Introduction to Digital Radiography and PACS (real nani)

RT202

A: To provide a light-tight environment for safe film handling and chemical processing.

Q: What is the purpose of a darkroom in radiography?

A: Because light would expose and fog the film, ruining the image.

Q: Why can’t we process x-ray films in an ordinary room?

A: Light is produced, which interacts with the film to create a latent image.

Q: What happens when x-rays strike the intensifying screen in conventional radiography?

A: The invisible image on film before chemical processing.

Q: What is the latent image in conventional radiography?

A: The visible image formed after chemical processing (black metallic silver).

Q: What is the manifest image in conventional radiography?

A: Barium fluorohalide with europium activator.

Q: What material is used in most CR plates?

A: X-rays deposit energy inside the phosphor plate.

Q: How is the latent image stored in CR?

A: By scanning the plate with a laser in the CR reader.

Q: How is the CR latent image released?

A: A photomultiplier tube.

Q: What converts the light signal into an electrical signal in CR?

A: Through an analog-to-digital converter (ADC).

Q: How is the CR signal digitized?

A: CR uses a cassette with a phosphor plate, while DR uses a flat-panel detector without cassettes.

Q: What is the main difference between CR and DR?

A: Instantly on the computer.

Q: How fast are DR images available?

A: It requires advanced detectors, but saves money long-term by eliminating cassettes and readers.

Q: Why is DR more expensive?

A: Picture Archiving and Communication System.

Q: What does PACS stand for?

A: DICOM (Digital Imaging and Communications in Medicine).

Q: What format must images be in for PACS?

A: File room, reading room, duplicator, courier; provides multi-user access, on-demand images, and image processing.

Q: What are the functions of PACS?

A: VA Medical Center, Baltimore (1993).

Q: Where was the first full-scale PACS in the U.S. installed?

A: RIS (Radiology Information System), HIS (Hospital Information System), and EMR (Electronic Medical Record).

Q: What systems can PACS connect with?

A: Computed Tomography (CT).

Q: After x-rays, what was the next major milestone in medical imaging?

A: Godfrey Hounsfield; several hours to acquire and days to reconstruct.

Q: Who built the earliest CT unit, and how long did it take to reconstruct an image?

A: Paul Lauterbur.

Q: Who published the 1973 article that contributed to MRI development?

A: Early 1980s.

Q: When was MRI introduced commercially in healthcare?

A: Computer technology and analog-to-digital converters.

Q: What made fluoroscopy advances possible in the 1970s?

Dr. Albert Jutras, Canada, 1950s

He introduced the concept of moving images digitally in his experimentation with teleradiography

A: Film inside a cassette with intensifying screen.

Q: What is the image receptor in Conventional Radiography?

A: Photostimulable phosphor plate in a cassette.

Q: What is the image receptor in Computed Radiography?

A: Flat-panel detector (no cassette).

Q: What is the image receptor in Digital Radiography?

A: DR (instant images).

Q: Which is fastest: Conventional, CR, or DR?

A: Conventional Radiography.

Q: Which method still requires chemical processing?

A: Conventional Radiography (film + chemicals + storage).

Q: Which is considered the cheapest initially but costly long-term?

A: Digital Radiography.

Q: Which method is most advanced but expensive upfront?

Indirect Capture DR

• X-rays → converted into light → light converted into electrical signal → sent to computer.

• Uses devices like CCD (Charged Coupled Device) or TFT (Thin-Film Transistor)

Direct Capture DR

• X-rays → converted directly into an electrical signal (no light step).

• Uses a material called a photoconductor.

• More efficient and faster than indirect.

Head/brain

The first commercial CT scanners were designed only for the ________, not the whole body.

Photostimulable phosphor (used in CR)

PSP?