ASN CNSA study guide
ASN CNSA · Work through your exam, one topic at a time.
The American Society of Neuroimaging (ASN) describes certification as a way to "recognize advanced expertise and professional achievement" for neuroimaging professionals, and its site lists two currently offered credentials: Neurosonology (RPNI) and Neurovascular Specialist (NVS). A separate "Neuroimaging Examination" is announced on the ASN site as "Coming 2027!" and is not yet available, so candidates today should plan around RPNI or NVS. The ASN describes itself as representing "clinicians, researchers, and technologists worldwide" and as having advanced education, certification, and collaboration in neuroimaging since 1977, which suggests the certifications are aimed at practicing physicians, sonographers, and technologists who already perform or interpret neuroimaging studies. Preparation should center on supervised hands-on scanning and interpretation experience plus the reading and continuing-education resources the ASN publishes, including its journal, monthly newsletter, webinars, and Educational Rounds. Topics on this exam: Neurosonology (RPNI) and Neurovascular Specialist (NVS). The ASN CNSA study guide has 2 sections and about 656 words.
01Neurosonology (RPNI): Intracranial Hemodynamics and Waveform Interpretation
Neurosonology questions test whether you can translate a Doppler waveform into a physiologic statement about the vessel and the brain it supplies. Know the insonation windows (transtemporal, transorbital, suboccipital, submandibular), the depth and direction conventions for MCA, ACA, PCA, basilar, and vertebral arteries, and normal mean flow velocities (roughly 40–60 cm/s in the MCA in adults, dropping with age). Understand resistance patterns: low-resistance internal carotid and vertebral beds versus the higher-resistance external carotid. Be fluent in the vocabulary of stenosis - focal velocity elevation, spectral broadening, turbulence, post-stenotic disturbance - and in vasospasm after subarachnoid hemorrhage, where velocities rise segmentally without a focal plaque.
334 words, about 2 min02Neurovascular Specialist (NVS): Carotid and Vertebral Duplex Interpretation
NVS questions blend anatomy, hemodynamics, and clinical correlation. Master the carotid bifurcation: common carotid divides into internal (low resistance, no branches in the neck) and external (higher resistance, branches). Know how to identify the ICA versus ECA by waveform, branch anatomy, and response to tapping the superficial temporal artery. Understand plaque characterization - echogenicity, surface regularity, ulceration - and how stenosis is graded by peak systolic velocity, end-diastolic velocity, and the ICA/CCA ratio.
322 words, about 2 min