(a)   determines the range of brilliancies within the displayed image. Bistable images, in which only black and white appear, are high contrast

(a)   determines the brilliance of the displayed image

The (a)   changes the format data

The (a)   translates the information from the spoke format into the video format

(a)   can have a unlimited, continuous range of values

• Infinite non-discrete numbers.

• Continuous spectrum

• Proportionate (anywhere between maximum and minimum handled by the system)

(a)   are associated with computer devices. Only have discrete value

Real world

Unlimited # of choices

Continuous values

(a)  

Computer world

Limited choices

Discrete values

(a)  

• Discrete numbers.

• Computerized.

• Limited options

In the digital format, resolution (a)   to bit-memory depth

A funnel shaped vacuum tube with an electron gun located within its smaller end

(a)  

The larger end of the tube contains a dielectric matrix or silicon wafer

(a)  

Stored charges on the silicon wafer dissipate over time

(a)  

Caused by switching between read and write modes

(a)  

Picture quality depends on many factors including length of use, room temperature, and humidify

(a)  

Image degrades as the device ages

(a)  

Funnel-shaped vacuum tube electrons  dielectric matrix (silicon wafer) or picture formed of millions of tiny dots (electron buckets)

(a)  

(a)   scan converters use computer technology to convert images into numbers, a process called digitizing

Consistent gray scale quality throughout the image

(a)  

Does not fade or drift

(a)  

Not affected by age or heavy use

(a)  

Nearly instant processing

(a)  

Error-fee

(a)  

Computerized

Digitalizing (0,1)

Processed image on screen

(a)  

• Scan converters are also called:

• Keep in mind that scan converters DO NOT DISPLAY the information; instead, they (a)   it and allow future processing in order to display the information

From the term picture element, the (a)   is the smallest building block of a digital picture

(a)   stores data as  numbers.

uses  zero “0” and one  “1”

(a)  

Echoes from receiver are assigned a number.

(a)  

• The digital memory contains a (a)   divided into squares called “pixels

• The digital memory contains a “matrix” divided into squares called (a)  

• A (a)   is a picture element.

• Smallest element of a digital picture

• A (a)   is a single shade of gray.

The __ pixels in the memory, the __ the memory spatial resolution

(a)  

The number of picture elements per inch

(a)  

Higher pixel density is achieved with (a)   pixels

Larger pixels = (a)   pixel density, worse quality image

A (a)   is a bistable having a value of either 0 or 1

A (a)   is a group of eight bits of computer memory such as 10011111

A (a)   of computer memory consists of two bytes or 16 bits

More bits per pixel = more shades of gray and improved (a)  

• Single (a)   is able to store only one of two numbers per echo:

The system must have (a)   than one matrix.

Each matrix of squared pixels can be imagined as being layered (a)  

Each matrix contains pixels which in time contains (a)   (1, 0).

Each single number is called a binary digit or a (a)  

1 byte = (a)   bits of data

Eight matrixes allow _-bit storage units.

(a)  

512 x 512 pixels

8-bits storage unit

(a)  

TWO BYTES (16 BITS) = A (a)   of Computer Memory

• The memory-bit depth (number of matrixes) determines the (a)   resolution and how many shades of gray in the image.

Memory bit depth determines the __ __

(a)  

• The more bits in the memory, the (a)   the contrast resolution.

Echo amplitude comes from the (a)  

Position measurements are performed (a)  

Are stored in the memory as numbers

(a)  

• (a)   signals are converted to binary numbers in analog-to-digital converters and stored in a bit-memory.

• Decimal numbers are based on 10ⁿ, while (a)   have a base of 2ⁿ

• Each analog signal is converted from a continuously variable voltage to a binary number by mean of the analog-to-digital scan converter (ADC)

Number of bits used as a group.

(a)  

Several bits used to increase configurations

(a)  

• Most modern memory systems cast (a)   shades of gray (8-bit memory).

Any manipulation before storage

(a)  

Any manipulation after storage

(a)  

•       BEFORE MEMORY

• TGC, compression, write magnification, persistence, spatial compounding, edge enhancement, fill-in interpolation

• AFTER MEMORY

• Changes after freezing image, B/W inversion, read magnification, contrast variation, 3D rendering

With (a)   , the sonographer can improve anatomic detail by enlarging a portion of an image to fill the entire screen

(a)   magnification occurs AFTER the image data is stored in the scan converter

(a)   magnification is characterized by the number of pixels or scan lines in the magnified image, is the same as in the original image

With (a)   magnification, spatial resolution does not change because the number of pixels in the ROI is unchanged

(a)   magnification is applied during data acquisition, before storage in the scan converter

(a)   magnification is characterized by:

the image used to identify the ROI is discarded and all new image information is acquired.

The number of pixels or scan lines in the ROI images is greater than the original

Read magnification is considered (a)  

Write magnification is considered (a)  

Write magnification __ spatial resolution and may __ temporal resolution

(a)  

(a)   is a sophisticated method of improving image quality

Coded excitation occurs (a)   the epulser

Higher signal to noise ratio

Improved axial resolution

Improved spatial resolution

Improved contrast resolution

Deeper penetration

(a)  

(a)   is a method of using sonographic information from several different imaging angles to produce a single image

Without spatial compounding, (a)   appears in the image

(a)   is an advanced technique that reduces speckle artifact and noise in ultrasound images

• •Reflected signal is subdivided into bands of frequencies which are then combined.

(a)   is an image processing method that makes pictures look sharper

• •Emphasizes sharp edge boundaries

• •Increases image contrast around the edge

(a)   is an image processing technique that continues to display information from older images

Persistence or Temporal Avg

(a)  

• •Current frames are superimposed to old ones Smoother image, higher image-to-noise

Improves image quality, but reduces frame rate, which in turn reduces (a)  

(a)   a method of constructing new simulated data points to fill in the gaps. Increases line density (improves spatial resolution) and improves ability to precisely visualize the borders of round structures

Picture archiving and communications system

(a)  

Describes the digital ultrasound laboratory in which images and additional medical information are digitized and stored in the computer

(a)  

Digital imaging and computers in medicine

(a)  

A set of rules, or protocols, that allows imaging systems to share information on a network

(a)