What matters change on Magnetic Resonance Imaging (MRI) of the brain?

From the Guidelines

White matter changes on brain MRI typically appear as hyperintense (bright) areas on T2-weighted and FLAIR sequences, representing areas of demyelination, gliosis, or small vessel disease. These changes are more sensitively detected by brain MRI compared to head CT, as stated in the guidelines by Alberts et al 1. The guidelines emphasize the importance of brain MRI in detecting small strokes, acute strokes, and many lesions and processes that could produce stroke-like symptoms. Some key points to consider when evaluating white matter changes on brain MRI include:

• The clinical significance of these changes can vary widely, ranging from asymptomatic mild changes to extensive changes correlating with cognitive impairment, gait disturbances, and increased stroke risk.
• Management of white matter changes focuses on controlling vascular risk factors, such as blood pressure management, diabetes control, smoking cessation, and maintaining healthy cholesterol levels, as supported by the guidelines 1.
• The progression of white matter changes can be monitored with follow-up MRI scans, typically at intervals determined by the clinical context and severity of findings. The guidelines recommend that brain MRI should be available at a primary stroke center (PSC) for admitted patients who might benefit from such testing, and that imaging of the extracranial and intracranial vasculature, such as MR angiography (MRA) and CT angiography (CTA), should also be available at a PSC 1.

From the FDA Drug Label

MRI Results Gadolinium (Gd)-enhanced and T2-weighted magnetic resonance imaging (MRI) scans of the brain were obtained in most patients at baseline and at the end of 1 and 2 years of treatment. Secondary outcomes included Gd-enhanced lesion number and volume, and T2-weighted lesion volume Gd-enhancing lesions seen on brain MRI scans represent areas of breakdown of the blood brain barrier thought to be secondary to inflammation. AVONEX-treated patients demonstrated significantly lower Gd-enhanced lesion number after 1 and 2 years of treatment than placebo-treated patients (p ≤ 0. 05; see Table 3). The volume of Gd-enhanced lesions showed similar treatment effects in the AVONEX and placebo groups (p ≤ 0.03). Percentage change in T2-weighted lesion volume from study entry to Year 1 was significantly lower in AVONEX-treated than placebo-treated patients (p = 0. 02). A significant difference in T2-weighted lesion volume change was not seen between study entry and Year 2 in the AVONEX and placebo groups.

The matter change on MRI brain is related to the Gd-enhanced lesion number and T2-weighted lesion volume.

• Gd-enhanced lesion number was significantly lower in AVONEX-treated patients than in placebo-treated patients after 1 and 2 years of treatment.
• T2-weighted lesion volume change from study entry to Year 1 was significantly lower in AVONEX-treated patients than in placebo-treated patients. Key points:
• AVONEX treatment reduces the number of Gd-enhanced lesions.
• AVONEX treatment reduces the T2-weighted lesion volume change from study entry to Year 1. 2

From the Research

Changes in Matter on MRI Brain

• Multiple sclerosis (MS) lesions can change on MRI brain scans after treatment with interferon beta, with a reduction in contrast-enhancing lesions observed in some studies 3, 4.
• The appearance of new lesions on T2-weighted MRI scans after 1 year of interferon beta treatment can predict a poor response to therapy 5.
• Incidental findings on brain MRI, such as asymptomatic brain infarct, age-related white matter changes, and microhemorrhages, can also be observed in adults 6.
• Increases in soluble VCAM-1 have been correlated with a decrease in MRI lesions in MS patients treated with interferon beta-1b, suggesting a potential mechanism of action for the treatment 4.
• Beta interferon treatment has been associated with a lower mortality risk among people with relapsing-onset MS, with increased survival observed in those with more than 3 years of exposure to the treatment 7.

Types of Changes

• Reduction in contrast-enhancing lesions
• Appearance of new lesions on T2-weighted MRI scans
• Changes in soluble adhesion molecules, such as VCAM-1
• Incidental findings, such as asymptomatic brain infarct and age-related white matter changes

Clinical Implications

• Monitoring of MS lesions on MRI brain scans can inform treatment decisions and predict response to therapy 3, 5.
• Management of incidental findings on brain MRI can pose a challenge for referring physicians, highlighting the need for appropriate guidelines and recommendations 6.
• Beta interferon treatment may have a positive impact on survival in people with relapsing-onset MS, although further research is needed to confirm this association 7.