Usefulness of transcranial color-coded sonography in the diagnosis of cerebral vasospasm

Background and Purpose-The noninvasive diagnosis of cerebral vasospasm with the use of conventional transcranial Doppler ultrasonography (TCD) is base d on a velocity study of the middle cerebral artery (MCA). The authors repo rt a prospective comparative study between transcranial color-coded sonogra phy (TCCS), conventional transcranial Doppler (TCD), and angiography in the diagnosis of cerebral vasospasm after surgical treatment for aneurysm. Methods-Thirty consecutive patients underwent routine angiography after sur gical treatment for intracranial aneurysm. The distribution of vasospasm wa s determined after a prospective calculation of the angiographic diameter o f the MCA, internal carotid artery (ICA), and anterior cerebral artery (ACA ). The blood flow velocities (systolic and maximum) of the MCA, ICA, and AC A were evaluated by TCCS and TCD. Results-The correlation between mean maximum velocity and angiographic diam eter was significant for the MCA (r=-0.637, P<0.0001), ICA (r=-0.676, P<0.0 001), and ACA (r=-0.425, P<0.01). TCCS sensitivity and specificity were hig her than those for TCD for MCA (100% and 93%, respectively) and ICA (100% a nd 96.6%, respectively). For ACA, the sensitivity and specificity were 71.4 % and 84.8%, respectively. Conclusions-The authors suggest that TCCS is useful for accurate monitoring of cerebral vasospasm in the MCA and ICA. In the ACA, TCCS monitors the he modynamic state of the anterior part of the circle of Willis, which could e xpose the patient to a delayed ischemic deficit.