Brain perfusion evaluated by perfusion-weighted magnetic resonance imaging before and after stenting internal carotid artery stenosis in asymptomatic and symptomatic patients

Abstract

Purpose

To evaluate the brain perfusion with MRI perfusion weighted imaging (PWI) before and after ICA stenting in asymptomatic and symptomatic patients.

Materials and methods

PWI was performed 3–21 days before and 3 days after ICA stenting in 31 asymptomatic patients with ICA >70% stenosis – Group I, and in 14 symptomatic patients with ICA >50% stenosis – Group II. PWI was evaluated qualitatively and quantitatively in 5 cerebral territories with: mean transit time (MTT), cerebral blood volume (CBV) and cerebral blood flow (CBF). Mean values of perfusion parameters were measured before and after stenting ΔMTT, ΔCBV, ΔCBF were calculated as subtraction of after-treatment values from those before treatment.

Results

In qualitative evaluation after ICA stenting perfusion was normalized in 21 patients (80.8%) in Group I and in 8 patients (80%) in Group II.

In quantitative estimation MTT decreased significantly after CAS on stented side vs. non-stented side in all examined patients regardless of the group, p<0.05. MTT decreased more in Group II than in Group I in all territories (p<0.05) with the exception of temporal lobe. CBV and CBF have shown insignificant differences.

Conclusions

1.In MRI the most useful parameters to assess brain perfusion are MTT and ΔMTT: regardless whether patients are asymptomatic or symptomatic.2.There were no significant differences in CBV and CBF after stenting in both groups of patients.3.The positive effect of ICA stenting measured with decrease of MTT, CBV values and increase of CBF value is more prominent in symptomatic patients.