Exam logistics
The ARDMS SPI Exam: Format, Domains, Scoring & How to Register
Everything you need to book and sit the SPI: how it is delivered, how it is scored, the five content domains by weight, and the ARDMS → Pearson VUE path to a seat. Where a number can change — fee, question count, pass mark, dates — we point you to ARDMS’s own site (ardms.org) instead of quoting something that may already be stale.
What the SPI is — and who has to take it
The SPI (Sonography Principles and Instrumentation) is the ultrasound-physics exam shared across ARDMS credentials. You pass SPI plus a specialty exam and the pair earns you an RDMS, RDCS, or RVT. SPI is the physics half; the specialty exam is the anatomy-and-pathology half. If you are on an ARDMS pathway, SPI is almost certainly on your list.
Format at a glance
| What | The SPI |
|---|---|
| Delivery | Computer-based, at a Pearson VUE test center. Any remote or at-home option is set by ARDMS — confirm what is currently offered straight from ARDMS. |
| Question format | Multiple-choice, one best answer. Expect calculation items (Doppler shift, Bernoulli pressure gradient, acoustic impedance) alongside straight concept questions. |
| Number of questions | Set by ARDMS and subject to change — do not trust a fixed number you read on a forum; get the current count from ARDMS. |
| Scoring | A scaled score, not a raw percentage. ARDMS converts your performance to a scaled value and reports pass or fail. |
| Passing standard | A scaled cut score published by ARDMS. The exact value can change; verify it against ARDMS's published standard. |
| Time limit | Fixed and enforced at the test center. Check the current allotment with ARDMS before you book. |
| Cost | Set by ARDMS. Verify the current fee on ARDMS's own site (ardms.org) — we do not quote a price that may be out of date. |
| Result | Delivered per ARDMS's current process (typically at the end of your session and through your ARDMS account). |
The five content domains, by weight
| SPI domain | Exam weight |
|---|---|
| Apply Doppler Concepts | 34% |
| Optimize Sonographic Images | 26% |
| Perform Ultrasound Examinations | 23% |
| Provide Clinical Safety & Quality Assurance | 10% |
| Manage Ultrasound Transducers | 7% |
How to register: ARDMS application → Pearson VUE scheduling
Apply through ARDMS
Eligibility runs through your education and clinical background. Prerequisites are set by ARDMS — check which pathway fits you on ARDMS's site before you pay anything.
Get your authorization to test
Once ARDMS approves your application you receive authorization to schedule. Nothing books until this clears.
Schedule at Pearson VUE
Pick a test center and a seat through Pearson VUE. Book early for the location and date you want — popular centers fill up.
Test day
Bring the ID ARDMS specifies, arrive early, and expect check-in and security screening. It is a physics exam on a computer: one best answer per item, calculator provided on screen.
Get your result
You receive a pass or fail outcome per ARDMS's current reporting process. A failed attempt is not the end — see retakes below.
If you don't pass: retakes
Failing the SPI is common enough that ARDMS has a standard retake path — it is a physics exam, and plenty of capable sonographers clear it on a second attempt. There is a waiting period between attempts and a retake fee; both are set by ARDMS and change from time to time, so confirm the current window and cost with ARDMS rather than trusting a number from a forum. Use the wait: re-drill Doppler and image optimization, because that is where a failing score usually leaks points.
Score report basics
Your result comes back as a scaled value with a pass-or-fail decision, not a raw percentage. You cannot back-calculate "how many did I miss" from the number, and you should not try. On a failed attempt ARDMS typically reports a breakdown by content domain — read that breakdown, because it tells you exactly which of the five domains to re-hit before you rebook.
SPI exam FAQ
Is the ARDMS SPI exam difficult?
It is a physics exam, so it rewards understanding relationships — frequency versus penetration, angle versus Doppler shift — over memorizing trivia. People who drill the calculations and the artifact families tend to find it fair; people who only read tend to get surprised. Check ARDMS directly for current expectations.
How many questions are on the SPI?
ARDMS sets the count and can change it, so we don't publish a fixed number here. Verify the current figure with ARDMS. What matters more for your score is the domain weighting: Doppler and image optimization dominate.
Can I take the SPI at home?
The SPI is delivered at Pearson VUE test centers. Any remote or online-proctored option is entirely ARDMS's call and can change — confirm what is currently offered on ARDMS's site (ardms.org) before you plan around it.
What happens if I fail the SPI?
You wait out ARDMS's required interval, pay the retake fee, and rebook through Pearson VUE. Both the waiting period and the fee are set by ARDMS — verify them with ARDMS directly. Read your domain breakdown first: it tells you where the points leaked.
SPI prep in your pocket
Stop reading about the exam — start drilling it
A free, timed console weighted like the real SPI. Or take it with you on the app.