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Published on: October 7, 2021
Low interrater reliability of brachial plexus MRI in chronic inflammatory neuropathies
Marieke H J van Rosmalen1, H Stephan Goedee1, Anouk van der Gijp2
1Department of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, Utrecht University, The Netherlands.
Introduction:
Magnetic resonance imaging of the brachial plexus shows nerve thickening in approximately half of the patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). The reliability of qualitative evaluation of brachial plexus MRI has not been studied previously.
Methods:
We performed an interrater study in a retrospective cohort of 19 patients with CIDP, 17 patients with MMN, and 14 controls. The objective was to assess interrater variability between radiologists by using a predefined scoring system that allowed the distinction of no, possible, or definite nerve thickening.
Results:
Raters agreed in 26 of 50 (52%) brachial plexus images; κ-coefficient was 0.30 (SE 0.08, 95% confidence interval 0.14-0.46, P < .0005).
Discussion:
Our results provide evidence that interrater reliability of qualitative evaluation of brachial plexus MRI is low. Objective criteria for abnormality are required to optimize the diagnostic value of MRI for inflammatory neuropathies.
Insights
Brachial plexus MRI for chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) has low interrater reliability. Standardized criteria are needed to improve diagnostic accuracy for these inflammatory neuropathies.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Nerve thickening on brachial plexus MRI is observed in chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN).
- The diagnostic reliability of qualitative brachial plexus MRI evaluations has not been previously assessed.
Purpose of the Study:
- To evaluate the interrater reliability of qualitative brachial plexus MRI assessments.
- To determine the variability between radiologists in diagnosing nerve thickening in inflammatory neuropathies.
Main Methods:
- An interrater study was conducted on a retrospective cohort.
- 19 patients with CIDP, 17 with MMN, and 14 controls were included.
- A scoring system for nerve thickening (none, possible, definite) was used.
Main Results:
- Radiologists achieved agreement on 52% of brachial plexus images.
- The interrater reliability, measured by the κ-coefficient, was 0.30, indicating low agreement.
- Statistical analysis confirmed the low reliability (P < .0005).
Conclusions:
- Qualitative evaluation of brachial plexus MRI demonstrates low interrater reliability.
- Objective criteria are essential for enhancing the diagnostic utility of MRI in inflammatory neuropathies.
- Further research is needed to establish standardized MRI interpretation guidelines.
