History of Hypertension Is Associated With MR Hypoperfusion in Chinese Inpatients With DWI-Negative TIA

Abstract

Objectives: The present study aimed to examine the prevalence of and risk factors for magnetic resonance (MR) perfusion abnormality in a Chinese population with transient ischemic attack (TIA) and normal diffusion-weighted imaging (DWI) findings. Methods: Patients with TIA admitted to our stroke center between January 2015 and October 2017 were recruited to the present study. MRI, including both DWI and perfusion-weighted imaging (PWI), was performed within 7 days of symptom onset. Time to maximum of the residue function (T_max) maps were evaluated using the RAPID software (Ischemaview USA, Version 4.9) to determine hypoperfusion. Multivariate analysis was used to assess perfusion findings, clinical variables, medical history, cardio-metabolic, and the ABCD2 scores (age, blood pressure, clinical features, symptom duration, and diabetes). Results: Fifty-nine patients met the inclusion criteria. The prevalence of MR perfusion T_max ≥ 4 s ≥ 0 ml and ≥ 10 mL were 72.9% (43/59) and 42.4% (25/59), respectively. Multivariate analyses revealed that history of hypertension is an independent factor associated with MR perfusion abnormality (T_max ≥ 4 s ≥ 10 mL) for Chinese patients with TIA (P = 0.033, adjusted OR = 4.11, 95% CI = 1.12-15.11). Proximal artery stenosis (>50%) tended to lead to a larger PW lesion on MRI (p = 0.067, adjusted OR = 3.60, 95% CI = 0.91-14.20). Conclusion: Our results suggest that the prevalence of perfusion abnormality is high as assessed by RAPID using the parametric T_max ≥ 4 s. History of hypertension is a strong predictor of focal perfusion abnormality as calculated by RAPID on T_max map of TIA patients with negative DWI findings.

Keywords: DWI; PWI; hypertension; risk factors; transient ischemic attack.

Figure 1

Typical images of an 84-year old female with a history of hypertension who presented with right upper limb paresis three times within 4 h. It lasted 2 min each time. DWI showed negative findings of strokes (A), but T_max showed focal hypoperfusion areas in the left frontal and parietal lobes (B, green areas).