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Use of high b value diffusion-weighted magnetic resonance imaging in acute encephalopathy/encephalitis during
Yoshiko Tsubouchi1, Shinji Itamura1, Yoshiaki Saito1
1Division of Child Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, Japan.
Insights
High b value diffusion-weighted imaging (DWI) at b=3000 is superior for detecting brain lesions in childhood acute febrile encephalopathy/encephalitis. This advanced DWI technique improves diagnostic accuracy for these critical neurological conditions.
Area of Science:
- Pediatric Neurology
- Neuroradiology
- Medical Imaging
Background:
- Acute febrile encephalopathy and encephalitis are serious neurological conditions in children.
- Accurate and early diagnosis is crucial for effective management and improved outcomes.
- Diffusion-weighted imaging (DWI) is a key MRI technique for evaluating brain abnormalities.
Purpose of the Study:
- To evaluate the utility of high b-value DWI (b=3000 s/mm²) compared to standard b-value DWI (b=1000 s/mm²) in diagnosing childhood acute febrile encephalopathy/encephalitis.
- To assess the diagnostic performance of DWI in differentiating various subtypes of encephalopathy/encephalitis.
Main Methods:
- Twenty-two children with acute febrile encephalopathy/encephalitis underwent DWI (b=1000 and b=3000 s/mm²) and apparent diffusion coefficient (ADC) mapping.
- Lesion conspicuity on b=3000 DWI was compared to b=1000 DWI via visual inspection.
- Quantitative analysis included ADC values and signal intensity (SI) ratios.
Main Results:
- High-intensity lesions were either exclusively visible or more clearly identified on b=3000 DWI compared to b=1000 DWI in most cases (17/22).
- The signal intensity (SI) ratio was significantly higher on b=3000 DWI across all subjects and in specific subgroups (AESD, MERS).
- Lower mean ADC values were observed in acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and clinically mild encephalopathy/encephalitis with a reversible splenial lesion (MERS) compared to herpes simplex virus encephalitis (HSE).
Conclusions:
- b=3000 DWI demonstrates superior sensitivity in detecting abnormal lesions associated with acute encephalopathy/encephalitis in children.
- High b-value DWI enhances the diagnostic capability for these pediatric neurological emergencies.
- Further research may refine the role of advanced DWI techniques in clinical practice.
Aim:
To determine the use of high b value diffusion-weighted imaging (DWI) in the diagnosis and assessment of acute febrile encephalopathy/encephalitis in childhood.
Subjects And Methods:
We enrolled 22 children, for whom we examined DWI with b=1000s/mm2, DWI with b=3000s/mm2, and apparent diffusion coefficient (ADC) map with b=1000 during the acute phase of febrile encephalopathy/encephalitis. Clinical diagnoses included acute encephalopathy with biphasic seizures and late reduced diffusion (AESD; n=6), clinically mild encephalopathy/encephalitis with a reversible splenial lesion (MERS; n=6), and herpes simplex virus encephalitis (HSE; n=3), unclassified acute encephalopathy/acute encephalitis (n=2); acute encephalitis with refractory, repetitive partial seizures (AERRPS; n=1); other encephalopathy (n=1); infarction (n=1); head injury (n=1); or mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (n=1). The diagnostic quality of brain lesions was compared between b=1000 and b=3000 DWI images by visual inspection. In addition, we attempted a quantitative assessment using apparent diffusion coefficient (ADC) value and an index of signal intensity (SI) ratio, defined as the mean SI at the affected lesion divided by the mean SI at the pons.
Results:
High intensity lesions were either visible only on b=3000 DWI (n=5; 2 AESD, 1 MERS, 1 HSE, and 1 unclassifiable encephalopathy) or more effectively identified on b=3000 DWI than on b=1000 DWI (n=17). The outcome of the former five subjects was favorable, without motor or intellectual sequelae. The mean SI ratio of b=3000 was significantly greater than that of b=1000 in AESD and MERS subgroups as well as in all 22 subjects. Mean ADC values were lower in the AESD and MERS than that in the HSE subgroups.
Conclusion:
We concluded that b=3000 DWI was superior to b=1000 DWI in detecting abnormal lesions in acute encephalopathy/encephalitis during childhood.
