To determine whether computed tomography perfusion imaging (CTPI)-derived parameters are associated with vascular cognitive impairment (VCI) in patients with transient ischemic attack (TIA). Patients with first-time anterior circulation TIA (diagnosed within 24 h of onset) and normal cognition, treated between August 2009 and August 2014 at the Department of Neurology of Chengdu Military General Hospital, China, were analyzed retrospectively. Patients underwent whole-brain CTPI within 1 week of TIA to detect cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and time to peak (TTP) in the ischemic region. Based on cognitive function assessment 4 weeks after TIA, using the Montreal cognitive assessment (MoCA) and mini mental state examination, the patients were divided into control and VCI groups. CTPI parameters and other clinical data were compared between groups, and Spearman's correlation analysis used to identify associations between cognitive scores and CTPI parameters in the VCI group. 50 patients (25 per group; aged 55-72 years) were included. Patient age, gender, smoking status, alcohol consumption, educational level, time from TIA onset to admission, time from TIA onset to CTPI, and prevalence of hypertension, diabetes mellitus, hyperlipidemia, atrial fibrillation and hyperhomocysteinemia did not differ between groups. Both groups showed TTP and MTT prolongation, CBF reduction, but no change in CBV in the ischemic region; these changes were significantly larger in the VCI group (P < 0.05). MTT correlated negatively with MoCA score (r = -0.51, P = 0.009). CTPI could facilitate early diagnosis of VCI in patients with anterior circulation TIA.
Keywords: CT perfusion imaging; Dementia; Transient ischemic attack; Vascular cognitive impairment.