ch. 1 intro and PACS

(F/S) film is placed on 1 or between 2

intensifying screens

(F/S) screens emit light when struck by

x-rays

(F/S) light and x-rays expose film to create

latent image

(F/S) the film is processed

chemically

(F/S) on the film is viewed on a lightbox.

manifest image

Any image acquisition process that produces an electronic image

digital imaging

The term was first used in the 1970s with the development of

computed tomography (CT)

image can be viewed and manipulated on a

computer

developed the first CT scanner, bringing imaging devices and computers together.

Hounsfield

first commercial ct scanners imaged

the head only

MRI: article by __ led early pioneers

Paul Lauterbur in 1973

made digital capture possible

analog to digital converter

__ were easily converted to a digital image file

frame grabbed images (screen capture)

Moving images via telephone lines to and from remote locations

teleradiology

In the 1980s, U.S. government supported development of early PACS systems, specifically, for the

US military to send images

PSP previously known as

computed radiography

PSP equipment

PSP storage plate/reader

storage phosphor plate similar to intensifying screens and store

x-ray energy for an extended time

Uses an x-ray absorber material coupled to a TFT, CMOS, or CCD to form the image

flat panel detectors

2 types of FPD

indirect and direct capture

-Device absorbs x-rays and converts them to light.
-Light is collected by an area-CCD, CMOS, or TFT and is converted into electric signals.
-Electronic signal sent to ADC

indirect capture CR

-Photoconductor absorbs x-rays and converts them to electrical signals.
-TFT collects and sends the signal to the analog-to-digital converter (ADC).
-Computer turns digital data into an image.

direct capture CR

use a traditional x-ray room with existing table and wall Bucky assemblies

Conventional F/S and PSP

A detector replaces the table and wall Buckys.
• Or, portable detector is used in existing equipment

FPD

which imaging system has the best efficiency rating?

FPD

Conventional F/S x-rays strike intensifying screen, producing

light

Conventional F/S light and xray photons interact with __ in film emulsion

silver halide grains

Conventional F/S electron ejected and attracted to

sensitivity speck

Conventional F/S after chemical processing, sensitivity specks are processed into

black metallic silver (manifest image formed)

PSP made of

barium fluorohalide

PSP has __ activator

europium

PSP, some of photon energy is deposited within the phosphor particles, creating the

latent image

PSP plate is fed through

PSP reader

PSP ___ scans the plate, causing the electrons to return to their original state, emitting light in the process.

focused laser

This light is picked up by a __ and converted into an electrical signal.

photomultiplier tube

The electrical signal is then sent through an ___ to produce a
digital image that can then be sent to the technologist review
stat

ADC

are cassettes required for FPD?

no

PSP in that the x-ray energy stimulates a scintillator, which gives
off light that is detected and turned into an electrical signal

indirect capture

x-ray energy is detected by a photoconductor that converts it directly to
a digital electrical signal

direct capture

F/S Image is determined by the shape of the __and the processing chemicals

film’s response curve

F/S __ response of film

nonlinear characteristic

radiographic contrast is primarily controlled by

kVp

optical density is primarily controlled by

mAs

PSP and FPD responds in a

linear manner

PSP and FPD exposure latitude is

wide

PSP and FPD subject contrast is influenced by

kVp

PSP and FPD image noise is influenced by

mAs

an image processing algorithm, controls quality of image display.

Look Up Table (LUT)

which image capture system is most sensitive to scatter?

PSP and FPD

quantum mottle resulting from low mAs values is seen on

all 3 image capture systems

Networked group of computers, servers, and archives used to manage and store digital images

PACS

PACS can accept any image that is in

DICOM format

first full scale PACS

VA in baltimore 1993

Components of pacs can vary based on

volume of patients

number of interpretation areas

viewing locations

funding

components of PACS

reading stations

work stations

archive system

With all acquisition systems, every image capture still begins by placing the

pt between xray source and receptor

t/f lower technical factors should not compromise image quality

true

is the medium for capture, display, and storage

film

there is no physical record of the digital image unless it is

printed to film

__ is no longer a factor of image formatting

cost of film

__ on digital receptors can compromise image processing

multiple exposures

Patient identification is more important with digital imaging because

incorrect or incomplete data may make retrieval impossible.

Postprocessing labels should annotate

pt position and timing

patient dose changes with

speed

slow scans equal

more patient dose

PSP can use __ to reduce patient dose but maintain image quality

higher kVp, lower mAs (using 15% rule)

which image capture could capture more than one projection on image?

F/S

which image capture has all information attached to files?

digital