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Updated: Apr 27, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Validity of negative high-resolution diffusion-weighted imaging in transient acute cerebrovascular events
Benjamin Hotter1, Anna Kufner, Uwe Malzahn
1Department of Neurology, Charité University Hospital Berlin, Berlin, Germany. benjamin.hotter@charite.de
Background And Purpose:
A significant amount of strokes are reported to be diffusion-weighted imaging (DWI) negative in acute imaging. We attempted to quantify the rate of false-negative high-resolution (hr) DWI and to identify a valid screening tool to guide follow-up MRI to diagnose infarction initially not visible on hrDWI.
Methods:
An a priori-defined post hoc analysis of a prospective 3T MRI cohort of acute cerebrovascular events imaged within 24 hours of ictus. Basic demographics, risk factors, National Institute of Health Stroke Scale, and imaging parameters were recorded.
Results:
Of 151 patients with negative acute hrDWI, 63 received follow-up scans depicting infarction in 7 cases (11.1%). Persistence of clinical symptoms as established by National Institute of Health Stroke Scale on the following day was strongly associated with infarction on follow-up MRI (odds ratios, 17.5; 95% confidence interval, 2.83-108.12). Negative predictive value of follow-up National Institute of Health Stroke Scale was 0.96.
Conclusions:
Infarcts are frequently invisible on initial hrDWI, but we may well trust in negative hrDWI in completely transient cerebrovascular events.
Insights
Many strokes initially appear negative on high-resolution diffusion-weighted imaging (hrDWI). Persistent National Institute of Health Stroke Scale symptoms strongly predict infarction on follow-up MRI, suggesting its utility in diagnosing stroke.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- A significant proportion of acute strokes are initially negative on diffusion-weighted imaging (DWI).
- High-resolution DWI (hrDWI) may miss early ischemic changes.
- Accurate diagnosis of early stroke is crucial for timely intervention.
Purpose of the Study:
- To quantify the rate of false-negative findings on acute hrDWI.
- To identify a reliable screening tool for guiding follow-up MRI in suspected stroke cases.
- To improve the diagnostic yield of MRI in acute ischemic events.
Main Methods:
- Post hoc analysis of a prospective 3T MRI cohort of acute cerebrovascular events within 24 hours of ictus.
- Inclusion of patient demographics, risk factors, and National Institute of Health Stroke Scale (NIHSS) scores.
- Evaluation of initial hrDWI and follow-up MRI scans for evidence of infarction.
Main Results:
- Among 151 patients with negative acute hrDWI, 7 (11.1%) showed infarction on follow-up MRI.
- Persistent NIHSS symptoms on day 2 strongly correlated with infarction on follow-up MRI (OR, 17.5).
- The negative predictive value of a follow-up NIHSS was 0.96.
Conclusions:
- Acute infarcts are often undetectable on initial hrDWI.
- Negative hrDWI can be trusted in cases of completely transient cerebrovascular events.
- NIHSS scores are valuable in identifying patients requiring further MRI investigation for stroke.
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