Comparison of 1.5 T and 3.0 T in the detection of inflammatory lesions in patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS)

Purpose: To determine the diagnostic accuracy of 1.5T and 3.0T with regard to the detection of inflammatory lesions in patients with clinically isolated syndromes (CIS) and to investigate the impact of possibly different detection rates on the classification of patients according to the Barkhof MRI criteria.

Methods: 19 Patients with CIS suggestive of MS were examined at a 1.5T and 3.0T system using axial T2 Turbo Spin Echo (T2 TSE) (1.5T: TE 100 ms, TR 3500 ms; 3.0T: TE 100 ms, TR 4100 ms), Fluid-Attenuated Inversion Recovery (FLAIR) (1.5T: TE 110 ms, TR 6000 ms, TI 2000 ms; 3.0T: TE 140 ms, TR 12000 ms, TI 2850 ms) and axial T1 Spin Echo (SE) sequences (1.5T und 3.0T: TE 12 ms, TR 500 ms) prior and after Gadolinium administration. The detection rates of each pulse sequence, stratified by anatomic regions were investigated in a lesion-wise and patient-wise analysis. CSF parameters and EDSS score were assessed in all patients. Classification of the patients regarding to Barkhof MRI criteria was made for both field strengths.

Results: In the lesion-wise analysis FLAIR and T2 TSE at 3.0T detected compared to 1.5T more lesions. In the patient-wise analysis 3.0T detected in 11 patients more lesions than 1.5T. In the remaining 8 patients equivalent numbers of lesions were detected. The subgroup analysis revealed that this finding was statistically significant for the juxtacortical anatomic region. According to the Barkhof MRI criteria the 3.0T examination led to an upgrading of the Barkhof score in 5 patients. One of these patients crossed the diagnostic cut-off point of 3 out of 4 Barkhof criteria. The remaining 14 patients were classified with the same Barkhof score at both field strengths.

Conclusion: High field MRI has a substantial influence on the classification of CIS patients according to the Barkhof MRI criteria.