Comparison of transcranial Doppler ultrasonography and positron emission tomography using a three-dimensional template of the middle cerebral artery.

OBJECTIVE

Transcranial Doppler (TCD) measures blood flow velocities (BFV) and is an indirect method of assessing cerebral blood flow (CBF). Positron emission tomography (PET) is a direct method to measure CBF. This study evaluates the correlations between TCD and PET findings

Methods

Nine patients with a symptomatic carotid artery stenosis, who underwent CEA, were studied pre- and post-operatively on the ipsi- and contralateral sides. Measurements of the BFV, CO(2) reactivity, CBF, cerebral blood volume (CBV) and mean vascular transit time (MVTT) were performed using a three-dimensional volume of interest (VOI) for the middle cerebral artery (MCA).

RESULTS

CBF in the MCA region, as measured with PET, shows a good correlation with BFV, as measured with TCD, with similar pattern for total, gray and white matter MCA territory (Pearson's correlation coefficients: 0.751, 0.748 and 0.748, respectively). This correlation was found in the pre-operative as well as the post-operative state. No association could be demonstrated between CO(2) reactivity and CBV or (Pearson's correlation coefficients: 0.051 and 0.166, respectively).

CONCLUSION

With PET, it is possible to create three-dimensional VOI of arterial territories. CBF measured in these VOI seems to correlate with BFV before and after CEA on ipsi- and contralateral sides, while CBV shows no association with pre-operative CO(2) reactivity.