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Title Real-world use of non-echoplanar diffusion-weighted magnetic resonance imaging for detection, disease monitoring and clinical decision-making in Graves’ Orbitopathy
Submitted by Claire Feeney
Abstract Number 119
Review Result rapid fire presentation
Purpose

The Clinical Activity Score (CAS) is widely used to grade activity of Graves’ Orbitopathy (GO) and guide treatment decisions but has a number of limitations. Non-echoplanar diffusion-weighted magnetic resonance imaging (non-EPI-DWI) of the extra-ocular muscles (EOMs) may be able to address some of the limitations posed by CAS and other imaging techniques but the correlation with CAS is unknown.

Methods

A retrospective study of 31/88 patients seen in a multidisciplinary GO clinic over a 5 year period who had at least one ophthalmic and endocrine assessment including CAS score and non-EPI-DWI Apparent Diffusion Coefficient (ADC) calculation. Spearman’s rank correlation coefficient was used to determine the relationship between CAS and non-EPI-DWI. A Decision Tree was constructed to evaluate clinical decision-making and Receiver-Operator Curves (ROC) were generated for mild GO and dysthyroid optic neuropathy (DON).

Results

In total, 60 non-EPI-DWI scans (368 EOMs) were evaluated. There was a significant positive correlation between CAS and ADC (rs=0.403 CI 0.312-0.489, P<0.0001). ADC values were significantly higher in the CAS ≥3 group compared to the CAS <3 group, P<0.0001. Our Decision Tree identified a third ‘intermediate’ severity cohort where non-EPI-DWI was particularly useful in guiding clinical decisions. ADC performed well as a diagnostic test in predicting DON (AUC 0.974 95% CI 0.93-1.0).

Conclusion

Non-EPI-DWI correlates well with CAS in our patients and was a useful adjunct to CAS in making clinical decisions especially in patients with ‘intermediate’ severity GO and may also be useful in identifying patients at risk of DON.


Additional Authors
Last name Initials City / Hospital Department
Lingam RK London Northwest University Trust Radiology
Lee V Imperial College Healthcare Trust & Central Middlesex Hospital Ophthalmology
Rahman F Central Middlesex Hospital Ophthalmology
Nagendran S Central Middlesex Hospital Ophthalmology