The ABR CORE physics domain spans X-ray production, CT imaging principles, MRI physics, ultrasound, and nuclear medicine. It requires conceptual understanding and application of principles to clinical scenarios. A structured practice routine can help turn the blueprint topics into an organized study plan.
This guide summarizes blueprint-aligned topics, practical study pitfalls, and ways to use practice questions alongside authoritative references.
What Physics Covers on the ABR CORE Exam
The ABR physics domain is the broadest of the three non-interpretive sections, covering five imaging modalities and their underlying physical principles. The content is organized around modality-specific physics concepts and cross-cutting principles.
**X-ray and Fluoroscopy Physics** covers the fundamentals of X-ray production, the X-ray tube components (cathode, anode, filament), heel effect, grid function and grid ratio, image receptor technology, and fluoroscopic dose management. Questions often test your understanding of how changes to technical parameters (kVp, mAs, SID) affect image quality and patient dose.
**CT Physics** is an important study area. Generations of CT scanners, reconstruction algorithms (filtered back projection, iterative reconstruction), CT number (Hounsfield unit) definitions, spiral/helical CT principles, pitch calculation, noise sources, and CT dose descriptors (CTDI, DLP) are all useful topics to review against the current blueprint.
**MRI Physics** covers the Larmor frequency, relaxation times (T1, T2, T2*), pulse sequences (spin echo, gradient echo, inversion recovery, STIR, FLAIR), k-space and Fourier transform relationships, parallel imaging techniques (GRAPPA, SENSE), and MRI artifacts and their causes. The relationship between sequence parameters and image contrast is a classic question type.
**Ultrasound Physics** includes piezoelectric effect, transducer design, pulse-echo principle, ultrasound artifacts (shadowing, enhancement, side lobe), Doppler principles, spatial and contrast resolution, and ultrasound safety (ALARA in ultrasound, mechanical index, thermal index).
**Nuclear Medicine Physics** covers radioactive decay, radionuclide properties, gamma cameras, SPECT and PET acquisition principles, attenuation correction, image quality factors, and radiation dosimetry for radiopharmaceuticals.
Physics Concepts to Include in Your Review
Use the current ABR blueprint to build coverage across modalities. The following are practical study topics, not a ranking of exam frequency or outcome impact.
Practical Physics Study Pitfalls
Several study choices can make physics review less useful:
**Treating physics as a reading subject.** Physics is a doing subject. Reading a chapter on CT reconstruction algorithms without working through questions afterward produces almost no durable learning. The concepts have to be actively applied to become accessible under exam conditions.
**Studying each modality in isolation without connecting principles.** Many physics concepts apply across modalities — spatial resolution, noise, artifact formation, dose. Residents who study modalities in isolation miss these connections and have to memorize more than necessary. Studying cross-cutting principles explicitly reduces the total cognitive load.
**Memorizing formulas without understanding their meaning.** The CORE exam rarely asks you to plug numbers into a formula. It asks you to reason about what happens when a variable changes. Residents who memorized pitch calculation without understanding what pitch means struggle when questions present clinical scenarios.
**Skipping nuclear medicine physics.** Nuclear medicine is the most commonly skipped physics topic, which means it's also the most likely to surprise residents on exam day. The physics is not as complex as MRI — the fundamentals are learnable in a focused study period.
**Not using practice questions early enough.** Physics questions reveal which conceptual frameworks you've actually internalized versus which ones you just read once. Starting with questions rather than ending with them is a more efficient study sequence.
How Physics Practice Questions Build Exam Fluency
Working through radiology physics practice questions does more than test recall — it builds the cognitive fluency needed to apply principles quickly under exam conditions.
**Scenario-based questions train clinical reasoning.** Well-written physics questions don't ask "what is the Larmor frequency?" They present a clinical scenario: "A patient is imaged at 1.5T and then at 3T. How does this affect the RF pulse frequency required for excitation?" This format trains you to apply physics principles to the situations you'll actually encounter.
**Incorrect answer explanations teach as much as correct ones.** The best physics questions include explanations for why each distractor is wrong, not just why the correct answer is right. This prevents the common mistake of selecting a plausible-sounding wrong answer because you vaguely remember reading something similar.
**Category analytics identify knowledge boundaries.** Your intuition about which physics topics you understand is often unreliable. Performance data by subcategory gives you an objective view of where your preparation is strongest and where additional work is needed.
**Spaced repetition through retesting solidifies retention.** Physics concepts studied once and not revisited are lost quickly. Using practice questions for spaced repetition — returning to previously missed questions days or weeks later — converts short-term learning into durable exam-day knowledge.
RadCore Physics: 580+ Questions Across All Imaging Modalities
RadCore's physics module is the most comprehensive section of the question bank, with 580+ practice questions covering all five imaging modalities. Every physics question is written by radiologists with ABR CORE exam experience and reviewed for accuracy against current physics references.
Questions are categorized by imaging modality and physics concept, and your performance analytics break down your accuracy accordingly. If your CT physics is strong but your MRI physics needs work, you'll see that in your dashboard — and you can build a targeted MRI physics custom set to focus your remaining study time.
Every question comes with a detailed explanation that teaches the underlying principle, not just confirms the correct answer. Explanations include the reasoning behind each distractor, ensuring that missed questions produce genuine learning rather than just score feedback.
Physics questions are updated regularly as the ABR updates the CORE exam content blueprint, ensuring you're never studying outdated material.