What are the guidelines for interpreting an MRI (Magnetic Resonance Imaging) reading?

Guidelines for Interpreting an MRI Reading

MRI interpretation requires a structured approach with standardized reporting to ensure accurate diagnosis and effective communication between radiologists and referring clinicians.

MRI Report Structure

A comprehensive MRI report should include the following key components 1:

1. MRI Technique

• Brief description of anatomical area covered (brain, spinal cord, optic nerve, etc.)
• Field strength used (minimum 1.5T recommended) 1
• Slice thickness (3mm with no gap between slices is optimal) 1
• Type and dose of contrast agent if used
• Sequences performed (T1, T2, FLAIR, DWI, etc.)

2. Findings

The findings section should include 1:

• Systematic description of all imaging findings using standardized terminology
• Lesion characteristics:
  • Number and topography
  • Size and shape
  • Signal characteristics across different sequences
  • Enhancement patterns if contrast was used
  • Qualitative assessment of lesion load
  • Brain atrophy assessment (if applicable)

3. Conclusion

The conclusion should 1:

• Provide a clear radiological interpretation related to the clinical problem
• Identify typical or atypical findings
• Offer differential diagnosis when appropriate
• Indicate evidence of disease activity or progression (in follow-up scans)
• Note any incidental or unexpected findings, classified as clinically relevant or irrelevant

Specific Guidelines by Anatomical Region

Brain MRI

• T2-FLAIR is optimal for lesion detection in the brain 1
• Confirm lesions on multiple planes to avoid artifacts 1
• For multiple sclerosis evaluation, look for lesions in characteristic regions (periventricular, juxtacortical, infratentorial) 1
• White matter lesions should be carefully evaluated, especially in patients >50 years or with vascular risk factors 1

Spinal Cord MRI

• T2-weighted sequences are preferred over T2-FLAIR for spinal cord imaging 1
• Sagittal STIR can improve contrast-to-noise ratio but is susceptible to flow-related artifacts 1
• Additional axial T2-weighted images should be performed to verify changes seen in the sagittal plane 1

Oncological MRI

For cancer screening or evaluation, the ONCO-RADS system provides a structured approach 1:

• Categorize findings from 1-5 based on likelihood of malignancy
• ONCO-RADS 1: Normal finding
• ONCO-RADS 2: Benign finding highly likely
• ONCO-RADS 3: Benign finding likely
• ONCO-RADS 4: Malignant finding likely
• ONCO-RADS 5: Malignant finding highly likely

Competency Requirements

Proper MRI interpretation requires 2:

• Understanding of MRI physics and scanning principles
• Knowledge of contrast enhancement techniques
• Familiarity with multiple pulse sequences (T1, T2, STIR, DWI)
• Recognition of normal anatomy, variants, and pathological conditions
• Ability to identify false-positive and false-negative findings

Follow-up MRI Guidelines

For monitoring disease progression (e.g., in multiple sclerosis) 1:

• Contrast-enhanced T1-weighted and T2-weighted scans to reveal inflammation and new/enlarging lesions
• MRI subtraction techniques to facilitate detection of new lesions across serial scans
• Follow-up scans at least annually, or more frequently (every 3-4 months) for patients requiring enhanced pharmacovigilance

Common Pitfalls to Avoid

1. Inadequate technique: Ensure appropriate sequences for the clinical question are performed 1
2. Misinterpretation of artifacts: Confirm findings on multiple sequences and planes 1
3. Incomplete evaluation: Systematically review all anatomical regions included in the scan 1
4. Inconsistent terminology: Use standardized terminology for clear communication 1
5. Failure to correlate with clinical information: Always interpret findings in the clinical context 1

Structured Reporting Recommendations

Structured reporting improves communication and clinical decision-making 1:

• Present information in a standardized format
• Include relevant clinical data
• Use clear, consistent terminology
• Integrate technical parameters
• Provide definitive conclusions with appropriate recommendations for follow-up

By following these guidelines, radiologists and clinicians can ensure accurate interpretation of MRI studies, leading to improved patient care and outcomes.