Risk Factors That Affect Diffusion-Weighted Imaging Results on Patients with Acute Ischemic Stroke: A Retrospective Analysis

Abstract

Background: Diffusion-weighted imaging (DWI) may not always provide positive results for acute ischemic stroke diagnosis (AIS). In the present study, we aim to identify risk factors that affect the frequency of inconsistent DWI results in patients with AIS. Methods: A total of 212 patients diagnosed with AIS underwent DWI at the time of hospital admission and 24 hours after AIS was diagnosed. According to the outcome of the two DWI results, patients were classfied into the inconsistent group (negative for initial scan, but positive for second scan) and the consistent group (negative or positive for both scans). A number of parameters were compared between the two patient groups, including demographic characteristics, disease history, imaging time, cause of stroke and NIHSS score at admission. Univariate and multivariate analysis were employed to predict the independent risk factors for inconsistent DWI results. Results: We found that prior stroke experience, time of initial DWI scan prior to the diagnosis of AIS (also referred as DWI latency) and time between the first and second DWI were all significantly different between the two patient groups. All 3 factors were also identified as independent risk factors for the inconsistent DWI results. In addition, probability of DWI latency shows an increasing trend in a time-dependent manner up to 3 hours. Conclusion: Our data indicate that DWI should be performed within three hours since hospital admission and repeated within 24 hours after AIS is diagnosed, especially for the patients that showed negative results in the initial scan.