Although not designed as a formal interobserver study, the current study suggests that comparing available literature data on cortical lesions may be problematic, and increased consistency in acquisition protocols may improve scoring agreement. Sensitivity and specificity of the proposed recommendations should now be studied in a more formal, prospective, multicenter setting using similar DIR protocols.

Cortical lesions increase significantly over a 3-year time period, are most frequent in SP patients, and are associated with cognitive impairment.

To describe signal and contrast properties of an isotropic, single-slab 3D dataset [double inversion-recovery (DIR), fluid-attenuated inversion recovery (FLAIR), T2, and T1-weighted magnetization prepared rapid acquisition gradient-echo (MPRAGE)] and to evaluate its performance in detecting multiple sclerosis (MS) brain lesions compared to 2D T2-weighted spin-echo (T2SE). All single-slab 3D sequences and 2D-T2SE were acquired in 16 MS patients and 9 age-matched healthy controls. Lesions were scored independently by two raters and characterized anatomically. Two-tailed Bonferroni-corrected Student's t-tests were used to detect differences in lesion detection between the various sequences per anatomical area after logtransformation. In general, signal and contrast properties of the 3D sequences enabled improved detection of MS brain lesions compared to 2D-T2SE. Specifically, 3D-DIR showed the highest detection of intracortical and mixed WM-GM lesions, whereas 3D-FLAIR showed the highest total number of WM lesions. Both 3D-DIR and 3D-FLAIR showed the highest number of infratentorial lesions. 3D-T2 and 3D-MPRAGE did not improve lesion detection compared to 2D-T2SE. Multi-contrast, isotropic, single-slab 3D MRI allowed an improved detection of both GM and WM lesions compared to 2D-T2SE. A selection of single-slab 3D contrasts, for example, 3D-FLAIR and 3D-DIR, could replace 2D sequences in the radiological practice.

Purpose: To investigate whether a recently improved version of the three-dimensional double inversion-recovery (3D-DIR) technique enables the in vivo detection of hippocampal lesions in multiple sclerosis (MS). Materials and Methods:Magnetic resonance images of 16 patients and nine healthy control subjects were acquired at 1.5T. Lesions were scored on 3D-DIR images and were anatomically classified as white matter (WM), cortical, or hippocampal lesions. Associations between hippocampal, cortical, and WM lesion numbers were evaluated. Also, hippocampal lesions were retrospectively assessed on 3D-T2 and hippocampal and brain volumes were measured. Results:No hippocampal lesions were detected in control subjects. By contrast, 14 out of 16 MS patients had at least one hippocampal lesion. The mean number (ϮSD) of hippocampal lesions detected with 3D-DIR was 2.6 Ϯ 1.8 in MS patients; only 56% of these lesions could be observed on 3D-T2. Conclusion:Hippocampal lesions can be visualized in vivo with 3D-DIR and occur frequently in MS. The ability to visualize hippocampal lesions in vivo is of fundamental importance to future studies focusing on the role of gray matter (GM) damage in cognitive deficits, which are common in MS.