About · SPI physics console
About This SPI Study Resource
We are a small, independent study-tools team that builds one thing well: free practice for the ARDMS SPI (Sonography Principles and Instrumentation) exam. No course to upsell, no textbook to move — just the physics that carries the points.
What we actually do
SPI is the ultrasound-physics half of registry certification. Pass it alongside a specialty exam and you earn a credential like RDMS, RDCS, or RVT. Physics is where most people bleed study time, because it is easy to try to learn everything — every transducer variant, every artifact, every edge-case number — and retain none of it.
Our whole job is the opposite of that. We rank the exam by where the points actually live, build timed questions weighted to those domains, and tell you — in plain language, in the answer rationales — what to memorize and what you can safely skip. That is the entire editorial stance of this site.
You cannot study twelve hours a day and keep any of it. Study the domains that carry the points, drill them until they are automatic, and let the long tail go.
Weight equals points
The SPI exam is not evenly distributed, so your studying should not be either. A handful of domains carry most of the score; the rest are worth so little that missing every question in them will not, on its own, fail you. Here is how heavily we weight our own question bank, mirrored to the exam's published content outline:
ARDMS publishes the authoritative content outline, and the exact percentages can be revised over time — always confirm the current breakdown on ARDMS's own site (ardms.org). What does not change is the principle: the biggest domains are worth the most, so they get studied first.
How we build the content
Nothing here is guessed. The pipeline is deliberately boring:
Start from the blueprint
We take the SPI domains and their exam weights and let them decide how much of each topic a representative practice set should contain.
Draw from a real question bank
Practice items come from a large, curated bank built for ultrasound-physics prep, sampled in proportion to those domain weights — a mock test, not a random pile.
Write plain-language rationales
Every answer explains not just why it is right but whether the fact is worth memorizing or safe to punt. That triage is the point of the whole site.
Keep it free and fast
The practice runs in your browser with no signup and no paywall. The optional companion app is there if you want to drill on your phone — that is the only ask.
Not affiliated with ARDMS
SPI prep in your pocket
Put the weighting to work
Timed SPI questions, drawn heaviest-domain-first, with a rationale after every answer. Free on this site, or drill on your phone.