Every SPI exam question comes from one of five domains in the official ARDMS content outline. ARDMS publishes this outline so candidates know exactly what to expect — and it's the single most useful document you can study before opening a textbook. If you only read one thing before you start preparing, read this.
The current outline took effect in September 2023 and represents a meaningful shift from the previous version. If your school handed you study materials written before that date, some of the domain weightings you were given are out of date. Here's the current breakdown.
The five domains
| Domain | Weight | Approx. questions (of 110) |
|---|---|---|
| 1. Perform Ultrasound Examinations | 23% | ~25 |
| 2. Manage Ultrasound Transducers | 7% | ~8 |
| 3. Optimize Sonographic Images | 26% | ~29 |
| 4. Apply Doppler Concepts | 34% | ~37 |
| 5. Provide Clinical Safety & Quality Assurance | 10% | ~11 |
Two domains — Apply Doppler Concepts and Optimize Sonographic Images — together account for 60% of the exam. That's more than half the test coming from just two of the five domains. If your study time is spread evenly across all five, you are under-preparing for the majority of the exam.
Quick gut check: if you can't confidently work through aliasing, wall filters, sample gate placement, and spectral Doppler measurements, you have a gap in the single largest domain on the exam — worth fixing before test day, not after.
Domain 1: Perform Ultrasound Examinations (23%)
This domain covers the practical side of scanning — patient care, ergonomics, how sound interacts with tissue (echogenicity, reflection, attenuation), gray-scale artifacts like reverberation and shadowing, bioeffects, beam steering, and 3D/4D and contrast imaging concepts. It also includes patient management basics: verifying identity, reviewing history, and documentation standards.
This domain rewards conceptual understanding over memorization. Questions tend to describe a scanning scenario and ask what's happening physically, or what you should do next.
Domain 2: Manage Ultrasound Transducers (7%)
The smallest domain, but don't skip it — at roughly 8 questions, it's still worth more than some people assume going in. Covers transducer selection, frequency tradeoffs, 2D array concepts, 3D/4D transducers, and non-imaging transducer applications (continuous wave Doppler probes, for example).
Because this domain is compact, it's one of the most efficient places to study — a focused review session can cover nearly the entire domain.
Domain 3: Optimize Sonographic Images (26%)
This is where resolution concepts live — axial, lateral, elevational, and temporal resolution, plus frame rate, scan lines, line density, and sector width tradeoffs. It also covers image optimization tools: TGC, harmonic imaging, dynamic range, spatial compounding, edge enhancement, depth, and M-mode.
Many of these concepts interact with each other — increasing frame rate often means decreasing line density or sector width, for example. The exam tests whether you understand those tradeoffs, not just definitions in isolation.
Domain 4: Apply Doppler Concepts (34%)
The largest domain by a wide margin, and the one most students underestimate before they start studying. Covers Doppler angle and the Doppler equation, the Doppler effect and Doppler shift, wall filters, sample gate placement, color priority, color Doppler maps, aliasing and how to eliminate it, continuous wave versus pulsed wave Doppler, color and power Doppler, tissue Doppler, spectral waveform evaluation, Doppler measurements, gain and scale settings for both spectral and color Doppler, and general hemodynamic principles like pressure gradients and resistance.
If you take nothing else from this guide: Doppler is over a third of the exam. A weak grasp of aliasing, the Doppler equation, or wall filter behavior will cost you more points than a weak grasp of almost anything else on the test.
Domain 5: Provide Clinical Safety & Quality Assurance (10%)
Covers infection control protocols, quality assurance documentation, transducer integrity checks, machine integrity verification, gray-scale QA testing with tissue-mimicking phantoms, and statistical concepts like sensitivity and specificity.
This domain tends to be more memorization-based than the others — protocols and definitions rather than applied physics — which makes it a good candidate for flashcard-style review.
How to use this blueprint
A simple, defensible approach: allocate your study time roughly in proportion to domain weight, with a floor for the smaller domains so you don't skip them entirely. In practice, that means Doppler and image optimization should make up well over half of your total study hours, while transducers and clinical safety get focused, efficient review sessions rather than open-ended study time.
It also means your practice exams should mirror this distribution. If a practice test gives every domain equal weight, your score on it won't accurately predict your real exam score — you could do well on a practice test that underweights Doppler and still walk into the real exam underprepared for over a third of the questions.