Diagnostic benefit of echocontrast enhancement for the insufficient transtemporal bone window

Echocontrast agents (ECA) are known to improve transcranial color-coded dup lex (TCCD) imaging, but its diagnostic benefit in the routine clinical sett ing has not clearly been defined. The authors investigated the diagnostic b enefit of ECA application in 54 patients with insufficient transtemporal bo ne window, consecutively referred to their ultrasound laboratory. According to the precontrast imaging quality, patients were assigned to three catego ries: A, no intracranial structures or vessel segments visible on B-mode im aging and TCCD (n = 5); and intracranial structures visible on B-mode imagi ng and Vessel segments less than 5 mm in length (B, n = 21), or larger than 5 mm in length (C, n = 28) visible on TCCD. The effect of the echocontrast enhancement was assessed with respect to signal enhancement, imaging quali ty, and diagnostic confidence. In 49 out of 54 patients (91%), a significan t improvement of the imaging quality was noted, enabling 43 (80%) neurovasc ular diagnoses of sufficient diagnostic confidence. The diagnostic ECA effe ct was strongly dependent on the precontrast imaging quality: upon echoenha ncement, a satisfactory image quality was obtained in none of the patients of category A, as opposed to 16 (76%) and 27 (96%) patients of categories B and C, respectively. in summary, in 80% of our consecutive patient series with insufficient transtemporal bone window, application of ECA allowed for a conclusive TCCD study. Properties of the transtemporal precontrast scans are strongly predictive of the diagnostic benefit and should be taken into the decisive consideration.