ABMP MRI for Radiation Therapy study guide
ABMP MRI for Radiation Therapy · Work through your exam, one topic at a time.
The ABMP MRI for Radiation Therapy credential is a professional certification for medical physicists who use magnetic resonance imaging in the radiotherapy workflow - from simulation and treatment planning through image guidance and verification. It signals that a physicist can operate MRI safely, understand image quality and artifacts, integrate MR data into planning and registration pipelines, and reason about how magnetic field and gradient effects interact with radiation delivery. The ABMP MRI for Radiation Therapy study guide has 8 sections and about 2,099 words.
01MRI Physics and Instrumentation
Candidates must be fluent in the proton as the MR signal source: net magnetization, precession at the Larmor frequency (ω = γB₀, with γ/2π ≈ 42.58 MHz/T for hydrogen), excitation by an RF pulse, and relaxation via T1 (longitudinal recovery) and T2/T2 (transverse decay). Know the spin-echo and gradient-echo sequences, TR/TE effects on contrast, and how flip angle and echo time drive gradient-echo weighting.
310 words, about 2 min02MRI Safety and Patient Management
Know the four ACR zones (I unrestricted, II transition, III restricted, IV magnet room) and who may enter each. Zone IV access requires MR personnel screening.
273 words, about 1 min03Image Quality, Artifacts, and Quality Assurance
Understand SNR, CNR, spatial resolution (voxel size, FOV/matrix), and how they trade off. Smaller voxels raise resolution but lower SNR; averaging raises SNR at time cost.
268 words, about 1 min04MR Simulation for Radiation Therapy
MR simulation provides superior soft-tissue contrast for target and OAR delineation, especially brain, prostate, head/neck, and pelvis. Understand the workflow: patient setup in treatment position, immobilization compatible with MR (non-ferromagnetic masks/cradles), indexing to the couch, and acquisition of planning-grade images.
247 words, about 1 min05Multimodality Image Registration and Fusion
Understand rigid vs deformable registration. Rigid (translation + rotation, sometimes scale) preserves distances; deformable allows local warping.
249 words, about 1 min06Treatment Planning Considerations with MRI
MRI does not provide electron density; CT remains the standard for heterogeneity correction. MR-only workflows use synthetic CT (from MR, e.g., Dixon or atlas-based methods) with validated HU/density assignment.
257 words, about 1 min07Treatment Delivery and On-Board MRI Guidance
Understand integrated MR-linac platforms (e.g., 1.5 T and 0.35 T systems) and the workflow: daily setup, on-board MRI, registration to reference, plan adaptation (online or offline), and delivery with real-time imaging. Know gating/tracking using cine MRI and how beam-on gating works.
244 words, about 1 min08Radiation Protection and Professional Practice
Know ALARA, time-distance-shielding, and the distinction between occupational, public, and patient dose limits. Understand the linear no-threshold model, dose quantities (Sv, Gy), and the role of the radiation safety officer and medical physicist.
251 words, about 1 min