Chapter 1: Intro to Digital Radiography & PACS (Test 1)

Conventional/Film Screen Radiography

What type of radiography method has a film-based image formation process?

Intensifying screens

What does conventional film/screen radiography use to capture the image?

Between two intensifying screens

In conventional film/screen radiography, where is the film placed?

Intensifying screens emit light

During conventional film/screen radiography, what happens to the intensifying screen when X-rays strike it?

Chemically and on a lightbox

How is film processed and viewed during conventional film/screen radiography?

- Film too light/dark = repeat

- Film can't show differences in tissue contrast less than 10%

- Limited contrast resolution

- Archiving

What are some limitations of film/screen radiography?

Spatial resolution

What is the main advantage of film/screen radiography?

- 10-15 lp/mm

- 2.5-5 lp/mm

- 2.5-10 lp/mm

- What is the spatial resolution of film/screen?

- What is the spatial resolution of CR?

- What is the spatial resolution of DR?

Contrast resolution

What is the main advantage of digital imaging?

Because of post processing modes

Why is the contrast resolution the main advantage of digital imaging?

- Great latitude systems

- Less patient exposure

- Fewer repeats

What are some other advantages of digital imaging?

Digital Imaging

What refers to any imaging acquisition process that produces an electronic image that can be viewed and manipulated on a computer?

Images that can be sent through a computer network to many locations

What can most medical imaging modalities produce?

1970s; CT

When was the term digital imaging first used, along with the development of what?

Teleradiology (Nighthawking)

What refers to the practice of a radiologist interpreting medical images while not physically present in the location where the images are generated?

- Scanning

- Sampling

- Quantization

What are the three steps of digital imaging production?

Scanning

What step of digital imaging production is where the matrix (rows and columns) is formatted and the field of the image is divided into an array of small cells?

Sampling

What step of digital imaging production refers to the intensity of light or radiation from each pixel that is measured by a detector?

Quantization

What step of digital imaging production refers to a value assigned to each pixel's intensity?

A discrete gray level (a number)

What does the quantization value represent?

Decimal System

What operates on a base of 10 different numbers (0,1,2,3,4,5,6,7,8,9) and is used by humans?

- Binary System

- 0 (off) and 1 (on)

- What number system do computers use that operates on the base of 2?

- What are these numbers?

Binary digits or bits

What are the numbers in the binary system called?

- Photostimulable Phosphor (PSP)

- Plate Reader

What are the CR components of digital imaging?

Flat Panel Detector Systems

Which radiographic image capture method uses an X-ray absorber material coupled to a thin-film transistor (TFT), complementary metal oxide semiconductor (CMOS), or a charge-coupled device (CCD) to form the digital radiographic image?

- Indirect Capture

- Direct Capture

What are the two image-capturing methods used with DR flat panel detectors?

- X-rays converted to light ➜ Light converted to electrical signal

- X-rays converted to electrical signal

- When using flat panel detectors, what is the indirect capture process?

- When using flat panel detectors, what is the direct capture process?

- Light production

- Indirect capture

- Direct capture

- What is scintillation?

- What image-capturing method is scintillator-based?

- What image-capturing method is not scintillator-based?

- Radiographic contrast

- Optical density

- In film/screen radiography, what does kVp control?

- In film/screen radiography, what does mAs control?

- Subject contrast

- Image noise

- Radiographic contrast and density

- In digital imaging (PSP and FPD), what is influenced by kVp?

- In digital imaging (PSP and FPD), what is influenced by mAs?

- In digital imaging, what is primarily controlled by an imaging processing algorithm and a look-up table (LUT)?

Scatter

In comparison to film/screen, what is digital imaging more sensitive to?

Quantum Mottle (Noise)

What results from low mAs values that can be seen on film/screen, photostimulable phosphor, and flat panel detectors?

Picture Archival and Communication Systems (PACS)

What refers to a networked group of computers, servers, and archives used to manage and store digital images that also provides image access to multiple users at the same time, on-demand images, electronic annotations of images, and specialty image processing?

Digital Imaging and Communications in Medicine (DICOM) format

PACS can accept any image in what kind of format?

Hospital Information System (HIS)

What is a comprehensive digital system that manages various administrative, financial, and clinical operations within a hospital and acts as a central hub for patient information, treatment plans, and billing?

Radiology Information System (RIS)

What system holds all radiology-specific patient data from patient scheduling information to the radiologist's report?

PACS

What holds images for all modalities?

- Patient name

- Health care facility

- Patient ID number

- DOB

- Examination date

- Exam data (postural and side markers)

What are the 5 patient demographics that have to be on radiographic images?

- During pt. registration

- Linked by barcode

- Manually entered

How is patient demographic information entered?

Lead side markers (R and L)

What should be used for all radiographic images legally?

- All documents are scanned and all important info is documented

- All annotations necessary are included on images

- Annotations may not be changed once sent

When preparing a radiographic image for reading, what do you need to ensure?