DIAGNOSIS AND MONITORING OF MIDDLE CEREBRAL-ARTERY OCCLUSION WITH CONTRAST-ENHANCED TRANSCRANIAL COLOR-CODED REAL-TIME SONOGRAPHY IN PATIENTS WITH INADEQUATE ACOUSTIC BONE WINDOWS

Transcranial color-coded real-time sonography (TCCS) is an emerging di agnostic technique that allows noninvasive imaging of intracranial ves sels within parenchymal structures. However, in some patients, transcr anial ultrasound is particularly hindered by insufficient ultrasound p enetration through the temporal bone. The present study evaluates whet her or not application of an echo-contrast agent in ultrasound-refract ory patients with middle cerebral artery (MCA) trunk occlusion enhance s image acquisition enough to yield accurate diagnoses. Contrast-enhan ced (CE) TCCS examinations, computed tomography scans and angiographic studies were performed in 20 patients with clinical symptoms suggesti ve of MCA occlusion within 12 h of the onset of symptoms. For comparis on, 20 control persons without history or clinical signs for cerebrova scular diseases were examined using CE-TCCS. In none of the patients o r control subjects did unenhanced TCCS investigations depict any color -coded vascular signal of an intracranial vessel. After application of 9 mt of 400 mg/mL galactose-based microbubbles, CE-TCCS was performed . In subjects with MCA occlusion, CE-TCCS examinations were repeated w ithin 24 h, 48 h and 5 days after stroke. In stroke patients (n = 20), CE-TCCS showed an occluded MCA main stem in 11 patients, and this ves sel was clearly demonstrable on the unaffected side. On the affected s ide, the posterior cerebral artery (PCA) and anterior cerebral artery (ACA) could be visualized in 8 of 11 subjects; in 3 patients, at least 1 of these vessels was detectable. Angiographic studies confirmed the diagnosis of MCA trunk occlusion in all 11 individuals. In follow-up investigations, 3 stroke patients had angiographic and CE-TCCS examina tions consistent with vessel reperfusion. Nine stroke patients had a p atent MCA shown in angiographic and CE-TCCS examinations. In the contr ol group, the MCA trunk could be visualized in all subjects by CE-TCCS . CE-TCCS is a sensitive and specific ultrasound method for the diagno sis of MCA trunk occlusion that overcomes the anatomical hindrance of inadequate acoustic bone window. This technique may help to identify p atients suitable for thrombolytic therapies and monitor their response . (C) 1998 World Federation for Ultrasound in Medicine & Biology.