This property leads to more complete spectral analyses and increases the speed at which acoustic windows are found (Moehring and Spencer 2002; Tsivgoulis et al. 2008). This is based on the fact that the average age of our patients was slightly higher than of those evaluated by Marinoni (58.0 ± 20.7 vs. 55.2 ± 16.1) and there was a higher percentage of females in our study. The times used in our evaluations were also shorter than those of other studies (Marinoni et al. 1997). Our Inhibitors,research,lifescience,medical TCD studies were more thorough compared to other experiments (Halsey 1990; Itoh et al. 1993), although

the suboptimal TWs could have been caused by the absence of the ACA, PCA, and/or the TICA. All of these elements may have biased our results toward a higher proportion of inadequate TWs;

in fact, there Inhibitors,research,lifescience,medical was a 10–12% proportion of suboptimal TWs in our study. For the transforaminal window, our proportion of suboptimal windows was similar to that reported by Marinoni et al. (1997), whose Inhibitors,research,lifescience,medical rate of 9.0% compares with our rate of 12.6%; these results were not affected by mechanical ventilation. We found a high success rate for TCD in the transorbital window that is probably explained by the absence of bone between the probe and the Compound C order artery, which is a situation that results in the ultrasound Inhibitors,research,lifescience,medical being neither absorbed nor scattered (Ackerman et al. 1982). The rate of successful TW insonation decreases in females and with advancing age in all population groups (Halsey 1990; Itoh et al. 1993; Marinoni et al. 1997), and the latter factor was the most relevant for our population. This result is in contrast to that reported by Wijnhoud for a European (mostly Caucasian) population, in which gender was the

most important Inhibitors,research,lifescience,medical variable (Wijnhoud et al. 2008). Age clearly affects the detection of ideal TWs in a more dramatic way in females. Women 80 years or older had optimal windows in only 46.1% of the cases, compared with a rate of 72.7% in males from the same age group. This difference is explained by females having thicker temporal bones and more temporal bone inhomogeneity. The latter factor is related to osteoporosis and poorer arterial detection on TCD Histamine H2 receptor (Kwon et al. 2006); some of these anatomical characteristics are shared with African Americans (Halsey 1990). An important finding of our study was that having ideal TWs is dependent only on the patient characteristics and not on environmental elements, the location of the examination, the time of the day, the use of mechanical ventilation, among other factors. This finding is evident because the difference in the time required for our TCD examinations in different settings did not influence the likelihood of having ideal TWs.