PT - JOURNAL ARTICLE AU - Krejza, Jaroslaw AU - Szydlik, Piotr AU - Liebeskind, David S. AU - Kochanowicz, Jan AU - Bronov, Oleg AU - Mariak, Zenon AU - Melhem, Elias R. TI - Age and Sex Variability and Normal Reference Values for the <em>V</em><sub>MCA</sub>/<em>V</em><sub>ICA</sub> Index DP - 2005 Apr 01 TA - American Journal of Neuroradiology PG - 730--735 VI - 26 IP - 4 4099 - http://www.ajnr.org/content/26/4/730.short 4100 - http://www.ajnr.org/content/26/4/730.full SO - Am. J. Neuroradiol.2005 Apr 01; 26 AB - BACKGROUND AND PURPOSE: The index of mean blood flow velocity (V) in the middle cerebral artery (MCA) divided by respective velocity in the ipsilateral internal carotid artery (ICA), or VMCA/VICA index, is commonly used as a marker of vasospasm, although reference values are not established. We sought to provide reference data for these velocities and index.METHODS: Transcranial color-coded duplex and carotid duplex sonography was performed in 335 healthy volunteers (211 women, 124 men; mean age ± SD, 42 ± 18 years; range, 18–86 years). Age analyses were based on three groups: I, &lt;40; II, 40–60; and III, &gt;60 years. The VMCA/VICA index was calculated based on angle-corrected blood flow velocities determined in the MCA and extracranial ICA.RESULTS: Mean flow velocities in the MCA and ICA diminished with increasing age, most pronounced in those subjects &gt;40 years. The VMCA/VICA index increased significantly (1.67 + 0.005 [age]; P &lt; .05) with age in women, but not in men. In women, reference values and ranges for the VMCA/VICA index were as follows, by group: I, 1.82 (range, 0.88–2.68); II, 1.91 (range, 0.94–2.88); and III, 2.06 (range, 0.59–3.53). Respective values for men were as follows, by group: I, 2.10 (range, 0.96–3.24); II, 2.04 (range, 0.71–3.37); and III, 1.78 (range, 0.81–2.75). In subjects &lt;40 years, the VMCA/VICA index was significantly higher in men than in women.CONCLUSION: The VMCA/VICA index significantly varies with age and sex. Sonographic diagnosis of cerebral vasospasm should be based on age- and sex-adjusted reference values of the VMCA/VICA index.