Digital Imaging receptors

Digital image receptor responds to a ___ ___ of exposure values to create diagnostic images.

Wide Range

The term ___-___ describes the process of creating a digital image using a cassette.

Cassette-based

The term ___-___ describes the process of creating an image when a technologist does not touch a cassette.

Cassette-less

Photostimulable phosphor stores the ___ from its interaction with an x-ray beam.

energy

In a cassette-based system, the cassette holds the ___ plate.

PSP (photostimulable phosphor)

Flat-panel detectors come in two variables which are:

Scintillator and non-scintillator based.

A scintillator-based flat-panel detector converts the X-ray beam into ___ to create an image.

electrons

The CCD image receptor uses a ___, so it needs a material that gives off light when the x-ray beam strikes it.

Scintillator

The digital image is a ___ of numbers, known at pixels, that corresponds to the intensity of the x-ray beam that strikes a particular area.

Matrix

Brightness in digital imaging is equivalent to ___ in an analog image.

Density

If a technologist says, : “that is a insufficient density. But in digital world, the image is too ___.”

Bright.

Image blur is a result of ___ during an exam.

Motion

Each vendor provides a set of numbers known as ____ ____ that confirm that a coreect exposure is used in producing a digital image.

Exposure indicators.

Image noise is the ___ appearance on an image.

Grainy

The main difference in evaluating analog and digtal images involves ___ an ___.

Brightness and Contrast.

What primarily determines what an image looks like in digital imaging?

The computer

Phosphor converts X-ray photons into ___.

For analog image receptors, we referred to them in terms of ___ ___.

light ; relative speed

The two phosphor types available for photostimulable phosphors are called:

Turbid, Needle or Columnar

When an X-ray photon energy strikes the phosphor crystals, causing electrons in the crystals to move from their normal orbit location to a higher energy, what does this action form?

Latent image in the receptor.

A laser light source scans the ___ ___ to ectract the image

Receptor plate

The laser light exposure then causes electrons at high energy states (those that form the latent image) to release their energy as ___ and return to a lower energy resting state.

light

The light released from the ___ following laser scanning is collected and used to record the patients image.

PSP (photostimulable)

The two types of flat-panel image receptors available are:

Scintillator based and non- scintillator based.

Scintillators and non-scintillators use:

Cesium iodine or gadolinium oxysulfide.

The cesium iodine comes in a ___ ___ formation.

Columnar needle.

The gadolinium oxysulfide comes in a ___ formation.

Turbid

A scintillator converts X-ray photons into ___, which are emitted to interact with a photoconductive material typically made of amorphous silicon. The electrons created in the silicon then migrate to to thin film transistors and produce ___ signal.

Light ; electric.

The non- scintillator flat- panel receptor ___ ___use material that converts x-ray beam into light. Instead, non-scintillator image receptors use amorphous selenium to convert the X-ray beam to ___ that thin film transistors can collect.

Does not ; electrons

The thin film transistor is a complex circuit device that collects ___ emitted from either amorphous selenium or amorphous silicon.

Electrons

DELs collects the ___ that represent individual components of a digital image.

Electrons

Charge-coupled devices (CCDs) need a ____ to produce light.

Scintillator

CCDs are considered an ___ form of image capture.

Indirect

Higher Spatial frequencies represent ___ number of viewable objects in an image.

Larger

Pixel size is the characteristic we look at first when considering digital image ___ ___.

Spatial resolution

Pixel size is measured from ___ to ___ within an individual pixel.

Side to side

Pixel pitch is measured from ___ of one pixel to the ___ of an adjacent pixel.

Center ; center

The size of the ____ ____, or DEL, determines the spatial resolution of a flat panel detector element.

detector element

The ___ frequency determines the level of spatial resolution for an image receptor.

Nyquist

The term ___ ___ refers to an image receptor’s ability to respond to different exposure levels.

Dynamic range

For technologists, what is the only visual cue that indicates when the digital receptor is underexposed?

Quantum noise

When an image is slightly to greatly overexposed, the image contrast is ___.

Decreased

With receptor blur, the cause is in the :

Equipment

A large focal spot produces ___ image blur than a small focal spot.

Greater

Increasing SID ____ the blur in an image.

Decreases

Technologists always want to minimize the OID distance to reduce ___.

Blur.

When a single X-ray strikes the input phosphor of an image intensifier to produce light photons that immediately are converted into electrons by the ___.

Photocathode.

PSP is only :

Cassette- based

flat panel detectors and CCDs are :

Cassette- less

CCDs primary application:

Flouroscopy