Influencing factors and outcomes of patients with acute ischemic stroke having negative results in diffusion weighted imaging

Abstract

Objective To investigate the influencing factors and outcomes of patients with acute ischemic stroke having negative results in diffusion weighted imaging (DWI). Methods In prospective study, the patients with acute ischemic stroke, admitted to our hospital from October 2016 to January 2018, were selected as research subjects. The demographic and baseline characteristics, imaging data and laboratory examination data were collected. According to the signals of first DWI, the patients were divided into positive DWI group and negative DWI group. The influencing factors of negative results in DWI were clearly defined by univariate and multivariate Logistic regression analyses. The patients from negative DWI group were rechecked for DWI one week after first DWI. All patients were followed up for 90 d, and the outcomes were evaluated by modified Rankin scale (mRS). Results A total of 312 patients with acute ischemic stroke were enrolled finally. The negative rate of DWI was 12.82% (40/312). Multivariate Logistic regression analysis showed that mild stroke (odds ratio [OR]= 2.533, 95% confidence interval[CI]: 1.436-3.984, P=0.038), lacunar infarction (OR=4.668, 95%CI: 2.203-6.543, P=0.005), arteriole occlusion (OR=4.236, 95%CI: 2.448-6.348, P=0.009), brainstem lesion(OR=1.629, 95%CI: 1.035-2.693, P=0.049) and time of onset within hyper-acute period (OR=4.074, 95%CI: 2.683-6.576, P=0.013) were influencing factors for negative results in DWI. The negative rate of DWI in the negative DWI group was reduced to 7.05% (22/312) one week after first DWI. Totally, 302 patients finished the 90 d of follow up; 40 patients were into the negative DWI group, with poor outcome rate of 27.50% (11/40); 262 patients were into the positive DWI group, with poor outcome rate of 30.15% (79/262); the difference of poor outcome rates between the two groups was not statistically significant (P>0.05). Conclusions The negative results in DWI in patients with acute ischemic stroke are closely related to severity of stroke, TOAST etiological types, locations of the lesions, sizes of the lesions and time of onset. Review of DWI can reduce negative rate of DWI. The outcomes of patients with acute ischemic stroke having negative results in DWI are not better than those with positive results in DWI. The patients with acute ischemic stroke having negative results in DWI and having onset within hyper-acute period should not be excluded from intravenous thrombolytic treatment. Key words: Diffusion weighted imaging; Ischemic stroke; Negativity; Influencing factor; Outcome