Contrast-enhanced transcranial color-coded duplexsonography in stroke patients with limited bone windows

BACKGROUND AND PURPOSE: Thickening of the temporal bone in stroke-age patie nts may obviate sonographic evaluation of the circle of Willis in 20% to 30 % of patients. We assessed the diagnostic efficacy of contrast-enhanced tra nscranial color-coded duplexsonography (TCCD) for noninvasive evaluation of the circle of Willis in stroke patients with limited bone windows. METHODS: Of 171 consecutive patients who presented with ischemic symptoms i n the middle cerebral artery (MCA) territory, 49 patients (32 female, 17 ma le; age range, 70.5 +/- 10.6 years) had no detectable colorflow signals fro m the circle of Willis by TCCD because of limited acoustic windows. These 4 9 patients received an IV injection of a sonographic contrast-enhancing age nt, Levovist (Schering; Berlin, Germany), and were re-examined. Correlative imaging studies of the circle of Willis were obtained in 42 of 49 of these patients. RESULTS: In 38 of 49 patients, contrast-enhanced TCCD enabled full visualiz ation of the circle of Willis bilaterally; in an additional five patients, contrast-enhanced TCCD revealed only the portion of the circle of Willis ip silateral to the probe through one temporal bone. In six of these 43 patien ts, contrast-enhanced TCCD showed MCA stenosis and MCA occlusion in three; three of the six cases of MCA stenosis and all three cases of the MCA occlu sion were found on the symptomatic side, In six of 49 patients, no colorflo w signals were obtained after contrast enhancement. All contrast-enhanced T CCD findings were confirmed by CT angiography, transfemoral digital substra ction angiogaphy, MR angiography, or a combination of all three correlative studies. Levovist produced no serious adverse events. CONCLUSION: In stroke-age patients with limited acoustic windows, contrast- enhancement with Levovist can markedly increase the sensitivity of TCCD and increase the detection of clinically relevant intracranial arterial diseas e.