Conventional and synthetic MRI in multiple sclerosis: a comparative study

Objectives: To compare the assessment of patients with multiple sclerosis (MS) using synthetic and conventional MRI.

Materials and methods: Synthetic and conventional axial images were prospectively acquired for 52 patients with diagnosed MS. Quantitative MRI (qMRI) was used for measuring proton density and relaxation times (T1, T2) and then, based on these parameters, synthetic T1W, T2W and FLAIR images were calculated. Image stacks were reviewed blindly, independently and in random order by two radiologists. The number and location for all lesions were documented and categorised. A combined report of lesion load and presence of contrast-enhancing lesions was compiled for each patient. Agreement was evaluated using kappa statistic.

Results: There was no significant difference in lesion detection using synthetic and conventional MRI in any anatomical region or for any of the three image types. Inter- and intra-observer agreements were mainly higher (p < 0.05) using conventional images but there was no significant difference in any specific region or for any image type. There was no significant difference in the outcome of the combined reports.

Conclusion: Synthetic MR images show potential to be used in the assessment of MS dissemination in space (DIS) despite a slightly lower inter- and intra-observer agreement compared to conventional MRI.

Key points: • Synthetic MR images may potentially be useful in the assessment of MS. • Examination times may be shortened. • Inter- and intra-observer agreement is generally higher using conventional MRI.