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Updated: May 22, 2026
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
Reduced diffusion in a subset of acute MS lesions: a serial multiparametric MRI study
1Department of Neurology, UniversitätsMedizin Mannheim, University of Heidelberg, Mannheim, Germany.
Background And Purpose:
MRI studies have focused on newly developing MS lesions to characterize the early pathology of the disease. DWI is highly sensitive to acute and chronic tissue changes in MS. We characterized the development of acute MS lesions by using DWI in a multiparametric MRI protocol.
Materials And Methods:
Seventy-two consecutive patients presenting with a new symptom with definite MS or a CIS suggestive of central nervous system demyelination were screened with MRI. Patients who showed an acute MRI lesion with a reduction of ADC were studied with serial MRI for up to 4 months after presentation.
Results:
Ten of 72 screened patients who showed a lesion with a reduced ADC were each examined 4-7 times, resulting in 52 examinations in total. We identified a characteristic sequence of signal-intensity changes: 1) days 0-7: slight T2 hyperintensity and prominent ADC reduction (maximum, -66%), faint or no enhancement on postcontrast T1-weighted images; 2) days 7-10: prominent T2 hyperintensity and contrast enhancement, ADC normalization/pseudonormalization; 3) up to 4 weeks: elevated ADC values, prominent enhancement on postcontrast images; 4) after 4 weeks: partial reversibility of T2 hyperintensity, ADC elevation, and resolution of contrast enhancement.
Conclusions:
In a subgroup of patients with MS presenting soon after new symptom onset, a transient reduction of the ADC delineated a short and very early phase of MS lesion evolution. Subsequent pseudonormalization of the ADC occurred along with signs of the development of vasogenic edema.
Insights
Diffusion-weighted imaging (DWI) reveals a transient reduction in apparent diffusion coefficient (ADC) during the early evolution of acute multiple sclerosis (MS) lesions. This early phase is followed by ADC normalization, indicating vasogenic edema development.
Area of Science:
- Neuroimaging
- Neurology
- Radiology
Background:
- Multiple sclerosis (MS) lesion characterization often focuses on early disease pathology.
- Diffusion-weighted imaging (DWI) is sensitive to acute and chronic tissue changes in MS.
Purpose of the Study:
- To characterize the development of acute MS lesions using DWI within a multiparametric MRI protocol.
- To investigate early pathological changes in MS lesions.
Main Methods:
- Seventy-two patients with suspected central nervous system demyelination underwent MRI screening.
- Patients with acute lesions showing reduced apparent diffusion coefficient (ADC) were studied with serial MRI for up to 4 months.
Main Results:
- Ten patients with reduced ADC lesions were examined 4-7 times (52 total examinations).
- A characteristic sequence of signal changes was identified: early ADC reduction, followed by normalization/pseudonormalization with contrast enhancement, and later ADC elevation.
Conclusions:
- Transient ADC reduction in early MS lesions delineates a very early phase of evolution.
- Subsequent ADC pseudonormalization correlates with vasogenic edema development in MS lesions.
