Detection of intracranial aneurysm using transcranial color-coded duplex sonography with echo contrast agent

Abstract

Purpose: It has been suggested that intracranial aneurysms could be observed using transcranial color-coded duplex sonography (TCDS). We investigated the sensitivity of TCDS studies for detecting unruptured aneurysms both with and without an echo contrast agent. Methods: We studied 39 patients (44 aneurysms) who were diagnosed as having unruptured intracranial aneurysms by cerebral angiography (36 patients) or MRA (3 patients). We performed TCDS both with and without echo contrast agents in all patients. In 7 patients who underwent endovascular treatment for unruptured intracranial aneurysms, enhanced TCDS studies were done both before and after the treatment. Results: Because of an insufficient transtemporal bone window, intracranial cerebral arteries were not visible with TCDS in 3 patients, despite enhancement by echo contrast agents. Among the 36 patients (38 aneurysms) whose intracranial cerebral arteries could be evaluated by TCDS, 13 cerebral aneurysms were detected (34%) without the aid at echo contrast agents. After echo contrast agents were administered, 9 additional aneurysms were observed by TCDS studies and the sensitivity of the test resulted in 58%. The sensitivity of enhanced TCDS for detecting cerebral aneurysms in the internal carotid artery, middle cerebral artery, anterior cerebral artery or anterior communicating artery, and basilar artery was 46%, 80%, 17%, and 67%, respectively. The frequency of larger aneurysms detection (>5 mm) was significantly higher (78%) than that of smaller ones (<5 mm; 40%). In all the patients who underwent endovascular treatment, cerebral aneurysms that had been observed by enhanced TCDS were not detected after the treatment. Conclusions: TCDS may be suitable for the detection as well as follow-up study of intracranial aneurysms. The sensitivity of this noninvasive study is drastically improved by contrast agents.