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Published on: September 16, 2017
Quantitative Analysis of Diffusion-Restricted Lesions in a Differential Diagnosis of Status Epilepticus and Acute
Lukas Machegger1, Pilar Bosque Varela2, Giorgi Kuchukhidze2,3
1Department of Neuroradiology, Christian Doppler University Hospital, Paracelsus Medical University, Salzburg, Austria.
Background And Purpose:
Distinction between acute ischemic stroke (AIS) and status epilepticus (SE) on MRI can be challenging as restricted diffusion may occur in both conditions. In this study, we aimed to test a tool, which could help in differentiating AIS from SE when restricted diffusion was present on MRI.
Materials And Methods:
In diffusion weighted imaging (DWI) with a b-value of 1,000 and apparent diffusion coefficient (ADC) maps, we compared the ratios of intensities of gray values of diffusion-restricted lesions to the healthy mirror side in patients with AIS and SE. Patients were recruited prospectively between February 2019 and October 2021. All patients underwent MRI and EEG within the first 48 h of symptom onset.
Results:
We identified 26 patients with SE and 164 patients with AIS. All patients had diffusion-restricted lesions with a hyperintensity in DWI and ADC signal decrease. Diffusion restriction was significantly more intense in patients with AIS as compared to patients with SE. The median ratios of intensities of gray values of diffusion-restricted lesions to the healthy mirror side for DWI were 1.42 (interquartile range [IQR] 1.32-1.47) in SE and 1.67 (IQR 1.49-1.90) in AIS (p < 0.001). ADC decrease was more significant in AIS as compared to SE with median ratios of 0.80 (IQR 0.72-0.89) vs. 0.61 (IQR 0.50-0.71), respectively (p < 0.001). A cutoff value for ratios of DWI signal was 1.495 with a sensitivity of 75% and a specificity of 85%. Values lower than 1.495 were more likely to be associated with SE and higher values were with AIS. A cutoff value for ADC ratios was 0.735 with a sensitivity of 73% and a specificity of 84%. Values lower than 0.735 were more likely to be associated with AIS and higher values were with SE.
Conclusion:
Diffusion restriction and ADC decrease were significantly more intense in patients with AIS as compared to SE. Therefore, quantitative analysis of diffusion restriction may be a helpful tool for differentiating between AIS and SE when restricted diffusion is present on MRI.
Insights
Quantitative MRI analysis of diffusion restriction can differentiate acute ischemic stroke (AIS) from status epilepticus (SE). Higher diffusion restriction intensity suggests AIS, while lower intensity indicates SE, aiding in diagnosis when MRI findings are similar.
Area of Science:
- Neuroradiology
- Neurology
- Medical Imaging
Background:
- Distinguishing acute ischemic stroke (AIS) from status epilepticus (SE) on MRI is challenging due to overlapping restricted diffusion patterns.
- Developing reliable methods to differentiate these conditions is crucial for timely and appropriate treatment.
Purpose of the Study:
- To evaluate the utility of quantitative diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) map analysis in differentiating AIS from SE.
- To assess if the intensity of diffusion restriction can serve as a reliable marker for distinguishing between AIS and SE.
Main Methods:
- Prospective comparison of DWI and ADC map intensity ratios between lesions and healthy tissue in patients with AIS and SE.
- Inclusion of patients who underwent MRI and EEG within 48 hours of symptom onset.
- Analysis involved 164 AIS patients and 26 SE patients.
Main Results:
- Diffusion restriction was significantly more intense in AIS compared to SE (DWI ratio: 1.67 vs. 1.42, p < 0.001; ADC ratio: 0.80 vs. 0.61, p < 0.001).
- A DWI signal ratio cutoff of 1.495 achieved 75% sensitivity and 85% specificity.
- An ADC ratio cutoff of 0.735 achieved 73% sensitivity and 84% specificity.
Conclusions:
- Quantitative analysis of diffusion restriction intensity on MRI is a valuable tool for differentiating AIS from SE.
- More intense diffusion restriction is indicative of AIS, whereas less intense restriction suggests SE.
- This quantitative approach can improve diagnostic accuracy in cases with ambiguous MRI findings.
