Diagnostic utility of 3D DIR MRI in the estimation of MS lesions overall load with special emphasis on cortical subtypes.

Background: A number of magnetic resonance imaging studies have shown that a significant proportion of multiple sclerosis (MS) lesions are located in the cerebral cortex and correlate with the patient's disability level. Double inversion recovery (DIR) has a higher sensitivity to detect cortical lesions and their different types. The aim of our study was to assess the superiority of 3D DIR as compared to FLAIR in detecting the different cortical subtypes and to enhance its role as a test for the clinical disability of the patient. Results: The current study included 82 MS patients (60 female and 22 male with mean age of 34.5 ± 8.2 years); 59 cases having relapsing–remitting MS, 5 having secondary progressive MS, and 4 having primary progressive MS, as well as eight clinically isolated syndrome cases, and six radiologically isolated syndrome cases. DIR was superior to FLAIR in MS plaque number detection of cortical plaque-types 1, 2, 3 and 4 with a p value < 0.001. DIR was superior to FLAIR for detection of overall cortical types, juxtacortical and juxtacortical extended MS plaques with p = < 0.001, 0.010 and < 0.001, respectively. DIR was significantly better than FLAIR for MS plaque number detection in the periventricular white matter, subcortical white matter, infratentorial region and the overall MS plaques burden with a p < 0.001, 0.038, < 0.001, < 0.001, respectively. No significant difference was noted between both sequences for plaques number detection in deep white matter and deep gray matter. A significant correlation between MS disease duration, number of attacks and EDSS and the overall cortical MS plaques types and the overall MS plaque burden. Conclusion: 3D DIR is a reliable tool and provides superior delineation in detecting cortical subtypes. In addition, DIR is of value in assessing the degree of clinical and cognitive impairment of MS affected patients. [ABSTRACT FROM AUTHOR]