Repetition of color Doppler ultrasonography: is it necessary?

The aim of the study was to determine whether any difference would occur in peak systolic velocity (PSV) and end diastolic velocity (EDV) measurements of color Doppler ultrasonography (CDU) between proximal and distal segments of the cavernous arteries obtained at different times. Twenty-six cases have undergone CDU three times in weekly intervals. PSV and EDV measurements of cavernous arteries were obtained both proximally and distally. The results have shown that statistically there was no difference between each measurement obtained on either sides at three different tests. (ANOVA PSV F(2-50) = 0.63, EDV F(2-50) = 0.81). Four of the 26 cases had different PSV results and six cases had different EDV results in three CDU tests. There was a statistical difference in measurements between proximal and distal segments of the cavernous arteries. (t-test t = 2.53, P = 0.015) In conclusion, repetition of CDU would not be necessary in majority of the cases. However investigators should always be aware and cautious about falsely abnormal results of CDU. Proximal segments of the cavernous arteries should be the site to obtain true CDU measurements.