Transcranial Duplex Imaging With a Sulfurhexafluoride Echocontrast Agent: Enhancement and Diagnostic Quality

Background and Purpose. The authors investigate characteristics of ultrasound enhancement and diagnostic quality of a sulfurhexafluoride(SF6)-containing echocontrast agent (SonoVue™) in cerebrovascular patients with insufficient temporal bone window by transcranial color-coded duplex (TCCD) sonography. Methods. Thirty patients (mean age = 62.2 ±11.1 years) were enrolled. SF6 was administered intravenously in 4 different doses (0.3, 0.6, 1.2, and 2.4 mL). By videotape analysis, time to contrast appearance, duration of contrast enhancement, and duration of clinically useful signal enhancement were measured. Overall quality of ultrasound investigation was also assessed. Results. Time to contrast appearance ranged from 11 to 74 seconds (mean = 26 seconds). For the 0.3, 0.6, 1.2, and 2.4 mL doses, average times to contrast appearance of 30 ±12 seconds, 28 ±10 seconds, 23 ±8 seconds, and 22 ±6 seconds were measured. Duration of TCCD signal enhancement was 438 ±169 seconds, 483 ±195 seconds, 713 ±299 seconds, and 788 ±344 seconds for the different doses. Clinically useful enhancement was 160 ±124 seconds, 200 ± 157 seconds, 260 ±166 seconds, and 327 ±239 seconds. Conclusions. Administration of SonoVue led to a quality improvement in 21 patients. In TCCD, it optimizes visualization of the cerebral arteries in patients with inadequate bone window. A dose of at least 1.2 mL provides the best enhanced images.