ch 17 & 18 digital imaging Mclaughlin

This photometric quantity & eye response allows you to see bright light/daylight.

Cones

This photometric quantity & eye response allows you to see dim lights/ night vision

Rods

_____ is the basic unit of photometry

Lumen

The intensity of light from a source is referred to as _____

Luminous flux

The intensity of light incident on a surface is referred to as _____.

Illuminance

When luminous flux is emitted into an entire viewing area it is called____.

Luminance intensity

______ is similar to luminance intensity.

Luminance

Luminous intensity _____ in proportion to the inverse Sq. LAW.

Decreases

When viewed from an angle ____& ___ are reduced

Contrast & luminous intensity

When a monitor is viewed straight on the luminous intensity is greatest @ 90*

Cosine Law

An example of hard copy viewing is ___.

Film on a view box

Digital images read from a monitor, LCD, or LED are called_____

Soft copy

_____ has properties of a solid crystal & fluid.

Liquid Crystal Display

Liquid crystals are ____\ forming a natural molecular dipole (+-)

Electrically charged

Liquid crystals can be aligned by an _________ & open or close

Electrical field

Color LCDs have ___, ____,____ built in filters in each pixel.

Red, Green, Blue

Medical LCDs are _____ devices

Monochrome

A ____ is fluorescent or LED & illuminates all pixels. It is blocked when transmitted by the orientation of the liquid crystals.

Backlight.

____ % of backlight is transmitted through a monochrome monitor.

10%

Some light is absorbed in filters and polarizers blocked by the ____& _____.

TFT & Bus lines

T/F, LCD monitors have the ability to control ea. pixel individually.

True

Which has better grayscale definition & contrast resolution?

A) LCD B) CRT

LCD

LCDs have NO____, ____ & less ____.

Glare, Reflection & les noise

This occurs when photons falling on one pixels are “Falsely” sensed by other pixels around it.

Crosstalk

T/F, Led allows current to flow in multiple directions?

F, only one direction.

LED are thicker or thinner?

Thinner

T/F, LED provides the backlight for LCD displays.

True

LEDs have a ____ active area for the visual screen.

Larger

LEDs have ______life than fluorescent lights.

Longer

AMLCD =

Active Matrix LCD

_____ reduces the effect of ambient light in image contrast

AMLCDs

How should ambient light levels be?

Near dark

Ergonomic design of the reading room ensures ______ viewing

Perpendicular

______ automatically manipulates the image before display.

Preprocessing

T/F , preprocessing is designed to produce artifact- free images

True

_____ images & ____ images make the response of the image receptor uniform. This is known as _____

Offset & gain, flatfielding

When a dead or defective pixel’s value is averaged from surrounding pixels it is called_____.

Signal interpolation

Anything done to the digital image after it is acquired is known as_____

Post processing

TF. Post processing can optimize the appearance of an image to better detect pathology?

True

____is when you add text

Annotation

Window & level control___& ____

Contrast & brightness

Image inversion does what?

Makes an image black to white & white to black

DSA (subtraction removes any unwanted info. T/F

True

ROI- _______ measures the ______of pathology.

Quantitative Radiology

Density

_______ is used for small fractures & small high contrast tissues

Edge enhancement

Highlighting is used for ____, non focal disease

Diffuse

___,___,___ are used to see precise regions of an image

Pan, scroll, zoom

List the 4 principal components of PACS

(IDNS)

Image Acquisition System

Display system

Network

Storage

The _____ connects each client (imaging system & workstation) to a central computer.

Network

Teleradiology is the ____ transmission & ____ of images

Remote & viewing

_____ ensures adaptability between different imaging systems. It is the national standard for image transmission in teleradiology.

DICOM

Digital imaging & Communications in Medicine

DICOM files contain____that provide info about image such as :___,___,___,___ & is used to create the data & equipment settings used to capture the image.

Metadata

Size, dimensions, bit depth, modality

_____ is the database system for radiology departments, it restores imaging pt info, reports accounting, etc…

radiology information systems

RIS

_____archives pt. Images

PACS

List the devices/ clients that are interconnected in a radiology network.

Imaging systems, hospital mainframe, workstations, radiologist computer, web server, web clients

What prevents lost images?

PACS

EMR

Electronic medical record

HIS & RIS hold/ Store _____

EMRs