What imaging modalities are used for Multiple Sclerosis (MS) diagnosis?

From the Guidelines

Magnetic resonance imaging (MRI) is the gold standard imaging technique for diagnosing multiple sclerosis (MS). A standard MS diagnostic MRI protocol should include both brain and spinal cord imaging with T1-weighted sequences (with and without gadolinium contrast), T2-weighted sequences, and fluid-attenuated inversion recovery (FLAIR) sequences, as recommended by the MAGNIMS consensus guidelines 1. These images should be obtained in multiple planes (axial, sagittal, and coronal) to properly visualize lesions. Gadolinium enhancement helps identify active inflammatory lesions, while T2 and FLAIR sequences detect both new and old demyelinating lesions. The 2017 McDonald criteria are used to interpret these findings, looking for evidence of lesions disseminated in space (occurring in multiple areas of the central nervous system) and disseminated in time (showing lesions of different ages) 1.

Some key points to consider when interpreting MRI findings for MS diagnosis include:

• Typical MS lesions appear as hyperintense (bright) areas on T2 and FLAIR sequences, often in periventricular regions, juxtacortical areas, infratentorial structures, and the spinal cord 1.
• The presence of central veins within lesions, as detected by susceptibility-weighted imaging, can help distinguish MS lesions from those caused by other conditions 1.
• Follow-up MRIs are typically performed annually or when new symptoms develop to monitor disease progression and treatment response 1.
• MRI is superior to CT scans for MS diagnosis because it provides better soft tissue contrast and can detect demyelinating lesions that CT scans often miss.

It's essential to note that MRI criteria for MS diagnosis should only be used in the appropriate clinical context, when onset is characterized by clinical manifestations typical of multiple sclerosis 1. In challenging situations, such as low numbers of lesions and confounding comorbidities, both the specific characteristics of each individual lesion and the overall patterns of lesions should be taken into account to support the diagnosis of multiple sclerosis or other conditions 1.

From the FDA Drug Label

In multiple sclerosis patients, an MRI scan should be obtained prior to initiating therapy with TYSABRI Magnetic resonance imaging (MRI) findings may be apparent before clinical signs or symptoms For diagnosis of PML, an evaluation including a gadolinium-enhanced MRI scan of the brain and, when indicated, cerebrospinal fluid analysis for JC viral DNA are recommended. Monitoring with MRI for signs that may be consistent with PML may be useful, and any suspicious findings should lead to further investigation to allow for an early diagnosis of PML, if present

The imaging modality used for Multiple Sclerosis (MS) diagnosis is MRI. Specifically, a gadolinium-enhanced MRI scan of the brain may be used for diagnosis of PML, a potential complication of MS treatment 2.

From the Research

Imaging Modalities for Multiple Sclerosis (MS) Diagnosis

• Magnetic Resonance Imaging (MRI) is the primary imaging modality used for MS diagnosis 3, 4, 5, 6, 7
• MRI plays a crucial role in the international diagnosis criteria (McDonald criteria) and is useful for differential diagnosis 3
• Conventional MRI techniques, such as spin-echo T2-weighted, pre- and post-gadolinium-enhanced spin-echo T1-weighted, and fluid-attenuated inversion-recovery images, are used to assess overt lesions and atrophy in the central nervous system 5, 7
• Advanced MRI techniques, including diffusion-weighted imaging, magnetization transfer imaging, magnetic resonance spectroscopy, and functional MRI, have increased our understanding of the pathogenesis of MS, but their use in clinical practice is still under investigation 5

Role of MRI in MS Diagnosis and Monitoring

• MRI is used for diagnosis, imaging biomarkers, and safety monitoring for patients receiving disease-modifying drugs (DMDs) 3
• MRI assists with early detection of the side effects of DMDs, such as natalizumab-induced progressive multifocal leukoencephalopathy (PML) 3, 4
• MRI is a powerful tool for monitoring the efficacy of DMDs in individual patients and for prognostic evaluation 4, 6
• Standardized imaging protocols and targeted specialized imaging markers are recommended for MS diagnosis and disease monitoring 4