OB/GYN vs VT: ARDMS Exam Comparison
This page compares the ARDMS Obstetrics & Gynecology (OB/GYN) and Vascular Technology (VT) exams side by side. They differ in clinical scope, content focus, career setting, and 2025 pass-rate data.
OB/GYN vs VT: Exam Comparison
| Factor | Obstetrics & Gynecology (OB/GYN) | Vascular Technology (VT) |
|---|---|---|
| Credential earned | RDMS | RVT |
| Question count | 170 | 170 |
| Exam duration | 3 hours | 3 hours |
| Passing score | 555/700 | 555/700 |
| 2025 first-time pass rate | 80% | 70% |
| 2025 repeat pass rate | 50% | 45% |
| 2025 overall pass rate | 75% | 63% |
| Difficulty level | Easier | Hard |
Source: ARDMS/APCA Global Exam Performance Summary Report, 2025. First-time and repeat rates describe different candidate groups and do not by themselves establish exam difficulty.
About the Obstetrics & Gynecology (OB/GYN) Exam
The ARDMS OB/GYN specialty exam has the highest first-time pass rate among all seven specialties (80% in 2025), but its content breadth is substantial. It covers the full spectrum of obstetric and gynecologic ultrasound: normal and abnormal pregnancy, fetal anatomy survey, biometry, Doppler surveillance, and gynecologic pathology.
About the Vascular Technology (VT) Exam
The ARDMS Vascular Technology (VT) specialty exam earns the Registered Vascular Technologist (RVT) credential. It has the lowest first-time pass rate among all seven specialties (70% in 2025) and tests a deep understanding of hemodynamics, Doppler physics, carotid stenosis criteria, DVT protocols, peripheral arterial disease, and abdominal vascular assessment.
Key Topics Compared
OB/GYN Key Topics
- First trimester assessment
- Fetal biometry
- Placental evaluation
- Amniotic fluid assessment
- Ectopic pregnancy
- Uterine pathology
- Ovarian pathology
- Cervical assessment
- Multiple gestation
- Fetal anatomy survey
- Growth restriction
- Gynecologic imaging
VT Key Topics
- Carotid duplex
- Vertebral artery assessment
- DVT evaluation
- Arterial duplex
- ABI and segmental pressures
- Venous insufficiency
- Abdominal aorta
- Renal artery stenosis
- Mesenteric arteries
- Hemodialysis access
- Hemodynamic principles
- Doppler physics
Among 2025 candidates, OB/GYN first-time and repeat pass rates were 80% and 50% (a 30-point gap); VT rates were 70% and 45% (a 25-point gap). These are separate groups, not a measure of individual improvement.
Which Exam Should You Take First?
The right choice depends on your clinical background, your current employer's needs, and your long-term career goals. Sonographers with strong clinical experience in obstetrics & gynecology imaging should consider the OB/GYN exam first, as applied clinical knowledge transfers directly to board performance. Similarly, those working predominantly in vascular technology settings will find the VT exam more immediately supported by their daily practice.
- Career goals: The RDMS (OB/GYN) and RVT (VT) serve different clinical roles. Consider which aligns better with your desired work environment.
- Pass rate confidence: With a 80% first-time pass rate, OB/GYN may be a confidence-building first exam if you are early in your career. These rates compare separate candidate groups, not the inherent difficulty of an exam.
- Clinical experience: Take the exam that aligns with your strongest clinical rotations or work experience. Hands-on scanning experience impacts exam readiness.
- Prerequisite: Both specialty credentials require a passing SPI score. If you haven't taken the SPI yet, that should be your first priority regardless of specialty choice.
Both exams reward structured, domain-aligned preparation. The VT first-time pass rate is 70% compared with 80% for OB/GYN; use these cohort results as context rather than a prediction of your individual outcome.