Module 1 - Lecture - Patient Dose and IQ

Flashcards covering patient dose, kVp, mAs, SID, and collimation concepts from the lecture notes.

The patient dose represents the energy absorbed and retained in the patient, measured in __.

Gray (Gy) [J/kg].

Which tissues absorb more radiation?

High atomic number and high-density tissues (e.g., bone, contrast media).

What does kVp control?

The beam’s quality (energy) and quantity (intensity).

Low kVp produces what kind of contrast?

High contrast (black and white, short-scale).

High kVp produces what kind of contrast?

Low contrast (many grays, long-scale).

What interaction dominates at low kVp?

Photoelectric Effect (PE).

What interaction dominates as kVp increases?

Compton Scatter.

What does mAs control?

The total number of X-ray photons produced.

Increasing mAs has what effect on patient dose?

Increases dose proportionally.

How does mAs affect contrast?

No effect (contrast depends on kVp).

How does mAs affect noise?

Decreases noise by improving signal-to-noise ratio.

What happens to beam intensity when SID increases?

It decreases (inverse square law).

How does a larger SID affect magnification?

Reduces magnification, improving detail.

What formula is used to adjust mAs for a change in SID?

New mAs / Old mAs = (New SID / Old SID)^2.

How does tighter collimation affect patient dose?

Decreases it (less volume irradiated).

How does collimation affect scatter?

Reduces scatter, improving image quality.

What is the effect of collimation on contrast?

Increases contrast by reducing scatter fog.