Double inversion recovery brain imaging at 3T: diagnostic value in the detection of multiple sclerosis lesions

Abstract

Background and purpose: To prospectively determine the sensitivity in the detection of multiple sclerosis (MS) lesions by using double inversion recovery (DIR), fluid-attenuated inversion recovery (FLAIR), and T2-weighted turbo spin-echo (T2 TSE) MR imaging at 3T.

Methods: Seventeen patients presenting with a clinically isolated syndrome (CIS) suggestive of MS, 9 patients with definite MS, and 6 healthy control subjects were included. Imaging was performed on a 3T MR system using DIR, FLAIR, and T2 TSE sequences. Lesions were counted and classified according to 5 anatomic regions: infratentorial, periventricular, deep white matter, juxtacortical, and mixed white matter-gray matter. The sensitivity at DIR was compared with the corresponding sensitivity at FLAIR and T2 TSE sequence. The contrast between lesions and normal-appearing gray matter, normal-appearing white matter, and CSF was determined for all sequences.

Results: Because of higher lesion-white matter contrast, the DIR showed a higher number of lesions compared with the FLAIR (7% gain, P = 0.04) and the T2 TSE (15% gain, P = 0.01). The higher sensitivity was also significant for the infratentorial region compared with the FLAIR (56% gain, P = 0.02) and the T2 TSE (44% gain, P = 0.02). Compared with the FLAIR, no significant changes of the lesion load measurements were observed in the supratentorial brain: slightly higher numbers of periventricular and mixed gray matter-white matter lesions on the DIR were counterbalanced by a slightly reduced sensitivity regarding juxtacortical lesions.

Conclusion: DIR brain imaging at 3T provides the highest sensitivity in the detection of MS lesions especially in the infratentorial region.

Fig 1.

Transverse T2-weighted TSE, FLAIR, and DIR image examples documenting the higher sensitivity of DIR in the detection of inflammatory brain lesion in the infratentorial brain. Top row (A–C), A 36-year-old woman presenting with a polysymptomatic CIS. A sharp delineated inflammatory lesion in the left pedunculus cerebelli (arrow) can be clearly identified on the DIR image but not on the corresponding sections of the T2 TSE and FLAIR sequences. Bottom row (D–F), A 23-year-old man presenting with optic neuritis of the left eye. Compared with the T2 TSE and FLAIR images, more lesions in both hemispheres of the cerebellum (arrows) can be identified on the DIR image. Moreover, those lesions identified on all 3 sequences were better delineated on DIR compared with the corresponding T2 TSE and FLAIR images.

Fig 2.

Transverse FLAIR (bottom row) and DIR (top row) sections of the supratentorial brain. The inflammatory lesions have a more sharp delineated appearance on the DIR compared with the corresponding FLAIR images. Despite a minor contrast between lesions and the normal-appearing gray matter, DIR showed a high sensitivity in the detection of juxtacortical and mixed white matter-gray matter lesions (arrows). A differentiation between juxtacortical and mixed white matter-gray matter lesions is much easier on the DIR than on the FLAIR images. Regarding the periventricular white matter, the lesions are easier to identify on the DIR compared with the FLAIR images (open arrows).

Fig 3.

Image examples of the improved detection of mixed white matter-gray matter lesions on the DIR pulse sequence. These images were obtained from a 40-year-old woman with a relapsing-remitting course of MS (disease duration, 165 months; EDSS, 6) presenting with a high lesion load on the MR imaging, including mixed white matter-gray matter lesions. Top row, an example of different classifications of a lesion using different pulse sequences. A lesion (arrow) was prospectively classified as a juxtacortical lesion on the T2 TSE and FLAIR images. Because of the better delineation of the white and gray matter on the DIR image, this lesion had to reclassified into a mixed white matter-gray matter lesion. Bottom row, an example of the higher conspicuity of a cortical lesion (arrow) on the DIR image that was not prospectively identified on the corresponding T2 TSE and FLAIR images. Another lesion (open arrow) could be easily identified and categorized on the DIR image as a pure juxtacortical lesion without touching the cortex.