RVT Preparation, Documentation, and Communication — Questions and Answers
Question 1: Which patient preparation instruction is MOST important before performing a mesenteric arterial duplex examination?
- NPO (nothing by mouth) for at least 6–8 hours prior to the exam (Correct answer)
- Drink 32 oz of water to achieve a full bladder
- No special preparation is required
- Consume a high-fat meal 30 minutes before the scan
Correct answer: NPO (nothing by mouth) for at least 6–8 hours prior to the exam
Bowel gas from food or liquid intake significantly degrades visualization of the celiac axis and superior mesenteric artery. Fasting for 6–8 hours minimizes intraluminal gas and promotes mesenteric vasodilation, improving both image quality and the physiologic significance of post-prandial velocity changes.
Question 2: A vascular technologist performing a surveillance duplex identifies a new, complete thrombotic occlusion of a previously patent femoral-popliteal bypass graft. What is the MOST appropriate immediate action?
- Schedule a 3-month follow-up duplex and note findings in the report
- Communicate the finding urgently to the ordering physician or on-call clinical team before the patient leaves (Correct answer)
- Notify the patient's family and recommend emergency department evaluation
- Repeat the exam in 24 hours to confirm the finding
Correct answer: Communicate the finding urgently to the ordering physician or on-call clinical team before the patient leaves
Acute graft occlusion is a limb-threatening emergency requiring immediate clinical decision-making (thrombectomy, thrombolysis, or revision). The technologist must notify the responsible physician or clinical team while the patient is still present so that timely intervention can be arranged. Documenting without communication causes dangerous treatment delays.
Question 3: Which of the following is considered a REQUIRED component of a complete vascular duplex examination report?
- The technologist's personal clinical impression and treatment recommendation
- Insurance authorization code and billing CPT number
- Clinical indication, technical description of findings, and diagnostic impression (Correct answer)
- Comparison to the patient's prior imaging from outside institutions
Correct answer: Clinical indication, technical description of findings, and diagnostic impression
A complete vascular report must include the reason the study was ordered (indication), a description of the vascular findings with supporting measurements, and a diagnostic conclusion or impression. These elements ensure the referring clinician has the information needed for clinical management.
Question 4: The peak systolic velocity ratio (PSVR) used to grade arterial stenosis severity is calculated as:
- PSV at the stenosis divided by PSV measured distal to the stenosis
- PSV at the stenosis divided by PSV in the adjacent proximal normal arterial segment (Correct answer)
- End-diastolic velocity divided by peak systolic velocity at the stenosis
- Mean velocity at the stenosis divided by resistive index
Correct answer: PSV at the stenosis divided by PSV in the adjacent proximal normal arterial segment
The PSVR compares the elevated velocity at the stenosis to the velocity in the proximal normal (pre-stenotic) segment. This ratio corrects for patient-to-patient variation in cardiac output and overall flow state, making it a more reliable indicator of stenosis severity than an absolute PSV value alone.
Question 5: Which organization specifically accredits vascular ultrasound testing laboratories in the United States for quality standards compliance?
- The Joint Commission (TJC)
- The Intersocietal Accreditation Commission (IAC) (Correct answer)
- The American College of Radiology (ACR) exclusively
- ARDMS (the RVT credentialing body)
Correct answer: The Intersocietal Accreditation Commission (IAC)
The IAC (Intersocietal Accreditation Commission) operates an accreditation program specifically for vascular testing laboratories, evaluating protocols, equipment, personnel credentials, report quality, and QA processes. Many payers and hospitals require IAC accreditation as a condition of reimbursement. ARDMS credentials individuals, not laboratories.
Question 6: When documenting a carotid duplex examination, which finding most accurately represents a 70–99% internal carotid artery stenosis by the Society of Radiologists in Ultrasound (SRU) criteria?
- ICA PSV 100–124 cm/s with no plaque
- ICA PSV ≥ 230 cm/s with ICA/CCA PSV ratio ≥ 4.0 (Correct answer)
- ICA PSV 125–229 cm/s with ICA/CCA ratio < 2.0
- ICA end-diastolic velocity < 40 cm/s with visible plaque
Correct answer: ICA PSV ≥ 230 cm/s with ICA/CCA PSV ratio ≥ 4.0
The SRU consensus criteria define ≥70% ICA stenosis as ICA PSV ≥230 cm/s AND an ICA/CCA PSV ratio ≥4.0, often accompanied by ICA EDV ≥100 cm/s. Using both absolute velocity and the ratio improves accuracy and accounts for hemodynamic variability between patients.
RVT Preparation, Documentation, and Communication
Which patient preparation instruction is MOST important before performing a mesenteric arterial duplex examination?