Page 138 - Libro 2

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PART 2 — CEREBROVASCULAR
SUMMARY
Intracranial cerebrovascular examinations with transcranial Doppler techniques can provide a vast amount of anatomic and physiologic data. The examination of the intracranial vessels requires extensive knowledge of anatomy and meticulous atten- tion to technique. Various disease states can be evaluated with transcranial Doppler or transcranial imaging. A thorough understanding of the intracranial vessels will aid in the successful evaluation of patients presenting with suspected intracranial vascular disease.
Critical Thinking Questions
1. A TCD needs to be performed on a hospital inpatient that cannot be placed in a lateral decubitus position. Can the VAs and BA still be insonated and, if so, how?
2. While reviewing images from a TCD exam, should one expect to observe low resistance or high resistance signals?
3. When scanning via the transtemporal approach, two vessels are observed that appear to have branches. In order to determine which vessels are in view, what additional information needs to be taken into consideration?
4. A patient will require continued monitoring of MCA velocities. Which type of ultrasound probe would be best for this application and why?
REFERENCES
1. Aaslid R, Markwalder TM, Nornes H. Noninvasive transcranial Doppler ultrasound recording of flow velocity in cerebral arteries. J Neurosurg. 1982;57:769–774.
2. von Reutern GM, von Budingen HJ. Ultrasound Diagnosis of Cerebrovascular Disease. New York, NY: Thieme Medical Publishers; 1993.
3. Gabrielsen TO, Greitz T. Normal size of the internal carotid, middle cerebral and anterior cerebral arteries. Acta Radiol Diagnosis. 1970;101:68–87.
4. Lang J. Neurokranium, orbita, kraniozervikaler ubergang [Neurocranium, orbit, craniocer- vical transition]. Klinische Anatomie des Kopfes. [Clinical anatomy of the head]. Berlin, Germany: Springer; 1981.
5. Hodes PJ, Campy F, Riggs HE, et al. Cerebral angiography: fundamentals in anatomy and physiology. Am J Roentgenol. 1953;70:61–82.
6. Taveras JM, Wood EH. Diagnostic Neuroradiology. Baltimore, MD: Williams and Wilkins; 1976.
7. Alexandrov AV, Sloan MA, Wong LKS. Practice standards for transcranial Doppler ultra-
sound: part I—test performance. J Neuroimaging. 2006;17:11–18.
8. Alexandrov AV, Demchuk AM, Wein TH, et al. The yield of transcranial Doppler in acute
cerebral ischemia. Stroke. 1999;30:1605–1609.
9. Spencer MP, Whisler D. Transorbital Doppler diagnosis of intracranial arterial stenosis.
Stroke. 1986;17:916–921.
10. Aaslid R, ed. Transcranial Doppler Sonography. New York, NY: Springer-Verlag; 1986.
11. Arnolds BJ, von Reutern MG. Transcranial Doppler sonography. Examination techniques
and normal reference values. Ultrasound Med Biol. 1986;12:115–123.
12. Lindegaard KF, Nornes H, Bakke SJ, et al. Cerebral vasospasm diagnosis by means of
angiography and blood velocity measurements. Acta Neurochir. 1989;100:12–24.
13. Lindegaard KF. The role of transcranial Doppler in the management of patients with
subarachnoid haemorrhage: a review. Acta Neurochir. 1999;72:59–71.
14. Soustiel JF, Shik V, Shreiber R, et al. Basilar vasospasm diagnosis: investigation of a modified “Lindegaard Index” based on imaging studies and blood velocity measurements of
the basilar artery. Stroke. 2002;33:72–77.