"insonation: place the probe over the mid-cervical spine (typically C4-C6 levels) to locate the intertransverse segment of the vertebral artery 3"
"bilateral check: repeat the rotational movements while tracking the contralateral side, as upper cervical (C1-C2) compression commonly reduces contralateral flow, while lower subaxial (C5-C7) lesions affect ipsilateral flow 1,4"
"bilateral check: repeat the rotational movements while tracking the contralateral side, as upper cervical (C1-C2) compression commonly reduces contralateral flow, while lower subaxial (C5-C7) lesions affect ipsilateral flow 1,4"
Expected headings
"Patient and equipment setup"
"Technique"
"Diagnostic criteria"
"CT / MRI"
"transducer: high-frequency (7.5-10 MHz) linear array probe for cervical segments; lower-frequency sector/curved array if deeper penetration is needed"