Image Production and Evaluation Lecture Flashcards

Flashcards covering a range of topics from darkroom procedures, film and screen technology, processing chemistry, and radiographic quality control based on the lecture transcript.

According to OSHA, why are RTs (Radiologic Technologists) required to wear face masks in the darkroom?

The fumes in the darkroom are carcinogenic.

What is the definition of 'Latensification'?

An increase in sensitivity after exposure to white light or ionizing radiation.

What are the required physical barriers for a darkroom adjacent to an exposure room to protect against radiation?

Concrete greater than $6\,\text{inches}$, hollow blocks filled with cement, or wood with $1.5\,\text{mm}\text{ Pb}$.

What is the recommended range for air changes in a darkroom ventilation system?

$8-10$ changes per hour.

What is the new recommended temperature and humidity for a darkroom environment?

Temperature: $18-24\,^{\circ}\text{C}$ ($65-85\,^{\circ}\text{F}$); Humidity: $30-60\%$. Balance and moisture are measured using a Psychrometer or Hygrometer.

What are the specific purposes of white light illumination in a darkroom?

Maintenance, emergency cases, and cleaning.

Which safelight filter is brownish in appearance and used for monochromatic (blue-sensitive) film?

Amber Filter.

Which multi-purpose red-colored safelight filter is used for orthochromatic (blue/green sensitive) film?

GBX 2 Filter.

What is the primary disadvantage of panchromatic film?

No safelight can be used because it is sensitive to all visible light spectrum.

What is the acceptable Optical Density (OD) for a safelight fog test?

$0.04\,\text{OD}$. Results greater than $0.05\,\text{OD}$ indicate a failure.

How is the replenishment rate range defined in quality control for an automatic processor?

Within $\pm 5\%$, typically measured weekly.

What are the normal pH ranges for Developer and Fixer solutions?

Developer: $10-11.5$ (or $9.6-10.6$); Fixer: $4-4.5$ (or $4.2-4.9$).

What is the function of Phenidone and Hydroquinone in film sensitometry?

Phenidone is a film speed indicator and rapid reducer (controls the Toe); Hydroquinone is a film contrast indicator (controls the Shoulder).

What are the dimensions for a standard 90-second automatic processor temperature?

$33.8-35\,^{\circ}\text{C}$ ($90-95\,^{\circ}\text{F}$).

What was the significance of the year 1895 in radiographic history?

The use of photographic plates.

What is the primary advantage of Intensifying Screens regarding radiation dose?

They allow for $15-20\,\text{times}$ less radiation by converting x-ray energy to light.

What causes the 'Parallax Effect' (crossover) in duplitized film?

The apparent displacement of an image or light crossing through the base to expose the opposite emulsion, causing blur.

Which screen phosphor produces Blue, Indigo, and Violet line emissions but is not specific?

Calcium Tungstate ($CaWO_4$).

What are the three categories of Patient Treatment for breast cancer defined in the notes?

Surgery (mastectomy), Radiation Therapy (regional), and Chemotherapy (metastases).

What are the standard widths for Cine/Roll film used in cardiac catheterization?

$16\,\text{mm}$ and $35\,\text{mm}$.

How should film be stored to prevent pressure artifacts and sticking?

Vertical/Edge/Straight/Upright storage.

What refers to the 'First In First Out' (FIFO) rule in film handling?

Adhering to expiration dates to ensure the oldest film is used first.

What are the basic parts of radiographic film?

Topcoat (protective gelatin), Emulsion (the heart/active layer), Adhesive layer, and Base (foundation).

What is the composition and ratio of Silver Halide Crystals in the emulsion?

Silver Bromide ($35\,Z$) at $90-99\%$ and Silver Iodide ($53\,Z$) at $1-10\%$. Silver has an atomic number of $47\,Z$.

What theory is the only accepted explanation for the photographic effect occurring in the lattice of the emulsion layer?

Gurney-Mott Theory.

What are the primary reducing agents in automatic developer solution?

Phenidone and Hydroquinone.

What is the purpose of Glutaraldehyde in automatic processing?

It acts as a hardener (Tanning Agent) to prevent excessive swelling of the emulsion and protect against transport damage.

What is 'Hyporetention' (Thiosulfate retention)?

Inadequate washing that leaves silver sulfide stains, appearing as a pale yellow or brown color.

In the automatic processor transport system, what is the role of the Crossover Roller?

It moves the film from one tank to another (e.g., from fixer to developer).

What are the three most common methods of Silver Recovery?

Precipitation, Metallic Replacement (displacement), and Electrolytic Recovery (most common).

What is the '15% Rule' for kVp and density?

Increasing kVp by $15\%$ increases density by $15\%$ (equivalent to doubling mAs), while decreasing kVp by $15\%$ decreases density.

What is the difference between umbra and penumbra in radiographic definition?

Umbra is the true image; Penumbra is the geometric unsharpness or blurred area around the umbra.

Which factor most contributes to the production of scattered radiation within the patient?

Compton interaction, influenced by kVp, Field Size, and Patient Thickness.

What is the formula for Grid Ratio?

$\text{Grid Ratio} = \frac{h}{D}$ where $h$ is the height of lead strips and $D$ is the distance between them.

What is 'Grid Cutoff'?

The undesirable absorption of primary x-rays by the grid due to improper positioning (e.g., off-level, off-center, or upside-down).

Who invented the moving grid (Potter-Bucky diaphragm) in 1920?

Hollis E. Potter.

What are the advantages and disadvantages of the Air-Gap Technique?

Advantages: Reduces scatter radiation and enhances contrast. Disadvantages: Increases image magnification and focal-spot blur.