What should be routinely assessed in the follow-up MRI of a multiple sclerosis (MS) patient with a stable magnetic resonance imaging (MRI) showing a stable burden of intracranial and cervical spine lesions?

Routine MRI Assessment in MS Patients with Stable Lesion Burden

In follow-up MRI assessment of MS patients with stable lesion burden, you should systematically evaluate for new or enlarging T2 lesions, contrast-enhancing lesions, and changes in lesion characteristics while maintaining standardized acquisition protocols across sequential scans to ensure accurate comparison.

Brain MRI Assessment Components

Mandatory Sequences and Evaluation

• T2-weighted/FLAIR sequences: Assess for:

  • New or enlarging T2 hyperintense lesions (≥3mm) 1
  • Changes in existing lesion morphology (round to ovoid shape)
  • Lesion distribution in characteristic locations:
    • Periventricular (abutting lateral ventricles)
    • Juxtacortical (adjacent to cortex)
    • Infratentorial (brainstem/cerebellum)
    • Corpus callosum 1, 2

• T1-weighted sequences with gadolinium: Evaluate for:

  • Contrast-enhancing lesions (indicating active inflammation)
  • Pattern of enhancement (nodular vs. ring)
  • Persistence of T1 hypointense "black holes" (marker of neurodegeneration) 1, 2

Technical Considerations

• Use identical MRI system and imaging protocol as baseline scan
• Maintain consistent slice positioning between scans
• Allow minimum 5-minute delay after contrast injection before T1 acquisition 1
• Use single dose (0.1 mmol/kg) of gadolinium-based contrast 1

Cervical Spine MRI Assessment Components

Mandatory Sequences and Evaluation

• Sagittal dual-echo (PD and T2-weighted) sequences: Assess for:

  • New or enlarging focal lesions (cigar-shaped on sagittal images)
  • Lesion characteristics (clearly demarcated borders, <2 vertebral segments)
  • Lesion location (peripheral spinal cord, lateral/dorsal columns) 1

• Contrast-enhanced T1-weighted sequences (if T2 lesions present): Evaluate for:

  • Nodular or ring enhancement
  • Spinal cord swelling 1

Red Flags to Monitor

• Longitudinally extensive lesions (≥3 vertebral segments)
• Prominent central gray matter involvement
• Excessive spinal cord swelling
• Leptomeningeal or nerve root involvement 1

Standardization and Comparison Approach

1. Use consistent protocols: Maintain same field strength, sequences, and spatial resolution across serial scans 1
2. Direct comparison: Place baseline and follow-up images side-by-side for assessment 3
3. Systematic evaluation: Assess each anatomical region in the same order each time
4. Document findings: Record location, size, and characteristics of all lesions 3

Clinical Correlation and Monitoring Considerations

• Asymptomatic cervical spine lesions occur in 4.8-12.1% of routine surveillance scans 4
• Higher lesion volumes correlate with increased risk of relapses and new MRI lesions 5
• Lesions in lateral funiculi and central cord area correlate significantly with disability (EDSS score) 6
• Black/African American patients may benefit from more frequent cervical spine imaging due to higher risk of asymptomatic lesions 4

Common Pitfalls to Avoid

1. Inconsistent acquisition parameters: Changes in scanner, field strength, or sequence parameters can create artificial differences between scans 3
2. Misinterpreting artifacts: Flow-related artifacts in spinal cord can mimic lesions 1
3. Overlooking small lesions: Lesions should be visible on at least two consecutive slices to exclude artifacts 1
4. Inadequate training: Formal training significantly improves reproducibility of lesion assessment (reducing variability from 10-16% to 5.6-7.3%) 7
5. Overinterpreting diffuse abnormalities: Only focal lesions with clearly demarcated borders should be considered MS-related 1

By following this systematic approach to MRI assessment in MS patients with stable lesion burden, you can accurately monitor disease activity and detect subtle changes that may warrant treatment adjustments, even in clinically stable patients.