Chapter 6 RADR 1313

What does digital image processing refer to?

Computer manipulations applied to digital data.

What stage of digital image processing prepares raw data for processing and display?

Pre-processing.

Because of the electronic components of a DR image receptor, what can imperfections lead to?

Artifacts and malfunctioning pixels.

What is the histogram a graphic representation of?

The range and incidence of pixel values.

What does the location of the histogram along the x-axis represent?

Image brightness levels.

What does the shape of the histogram represent?

Image contrast.

What does the y-axis of the histogram graph represent?

Incidence (frequency) of pixel values.

What factors affect the location and shape of the histogram?

Collimation and positioning, kilovoltage and mAs values, and the anatomic area of exposure.

What is the process that uses computer algorithms to compare data with stored reference histograms?

Histogram analysis.

What determines the range of histogram data that should be included in the displayed image?

Values of interest (VOIs).

What numerical value indicates the level of radiation exposure to the digital image receptor?

Exposure indicator (EI).

What principally determines the final appearance of an image in terms of brightness and contrast?

Lookup table (LUT) application.

What computer process corrects overexposed radiographic images for excessive exposure?

Automatic rescaling.

What value reflects the difference between the desired target exposure and the actual exposure to the image receptor?

Deviation index (DI).

Which deviation index (DI) value indicates excessive exposure?

+3.

What do underexposed radiographic images typically demonstrate?

Quantum noise.

Based on histogram analysis, how is consistent image brightness accomplished?

Automatic rescaling.

What provides a method of altering the brightness and grayscale of a digital image?

Lookup table (LUT)

How do LUTs improve the quality of a displayed image?

They alter the pixel values of the exposure histogram to match the reference histogram.

What post-processing technique reduces the visibility of image noise?

Smoothing.

What post-processing technique improves the visibility of small, high-contrast structures?

Edge enhancement.

What does an image data set that has undergone equalization demonstrate?

Lower contrast but improved visibility of dense and lucent anatomy.

What removes the distracting area of increased brightness surrounding the radiation-exposed field from a displayed digital image?

Electronic masking.

What happens when the window level of a displayed image is changed?

Image brightness changes.

What happens when window width is increased?

Image contrast decreases.

What are important features of a display monitor used for diagnostic interpretation?

Matrix size, pixel size and pitch, and display dimensions.

What resolution display monitor should be used for diagnostic interpretation?

A high-resolution 5-megapixel display monitor.

What is luminance?

A measurement of the light intensity (brightness) emitted from the surface of a display monitor.

What is health informatics?

Data management for radiology services both within and outside the healthcare system.

What standards protect the privacy and confidentiality of patients’ information?

The Health Insurance Portability and Accountability Act (HIPAA).

What computer system receives, distributes, stores, archives, and displays digital images?

MIMPS (Medical Image Management and Processing System).

What is the communication standard for medical information?

HL7.

What is the communication standard for information sharing between MIMPS and imaging modalities?

DICOM.

What features should a display workstation used for image interpretation have?

Panning, annotation, and windowing.

What is the DICOM Grayscale Standard Display Function (GSDF) used to evaluate?

The display monitor.

What are components of protected health information (PHI) security?

Authorization, authentication, and anonymization.

What information should be included in the DICOM header of digital images?

Identification number, accession number, and total number of study images.

What creates an organized strategy for maintaining vital patient information and healthcare functions during EMR system disruptions?

Downtime procedure.

What do Exposure Index (EI) values measure?

Radiation exposure to the image receptor.

What may happen if an incorrect LUT is selected for an imaging study?

The displayed brightness and contrast will not look as expected.

What interpretive tool has digital image data enabled radiologists to use?

Artificial intelligence (AI).

How are challenges involving storage technologies from different manufacturers being addressed as healthcare systems expand and consolidate?

Vendor-neutral archives (VNAs).

What process is routinely used to improve the transmission and storage of large medical image data sets?

Image compression.

What allows diagnostic medical image interpretation outside the acquiring medical imaging facility?

Teleradiology

True or false: Once data are in digital format, image processing and display do not differ between CR and DR. .

True

True or false: Radiographers should routinely use alternative algorithms before sending images for diagnostic interpretation because image quality is always improved.

False

True or false: Overuse of digital image post-processing can negatively alter the data set and reduce its diagnostic and archival quality.

True

True or false: Proper collimation before radiation exposure is important and should not be replaced with electronic masking.

True

True or false: Health informatics is also known as radiology informatics within radiology departments.

True

True or false: Health information that can be linked to an individual must be secured and protected.

True

True or false: Reversible image compression results in some loss of image data at the end user.

False

True or false: Teleradiology is not recommended because of ineffective communication between teleradiologists and on-site imaging professionals.

False

True or false: Personal information collected from a patient to assist in their care is stored in the radiology information system (RIS).

False

True or false: The electronic health record (EHR) allows patient PHI to be shared outside a healthcare facility and among many systems.

True

True or false: Vendor-neutral archives (VNAs) require duplicate files to be placed in a remote location for recovery if primary files are lost.

False

True or false: Transmission devices must handle image volume within a reasonable timeframe and be able to check for errors.

True