Image production 31-32

Immediately before the advent of digital imaging systems, the most commonly used flim/screen combinations in radiography had a speed of

400

A digital speed class of 400 assumes an average exposure of _____ will reach image receptor

5 ugy

You may use a bar code from the CR cassette to _____________________ an image to a study.

Assign

Which part of the diagram flips image horizontally ( translation)

B

One main reason that the dynamic range of a digital image processing system must be much greater than the actual gray scale used in the image is to prevent data clipping when the image is windowed for _______ or ______

Brightness or Contrast

Which part of the diagram flips image vertically ( inversion)

C

For most CR systems, dragging the cursor vertically on the display screen can be used to adjust the _____ of the displayed image

Contrast

True saturation is a phenomenon that occurs at the _____ ____ _____

DR detector plate

A high window level will result in a

Dark Image on the displayed digital image

_____ _____ is generally recommended for all images being viewed.

Dark masking

How is the "speed" of a CR system determined

Department management + QC technologist

The _____ ____ is taken from data at the image receptor, ( not at the patient's surface or within the patient), the ____ _______ is a "guide to exposure intended to indicate the acceptability of signal-to-noise ration conditions

Deviation Index

The application of alternate algorithms is generally ______ it can be of value for some images, but changes are not always appreciable, and can even make the image worse

Discouraged

_______ _______ of the digital image should not be so extreme that the image becomes pixelly where individual pixels become apparent and sharpness of details is lost. It is controlled by display screen size, matrix size, and field of view.

Display Magnification

What error can cause the exposure indicator to be corrupted

Exposure Field Recognition

The _______ ____ is determined by the computer by finding the mid-point between Smin and Smax in the main lobe of the generated histogram for the image.

Exposure Indicator

Anything that can result in a histogram error can result in a

Exposure Indicator Error

An example of an area operation would be

Zoom (magnification)

If the dynamic range of a digital processing system is too limited, it is possible for ______ _______to occur when the displayed image is later windowed:

data clipping

Mottle is likely to appear in the computerized image any time the

exposure indicator is very Low

Inverting an image top-for-bottom would be a

global operation

To achieve exposure indicators within the correct recommended range, it is essential that ___ ___ and ____ _____ technique combinations be utilized for adequate penetration and low dose.

high kVp and low mAs

On most digital systems, image brightness can be increased by holding the mouse button down and moving the cursor to the ____

holding the mouse button down and moving the cursor to the right

Moving from film/screen imaging to digital imaging ___________ patient exposure.

increased

While a histogram graph plots the number of pixels against each pixel value, a frequency distribution plots the number of _______________ against their size.

objects

When the proceeing speed of the CR or DR system is doubled, the IR plates needs to only receive _____-____ as much exposure for the whole system to produce the proper image

one-half

What button send the image with its current settings into a file the PAC system

Accept Image/Deliver

Mottle in a CR or DR image can result from: A. Excessive kVp B. Excessive mAs C. improperly calibrated AEC

All of the above

Nearly all modern CR and DR systems can be operated at a speed class of _______ without the appearance of substantial mottle in the image. A. 300 B. 350 C. 400 D. All of the above

All of the above

The general types of scales used for exposure indicators are: A. Inversely proportional scales B. Logarithmic scales C. Proportional scales D. All of the above

All of the above

From the image review screen, usually by touching the histogram, an image re-processing screen can be accessed for: a.Applying alternate algorithms c.Adding annotations, markers, or arrows to the image b.Applying a black "mask" (border), reversing or making other changes to the image d.All of these

All of these

Using _______________________ _________________ methods preserves the original data set for an image while allowing modifications in its appearance on the display monitor to be made.

Alternate Algorithm

All of the following are general domains in which a digital image can be processed except

Amplitude

A deviation index of -3 indicated an under-exposure of __/___ the ideal level

1/2

For all manufacturers, the acceptable range of exposure indicator values is determined by the original x-ray exposure falling within ____/____ to _____ of the "ideal exposure level:

1/2 to double

Early CR readers (processors) were typically installed to operate at a speed of ________ which is the inherent speed of the photostimulable phosphor plate used as a CR image receptor.

200

Saturation

8

Maximum spatial frequency should be apparent in electronic images and at least ___LP/mm for static images and at least ___LP/mm for digital fluoroscopy.

8/6

Which part of the diagram restores all adjusted settings to original values

A

Ultimately, the acceptable ranges of exposures is decided by the __________ the imaging department. A. Management B. Staff radiographers C. Quality control technologist D. A&C E. All of the above.

A &C

Each manufacturer provides a target range of acceptable exposure indicator values, centered around the mean average, for guidance to radiographers as to whether an appropriate level of radiographic technique was used. T/F

False

Sorting an image by the size of the objects within it results in a

Frequency distribution

Noise in the image caused by electronic malfunctions is normally periodic, occurring at regular intervals across the image, (rather than random, such as quantum mottle). This periodic type of noise is best eliminated from a digital image using processing in the

Frequency domain

For each image in the PACS, the exposure indicator is to be permanently stored as part of the DICOM:

Header

What is used for scoliosis series, three CR plates can be exposed with a single exposure using a special wire mesh alignment grid.

Image Stitching

The weakest link in the radiographic imaging chain is usually the:

Image display system

The above image is a result of

Image reversal

The ____ ____ is used for windowing adjustments, presentation of histogram and exposure indicator.

Image review

What icon is usually preseted for "zooming" in or out of the image

Image review

What problem can the over-use of edge-enhancement features causes in a digital image?

Increased noise

The speed of a digital imaging system is ____ _____ to the amount of exposure required to produce adequate signal for processing:

Inversely related

A smaller "core" matrix of mathematical values which is passed through the entire image matrix, multiplying the value of each image pixel sequentially by the numbers in it, is called a

Kernel

What are set defaults procedure codes and generic setting for the equipment, only accessible to QC technologist or supervisors with a password.

Key Operator Functions

To evaluate the level of image mottle and other noise, it is helpful to use the

Magnification mode

Sorting an image by the location of its pixels results in a

Matrix

The standardized exposure indicator recommended by the AAPM in 2009 is based on actual exposure to the image detector measured in

Microgray

True saturation presents an area of the image with

No details at all present

The exposure indicator is ___ related to the brightness of the image displayed on the monitor screen

Not

When an alternate algorithm has been used to successfully improve an image, the best follow-up for PACS storage is to save both

Original and the copy as separate files

In any digital, the distance from the center of one pixel to the center of the next adjacent pixel is called the

Pixel pitch

The application of a single mathematical operation equally to each and every pixel in the image is a ______ _______ ________

Point processing operation

For the "black bone" processing feature, which inverts all brightness values within the image, the gradation curve is:

Reversed

Display magnification of a digital image is controlled by all of the following except: A. SID/OID ratio B. Display screen size C. Matrix size D. Field of view

SID/OID ratio

No overexposed digital image should ever be repeated, no matter the EI, unless ______ has occurred:

Saturation

What is extreme over-exposure can overwhelm the digital detection system, causing a loss of data that results in a flat black appearance of the over-exposed portion of the image.

Saturation

When approving CR images, why should the radiographer generally not save adjustments made to the brightness and contrast of a "sub-optimal" original image into the PACS?

Saving the changes into PACS permanently erases some image data

For a quality digital image, the highest possible ______-to-______ ratio should be archived

Signal to noise

What suppresses image noise ( mottle) with an attendant slight decrease in contrast throughout the image.

Smoothing

Every image begins and ends in the

Spatial domain

Point, area, and global operations are all subcategories within the

Spatial domain

nearly all modern CR and DR systems can be operated at a ______ _____ of 350 or 400 without the appearance of substantial mottle in the image

Speed Class

Contrast and Gray Scale should be balanced such that the number of details present in the image is maximized, and there is sufficient visual differentiation between adjacent details. T/F

T/F

Which of the following is it recommended to make a permanent record of for each image

The Exposure indicator

All pixel brightness levels within the anatomy of interest should be neither completely white nor pitch black, but should possess an intermediate shade of gray along a broad range from very light to very dark.. T/F

True

Although Right and Left markers are available electronically, errors are reduced by using physical markers, which are also strongly recommended for legal reasons. T/F

True

In 2009, the American Association of Physicists ( AAMP) recommended a standardized exposure indicator for use between all manufactures, that should be prominently displayed immediately after every exposure. T/F

True

The reject button on most systems results in permanent loss of the image, making "repeat" analysis hard to preform. When prompted to enter the reason for a reject, it is important to enter an honest answer rather than "other". Departments must find ways to make a reject analysis possible. T/F

True

There is no immediate, obvious feedback ( reinforcement) to the radiographer when excessive technique has been used for an exposure. T/F

True

_________ Is a more accurate term describing what dynamic range compression really does is gray scale

Truncation

Tissue equalization or dynamic range compression cannot improve _____ ______ portions of the image

Under penetrated

A histogram is the result when a digital image is sorted by the ______ contained by each pixel

Values