Physics · Subtopic

X-ray & Fluoroscopy

Tube design, beam production, interactions (photoelectric vs Compton), technique factors (kVp, mAs, SID), grids, fluoroscopy, and dose. The foundational subtopic: every other imaging domain builds on these primitives.

Categories Click to drill a 3-Q set

Production →Tube design, bremsstrahlung vs characteristic, K-edges, anode heel. Interactions →Photoelectric (Z³/E³), Compton, Rayleigh, pair production thresholds. Technique →kVp, mAs, the 15% rule, SID and inverse-square, AEC. Grids →Ratio, Bucky factor, cutoff patterns, alignment. Fluoroscopy →Pulsed vs continuous, II vs flat panel, DSA, mag modes. Dose →KAP/DAP, peak skin dose, RAK, deterministic vs stochastic. Digital detectors →CR vs DR, DQE, pixel pitch, dynamic range.

Study loops Pick one

MCQ Bank (20)

ABR-style questions with rationale, distractor explanations, and Radiopaedia links for every answer.

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Flashcards (20)

High-yield facts: 15% rule, K-edges, heel effect, DQE, KAP interpretation.

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Cases (3)

Grid cutoff, pediatric overexposure, and deterministic skin injury after prolonged TIPS.

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Domain Mock

Mixed physics-only timed mock. X-ray shares the pool with CT, US, MRI, and dose.

Microsims Interactive teaching tools

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kVp / mAs Explorer

Drag sliders; watch exposure, skin dose, and subject contrast move. The 15% rule becomes visceral.

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Inverse-Square Law

Change SID; see photon fluence fall as 1/d² and the required mAs compensation in real time.

Curated reading Go deeper

X-ray tube — Radiopaedia
Photoelectric effect — Radiopaedia
Compton scattering — Radiopaedia
Anti-scatter grid — Radiopaedia
Digital subtraction angiography — Radiopaedia
Dose-area product (KAP/DAP) — Radiopaedia
Bushberg — The Essential Physics of Medical Imaging, Chapters 6–11
Huda — Review of Radiologic Physics, Chapters 1–5