Page 117 - Libro 2

7 — Intracranial Cerebrovascular Examination 97
AB
Figure 7-6 A: Obtaining the submandibular ICA at the angle of the jaw. B: Insonation of the vertebral artery in the region of the atlas loop.
Standard TCD exams are performed on inpatients and outpatients when ordered. A complete stan- dard TCD exam consists of pulsed wave Doppler in- sonation of the basal cerebral arteries including the bilateral cavernous and terminal segments of the ICAs, OAs, MCAs, ACAs, PCAs, VAs, and the BA.8 Additionally, in some populations, the extracranial
TABLE 7-1
retromandibular ICAs and VAs at the atlas loop will be examined to calculate vasospasm ratios (Table 7-1).
Doppler spectral waveforms are acquired in a blind fashion without the aid of B-mode or color Doppler, requiring a good understanding of the anatomy and physiology of the intracranial vessels and a precise, systematic approach to the exam performance.
Basal Cerebral Arteries Insonated during Intracranial Exam, Their Abbreviations, and the Minimum Documentation for a Complete, Normal TCD or TCDI Study
Number of
Artery AbbreviationsWaveformsComments
Ophthalmic OA 1 Carotid siphon CS 3
Terminal internal carotid TICA 1 Middle cerebral MCA and MCA2 3
Anterior cerebral ACA 1 (precommunicating segment)
Anterior cerebral ACA2 1 (postcommunicating segment)
Anterior communicating artery ACOA 1 Posterior cerebral PCA1 1
(precommunicating segment)
Posterior cerebral PCA2 1
(postcommunicating segment)
Posterior communicating artery PCOA 1 Submandibular internal carotid SM-ICA 1
artery
Vertebral VA4 3 Vertebral at the atlas loop (V3) VA3
Basilar BA 3
C2 (supraclinoid), C3 (genu), C4 (parasellar) if accessible
C1
Proximal, mid, and distal, including MCA2 branches
Only applies to TCDI
When functioning as collateral
When functioning as collateral
When calculating Lindegaard index or
documenting distal narrowing
Proximal, mid, and distal
When calculating Sviri ratio for vasospasm Proximal, mid, and distal