabulating machine to record census data in 1890.

John Atansoff and Clifford Berry

designed and built the first electronic digital computer in 1939.

Colossus

Built by British, first fully operational working computer designed to crack encrypted German military codes in December 1943.

Automatic Sequence Controlled Calculator

(ASCC) / Mark I

The frst general-purpose modern computer, developed in 1944 at Harvard University.

ENIAC (Electronic Numerical Integrator and Calculator)

The first general-purpose electronic computer, developed in 1946 at the University of Pennsylvania by J. Presper Eckert and John Mauchly

transistor

is an electronic switch that alternately allows

or does not allow electronic signals to pass

William Shockley

developed the transistor in 1948 at the Bell

Telephone Laboratories.

Transistor

It made possible the development of the “stored program” computers.

UNIVAC (UNIVersal Automatic Computer)

The first commercially successful general purpose, stored program electronic digital computer in 1951. Eckert and Mauchly of the Sperry-Rand Corporation.

First-generation computers

vacuum tube devices (1939–1958)

Second-generation computers

individually packaged transistors in 1958.

Third-generation computers

Integrated circuits (ICs), which consist of many transistors and other electronic elements fused onto a chip—a tiny piece of semiconductor material, usually silicon in 1964.

microprocessor

developed in 1971 by Ted Hoff of Intel Corporation

fourth generation of computers

extension of the third generation and incorporated large-scale integration (LSI), then later replaced by very large-scale integration (VLSI), which places millions of circuit elements on a chip that measures less than 1 cm in 1975.

computer

refers to any general-purpose, stored-program electronic digital computer

Analog

refers to a continuously varying quantity; a digital system uses only two values that vary discretely through coding.

Principal parts of computer

hardware and software

hardware

everything about the computer that is visible—the physical components of the system that include the various input and output devices

Hardware

Operations that include input processing, memory, storage, output, and communications.

software

the computer programs that tell the hardware what to do and how to store and manipulate data.

Computer Language

To give a computer instructions on how to store and manipulate data

binary system

All computers languages translate what the user inputs into series of two digits, 0 and 1.

decimal system

10 digits (0–9) in the system is used

Latin for “finger” or toe

digit

A timeline showing the evolution of today’s computer.

Power of 2 notation

Is used in radiologic imaging to describe image size, image dynamic range (shades of gray), and image storage capacity.

Digital images

made of discrete picture elements, pixels, arranged in a matrix.

computed tomography (CT) and magnetic resonance imaging (MRI) images measurement

256 × 256 (2⁸) to 1024 × 1024 (2¹⁰)

digital fluoroscopy image measurement

1024 × 1024 matrix

digital radiography and digital mammography Matrix sizes

2048 × 2048 (2¹¹) and 4096 × 4096 (2¹²)

bit

a single binary digit, 0 or 1

bytes

Bits grouped into bunches of eight

binary digits

Are to encode and is to translate from ordinary characters to computer-compatible characters

One kilobyte (kB)

equal to 1024 bytes

kilo in bytes

represents 2¹⁰ or 1024

The computers typically used in radiology

departments have capacities measured in

gigabytes (GB)

How many bits can be stored on a 64-kB

chip?

542,288 bits

word

Constitutes to two bytes equal to 16 bits

“nibble”

half a byte equal to 4 bits

“chomp”

two words equal to 32 bits

computer program

The sequence of instructions developed by a software programmer. Used to distinguish two classifications of computer programs: systems software and application programs.

Systems software

programs that make it easy for the user to operate a computer to its best advantage.

Application programs

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

Computer programs

the software of the computer.

operating system

series of instructions that organizes the course of data through the computer to the solution of a particular problem. It makes the computer’s resources available to application programs.

assembler

computer program that recognizes symbolic instructions such as “subtract (SUB),” “load (LD),” and “print (PT)” and translates them into the corresponding binary code

Assembly

the translation of a program written in symbolic, machine-oriented instructions into machine language instructions

Compilers and interpreters

are computer programs that translate an application program from its high-level language, such as Java, BASIC, C++, or Pascal, into a form that is suitable for the assembler or into a form that is accepted directly by the computer

Interpreters

make program development easier because they are interactive.

Compiled programs

run faster because they create a separate machine language program.

applications programs

Computer programs that are written by a computer manufacturer, by a software manufacturer, or by the users themselves to guide the computer to perform a specific task

Application programs

allow users to print mailing lists, complete income tax forms, evaluate financial statements, or reconstruct images from x-ray transmission patterns.

Application programs

They are written in one of many high-level computer languages and then are translated through an interpreter or a compiler into a corresponding machine language program that subsequently is executed by the computer

The sequence of software manipulations required to complete an operation.

bootstrap

Capable of transferring other necessary programs off the disc and into the computer memory. loads the operating system into primary memory, which in turn controls all subsequent operations.

hexadecimal number system

used by assembly level applications

assembly language

acts as a midpoint between the computer’s binary system and the user’s human language instructions.

hexadecimal numbers

Each of these symbols is used to represent a binary number or, more specifically, a set of four bits.

In hexadecimal numbers, a byte is equal to

two hexadecimal numbers. Which means each of these symbols is equal to 4 bits

The set of hexadecimal numbers corresponds to the binary numbers for 0 to 15

FORTRAN (FORmula TRANslation)

The oldest language for scientific, engineering, and mathematical problem, developed in 1956 by IBM

algorithms

Problems that can be expressed in terms of formulas and equations

BASIC (Beginners All-purpose Symbolic Instruction Code)

Developed at Dartmouth College in 1964 as a first language for students

BASIC

contains a powerful arithmetic facility, several editing features, a library of common mathematical functions, and simple input and output procedures.

COBOL (COmmon Business Oriented Language)

One high-level, procedure-oriented language designed for coding business data processing problems. Provides extensive file-handling, editing, and report generating capabilities for the user

Pascal

high-level, general purpose programming language that was developed in 1971 by Nicklaus Wirth of the Federal Institute of Technology at Zürich, Switzerland. A general-purpose programming language is one that can be put to many different application

C

considered by many to be the first modern “programmer’s language.” It was designed, implemented, and developed by real working programmers and reflects the way they approached the job of programming.

C+ +

response to the need to manage greater complexity, developed by Bjarne Stroustrup in 1980.

contains the entire C language, as well as many additions designed to support object-oriented programming (OOP)

OOP

a method of dividing up parts of the program into groups, or objects, with related data and applications, in the same way that a book is broken into chapters and subheadings to make it more readable.

Visual programming languages

designed specifically for the creation

of Windows applications.

macros

used to carry out user defined functions or a series of functions in the application. The user can create a command to manipulate a series of data by performing a specific series of steps.

recording

process of designing a macro

LOGO

language that was designed for children

ADA

official language approved by the U.S. Department of Defense for software development. It is used principally for military applications and artificial intelligence.

Java

developed in 1995, became very useful in web application programming as well as application software

HTML (HyperText Markup Language)

predominant language used to format web pages.

central processing unit (CPU)

primary element that allows the computer to manipulate data and carry out software instructions

microprocessor

In microcomputers, they are the CPU

control unit and an arithmetic/logic unit (ALU)

Computer's CPU components

bus

an electrical conductor that connects the two components and all other components

processor

The electronic circuitry that does the actual computations and the memory that supports it

Main memory

the working storage of a computer.

RAM

The contents are temporary, capacity usually is expressed as megabytes (MB), gigabytes (GB), or terabytes (TB), referring to millions, billions, or trillions of characters stored.

two types of RAM

dynamic RAM (DRAM) and static RAM (SRAM

DRAM

The memory is not saved after turning off the power

SRAM

retains its memory even if power to the computer is lost

registers

Special high-speed circuitry areas found in the control unit and the ALU. hold information that will be used immediately.

Read-only memory (ROM)

contains information supplied by the manufacturer, called firmware that cannot be written on or erased.

PROM, EPROM, and EEPROM

Three variations of ROM chips used in special

situations

PROM (programmable read-only memory)

blank chips that a user, with special equipment, can write programs to. After the program is written, it cannot be erased.

EPROM (erasable programmable read-only memory)

contents are erasable with the use of a special device that exposes the chip to ultraviolet light.

EEPROM (electronically erasable programmable read-only memory)

can be reprogrammed with the use of special electron impulses.

motherboard or system board

the main circuitboard in a system unit. This board contains the microprocessor, any coprocessor chips, RAM chips, ROMchips, othertypes of memory, and expansion slots, which allow additional circuit boards to be added

Storage

archival form of memory

terminal

input/output device that uses a keyboard for input and a display screen for output.

dumb terminal

cannot do any processing on its own; it is used only to input data or receive data from a main or host computer

intelligent terminal

has built-in processing capability and RAM but does not have its own storage capacity.