Comparison of Double Inversion Recovery and FLAIR Sequences in Diagnosing Multiple Sclerosis Infratentorial Plaques

Abstract

Fluid–Attenuated Inversion Recovery (FLAIR) is the most commonly used sequence in routine practice for MS. Recent studies employ alternative sequences such as Double Inversion Recovery (DIR) in addition to conventional MRI techniques. In this study we compared these two sequences for their sensitivity in detecting infratentorial lesions in MS. A total of 24 patients with 3D DIR and 3D FLAIR sequences were included in this study. Plaques were classified according to their localization such as brainstem and cerebellar plaques. The relationship between number of infratentorial plaques and age, gender, MS type, disease duration, average annual number of attacks, cerebellar atrophy existence and EDSS score was also analyzed. DIR sequence detected higher number of lesions compared to FLAIR sequence in brainstem (59 vs 45 plaque in 24 cases) and cerebellum (50 vs 25 plaque in 24 cases). In detecting cerebellar lesions, superiority of DIR sequence compared to FLAIR sequence was statistically significant (p=0.049). Patients with longer disease duration had less cerebellar lesion load in FLAIR sequence at a statistically significant rate. Patients with longer disease duration and higher number of attacks had higher EDSS scores. There was no relationship between brainstem plaques number of cerebellum plaques and EDSS score. Comparing groups with and without cerebellar atrophy, cerebellar atrophy was also more frequent in patients with higher level of cerebellar lesion load in DIR sequence (p=0.028). Our findings suggest that DIR sequence is superior to FLAIR sequence in detecting cerebellar lesions. Cerebellar lesion load detected in DIR sequence was correlated to cerebellar atrophy. For this reason, especially during early period of disease, DIR sequence may be more useful than FLAIR sequence in distinguishing definite MS from clinical isolated syndromes and also for determining atrophy risk.