From the Guidelines
The recommended MRI protocol for diagnosing multiple sclerosis includes brain and spinal cord imaging with specific sequences, as outlined in the most recent guidelines 1. To diagnose multiple sclerosis, a comprehensive MRI protocol should be used, including:
- Sagittal and axial T1-weighted images
- Axial and sagittal T2-weighted images
- Axial FLAIR (fluid-attenuated inversion recovery)
- Contrast-enhanced T1-weighted images with gadolinium The brain scan should cover the entire brain, including the brainstem and cerebellum, while spinal imaging should include the cervical and thoracic regions. Key considerations for the MRI protocol include:
- Slice thickness should be 3mm or less without gaps between slices for optimal lesion detection
- Gadolinium contrast is essential as it helps identify active inflammatory lesions that appear as enhancing areas, indicating breakdown of the blood-brain barrier
- FLAIR sequences are particularly important as they suppress cerebrospinal fluid signal, making periventricular white matter lesions more conspicuous
- Diffusion-weighted imaging may also be included to rule out acute ischemic lesions This protocol is designed to detect the characteristic MS lesions that are disseminated in time and space, which is crucial for diagnosis according to the McDonald criteria, as supported by recent guidelines 1. Follow-up MRIs should use the same protocol for consistent comparison to monitor disease progression and treatment response. It is also important to note that the interpretation of the MRI scans should be performed by trained (neuro)radiologists or clinicians deeply familiar with the features of multiple sclerosis and disorders considered in the differential diagnosis, as emphasized in the guidelines 1.
From the FDA Drug Label
In multiple sclerosis patients, an MRI scan should be obtained prior to initiating therapy with TYSABRI This MRI may be helpful in differentiating subsequent multiple sclerosis symptoms from PML. 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.
The recommended MRI protocol for diagnosing multiple sclerosis includes a gadolinium-enhanced MRI scan of the brain. An MRI scan should be obtained prior to initiating therapy with TYSABRI to help differentiate subsequent multiple sclerosis symptoms from PML. 2
From the Research
MRI Protocol for Diagnosing Multiple Sclerosis
The recommended MRI protocol for diagnosing multiple sclerosis (MS) includes:
- A brain MR imaging with gadolinium for the diagnosis of MS 3
- A spinal cord MR imaging if the brain MR imaging is nondiagnostic or if the presenting symptoms are at the level of the spinal cord 3
- A follow-up brain MR imaging with gadolinium to demonstrate dissemination in time and ongoing clinically silent disease activity while on treatment, to evaluate unexpected clinical worsening, to re-assess the original diagnosis, and as a new baseline before starting or modifying therapy 3
MRI Sequences
The brain MR imaging protocol includes:
- 3D T1-weighted sequences
- 3D T2-FLAIR sequences
- 3D T2-weighted sequences
- Post-single-dose gadolinium-enhanced T1-weighted sequences
- A DWI sequence 3
- The use of three-dimensional (3D) MRI sequences is recommended over two-dimensional (2D) sequences 4
Spinal Cord MRI Protocol
The spinal cord MR imaging protocol includes:
- Sagittal T1-weighted and proton attenuation
- STIR or phase-sensitive inversion recovery
- Axial T2- or T2*-weighted imaging through suspicious lesions
- Postcontrast gadolinium-enhanced T1-weighted imaging in some cases 3
Frequency of MRI
A routine brain MR imaging should be considered every 6 months to 2 years for all patients with relapsing MS 3 The clinical question being addressed should be provided in the requisition for the MR imaging, and the radiology report should be descriptive, with results referenced to previous studies 3
Role of MRI in MS Diagnosis
MRI is the most sensitive method for revealing asymptomatic dissemination of lesions in space and time, and is invaluable for the early diagnosis of MS 5 A standardized MRI protocol for brain and spinal cord is crucial for comparing across studies or between centers 5 MRI evidence plays a supportive role in what is ultimately a clinical diagnosis of MS, in the appropriate clinical situation, and always at the exclusion of alternative diagnoses 5