Vascular sonography has three primary credentials: the RVT (Registered Vascular Technologist), the RPhS (Registered Phlebology Sonographer), and the RPVI (Registered Physician in Vascular Interpretation). If you're not a physician, the RPVI isn't your path — but understanding all three clarifies the landscape. Add in the RVS (Registered Vascular Specialist) from CCI and you have four different credentials that employers use inconsistently in job postings.

This guide breaks down each credential, who needs it, and what it actually takes to pass.

The Four Credentials at a Glance

Credential	Issuing Body	Who It's For	Exam Focus
RVT	ARDMS	Vascular sonographers	Peripheral arterial and venous, cerebrovascular, visceral, hemodialysis access
RVS	CCI	Vascular sonographers	Similar to RVT; slightly different eligibility pathway
RPhS	ARDMS	Phlebology-focused sonographers	Venous duplex for varicose vein treatment planning
RPVI	ABVLM	Physicians and APPs	Vascular interpretation (MD/DO/NP/PA only)

For practicing vascular sonographers, the decision is primarily RVT vs. RVS, with RPhS as a possible add-on for those in phlebology practices.

RVT (Registered Vascular Technologist) — ARDMS

The RVT is the gold standard in vascular sonography, the most widely recognized credential by hospitals and vascular surgery practices.

Eligibility Requirements (2026)

Pathway 1: Graduate of a CAAHEP-accredited program with a vascular technology track.

Pathway 2: 12 months of clinical ultrasound experience in vascular technology + meet one of:

Allied health credential (RDMS, RDCS, RT, RN, etc.)
Graduate of any accredited healthcare educational program

Required exams:

SPI (Sonography Principles and Instrumentation) — prerequisite exam covering ultrasound physics
VT (Vascular Technology) specialty exam — the clinical content examination

Both exams are computer-based, administered at Pearson VUE testing centers.

SPI Exam

110 questions, 2 hours
Topics: ultrasound physics, instrumentation, hemodynamics, Doppler principles, image quality optimization
Pass rate (2024): ~73% first attempt
Fee: $195

Key content areas:

Piezoelectric effect and transducer construction
A-mode, B-mode, M-mode, Doppler (pulsed, continuous wave, color, power)
Beam properties: resolution, focal zone, near-field/far-field
Artifacts: shadowing, enhancement, reverberation, mirror image, aliasing
Hemodynamics: flow patterns, Bernoulli principle, spectral waveform analysis

VT Specialty Exam

170 questions, 3 hours
Pass rate (2024): ~68% first attempt
Fee: $275

Content domains (approximate weighting):

Domain	Approximate %
Peripheral arterial disease (lower extremity)	22%
Cerebrovascular disease (carotid, vertebral, TCD)	20%
Peripheral venous disease (DVT, CVI, saphenous mapping)	22%
Visceral vascular (mesenteric, renal, aortoiliac, portal)	16%
Hemodialysis access mapping and surveillance	10%
Intracranial/intrathoracic/misc.	10%

Clinical reference standards tested:

Carotid stenosis: SRU 2003 consensus criteria (PSV thresholds for 50–69%, 70–99%)
DVT: Compressibility criteria, augmentation, phasicity, spontaneous flow
Lower extremity arterial: ABI interpretation (normal >1.0, borderline 0.9–1.0, mild PAD 0.7–0.89, moderate 0.4–0.69, severe <0.4), segmental pressures, toe-brachial index
Renal artery stenosis: RAR (renal-to-aortic ratio) >3.5, acceleration time >100ms, tardus parvus waveform
Celiac/SMA: Peak systolic velocity thresholds for stenosis

SonoBuddy's vascular measurement reference tables cover these thresholds. Know the numbers cold before exam day.

RVT Study Resources

ARDMS Practice Exams — available at ardms.org; expensive but closest to actual exam format
SoundPrint Vascular Technology Review — widely used, comprehensive question banks
Pegasus Lectures Physics and Instrumentation — thorough physics course for SPI prep
Davies Publishing Review Book — classic text, covers all content areas
Zierler & Zierler: Strandness's Duplex Scanning in Vascular Disorders — clinical reference, good for visceral vascular

RVS (Registered Vascular Specialist) — CCI

The RVS from Cardiovascular Credentialing International covers similar clinical content to the RVT.

Differences from RVT

Factor	RVT (ARDMS)	RVS (CCI)
Recognition in hospital job postings	Near-universal	Common; some older postings list only RVT
Combined cardiac/vascular track	Separate exams	RCCS (combined echo/vascular) option exists
Maintenance of certification	CME-based	CME-based
Exam fee	$275 + $195 (SPI)	$250

CCI eligibility: Requires graduation from a cardiovascular technology program or completion of clinical hours in vascular technology plus documentation of supervised case experience. CCI eligibility requirements differ slightly from ARDMS — check cci-online.org directly for current specifics.

Who should get RVS instead of or in addition to RVT?

Cardiovascular technologists who already hold CCI credentials (RCCS, RCS, RCES) and want to add vascular — the CCI ecosystem is already familiar
Some larger cardiac programs prefer CCI credentialing for their combined echo/vascular technologists

In practice: Most vascular lab job postings accept either RVT or RVS. Cardiac cath labs and cardiology-affiliated practices may show CCI preference.

RPhS (Registered Phlebology Sonographer) — ARDMS

The RPhS is a subspecialty credential for sonographers working in phlebology (vein) practices — venous ablation centers, cosmetic vein clinics, and interventional phlebology offices.

What It Certifies

Scope is narrower than RVT:

Superficial venous duplex (great saphenous vein, small saphenous vein, accessory veins)
Saphenous vein mapping for ablation planning
Perforating vein assessment
Post-procedure surveillance
DVT evaluation (lower extremity)

Does NOT cover arterial disease, cerebrovascular, hemodialysis access, or visceral vascular.

Who Should Get RPhS

Sonographers working exclusively in vein clinics who don't want or need the full RVT scope
Existing RDMS or RVT holders adding a phlebology subspecialty credential
Medical assistants at vein practices who have been doing duplex scanning and want to formalize their credentials

Eligibility: Requires documentation of phlebology ultrasound clinical hours (typically 500 hours in venous duplex). See ardms.org for current specifics.

Exam fee: $275 + SPI prerequisite if not already held.

Salary impact: RPhS alone is not a substitute for RVT in most settings. In vein-specific practices, it may be the primary credential required — and those practices often pay competitive rates due to the specialized nature of the work.

Maintaining Your Credentials

All ARDMS credentials require Continuing Medical Education (CME) for renewal:

Renewal Cycle	CME Required	Cost
Every 3 years	30 ARDMS-approved CME credits	~$100–$200 for CME courses; renewal fee ~$140

CME sources accepted: SDMS conferences and online modules, AIUM, SVU (Society for Vascular Ultrasound) annual conference, SonoBuddy-credited courses when applicable, hospital grand rounds with documentation.

The SVU annual conference is one of the best single sources of vascular-specific CME — 3–4 days typically yields 15–20 CME credits plus significant clinical learning.

Which Credential to Pursue First

If you're a new sonographer entering vascular: → RVT first. It's the most universally recognized and opens the most doors. Pass the SPI first, then the VT specialty exam.

If you're already an RDMS considering adding vascular: → RVT. Your SPI is likely already satisfied; you only need the VT specialty exam.

If you work in a vein clinic and nowhere else: → RPhS may be sufficient — confirm with your employer what they accept for credentialing.

If you're a cardiovascular tech with CCI credentials: → RVS makes practical sense to stay within the CCI credentialing ecosystem.

Salary Impact of RVT Credential

Based on job posting analysis and SDMS salary survey data (2025):

Credential Status	Median Hourly Rate
Unregistered sonographer (vascular experience)	$28–$38/hr
RVT or RVS (entry-level position)	$36–$50/hr
RVT + 3+ years vascular experience	$48–$68/hr
RVT + additional specialty (RDMS or RDCS)	$55–$80/hr
Vascular lab supervisor/director (with RVT)	$75,000–$110,000/yr (salaried)

The RVT credential typically adds $4–$8/hour over unregistered rates in direct comparison. In high-demand markets (coastal metros, underserved regions), the premium can be higher because supply is limited.

Vascular Sonographer Certification Guide: RVT, RPhS, and RPVI Explained