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[Diffusion-weighted magnetic resonance tomography in diagnosis of encephalitis disseminata]
T Hagen1, G Schweigerer-Schröter, J Wellnitz
1Radiologengemeinschaft Augsburg, Ulmer Strasse 160 A, 86156 Augsburg. hagen@radiologie-augsburg.de
Abstract:
Magnetic resonance (MR) imaging is one of the best methods in diagnosis of multiple sclerosis, particularly in disclosure of active demyelinating lesions. Aim of this study was to compare diffusion weighted imaging and contrast enhancement in the detection of active lesions. A MR study with a contrast enhanced T1-weighted pulse sequence with magnetization transfer presaturation and a diffusion weighted echoplanar pulse sequence (b = 1000 s/mm2) was performed in 17 patients (11 women, 6 men) with multiple sclerosis. 29 of 239 lesions showed an increased signal intensity in diffusion weighted imaging, 24 lesions a contrast enhancement, but only 16 lesions were visible in both pulse sequences. In patients with short clinical symptomatology significant more lesions could be detected with diffusion-weighted pulse sequence in comparison to patients with long standing symptomatology showing more lesions with contrast enhancement. Hence it is likely, that both pulse sequences detect different histopathologic changes. The early detection of demyelinating lesions in diffusion weighted imaging is attributed to the extracellular edema, however the contrast enhancement is caused by a blood brain barrier abnormality. It can be expected that diffusion weighted imaging will have a high impact on imaging of multiple sclerosis not only in therapeutic trials, but also in clinical routine.
Insights
Diffusion weighted imaging detects more early multiple sclerosis lesions than contrast enhancement, indicating distinct pathological changes. This technique shows promise for routine clinical use and therapeutic trials in multiple sclerosis.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Context:
- Multiple Sclerosis (MS) diagnosis relies heavily on Magnetic Resonance (MR) imaging for identifying active demyelinating lesions.
- Differentiating active lesions is crucial for monitoring disease progression and treatment efficacy.
Purpose:
- To compare the efficacy of diffusion weighted imaging (DWI) and contrast enhancement (CE) in detecting active demyelinating lesions in multiple sclerosis patients.
- To investigate if DWI and CE detect different histopathological changes associated with MS.
Summary:
- A MR study compared DWI (b=1000 s/mm2) and contrast-enhanced T1-weighted imaging in 17 MS patients.
- DWI detected more lesions in patients with shorter symptom duration (extracellular edema), while CE detected more in those with longer duration (blood-brain barrier abnormality).
- Only 16 of 239 lesions were detected by both methods, suggesting they visualize distinct pathological processes.
Impact:
- Diffusion weighted imaging shows potential for early detection of demyelinating lesions in multiple sclerosis.
- DWI may significantly impact both clinical routine and therapeutic trials for multiple sclerosis management.
- Findings suggest DWI visualizes early extracellular edema, while CE reflects blood-brain barrier disruption in MS lesions.