Abstract
<jats:p> Background: Multiple sclerosis subpial cortical lesions are prevalent and associated with disability but difficult to detect on MRI. Inversion recovery susceptibility weighted imaging with enhanced T <jats:sub>2</jats:sub> weighting (IR-SWIET) and T <jats:sub>1</jats:sub> /T <jats:sub>2</jats:sub> ratio imaging have been proposed for cortical lesion detection on 3 tesla (T) MRI. Objectives: To assess cortical lesion detection using IR-SWIET and T <jats:sub>1</jats:sub> /T <jats:sub>2</jats:sub> ratio imaging. Methods: Cortical lesions were identified in 20 persons with MS (pwMS) independently on six image sets: T <jats:sub>1</jats:sub> weighted (w) magnetization prepared 2 rapid acquisition gradient echoes (MP2RAGE) + T <jats:sub>2</jats:sub> w fluid attenuated inversion recovery (FLAIR) alone or with T <jats:sub>1</jats:sub> /T <jats:sub>2</jats:sub> , IR-SWIET single acquisition (×1), average of two (×2) or median of four (×4) acquisitions, or denoised single acquisition (IR-SWIET×1DN). In 10 additional pwMS with 7T-based cortical lesion segmentations, lesions were identified on MP2RAGE + FLAIR + IR-SWIET×1DN. Results: Median subpial lesions identified on MP2RAGE + FLAIR was 0 (interquartile range (IQR) 2) vs 0 with T <jats:sub>1</jats:sub> /T <jats:sub>2</jats:sub> (IQR 1, p=0.07), 1 with IR-SWIET×1 (IQR 6, p=0.42), 5 with IR-SWIET×2 (IQR 5, p=0.008), 4 with IR-SWIET×4 (IQR 6, p=0.008), and 4 with IR-SWIET×1DN (IQR 6, p=0.008). Versus 7T, IR-SWIET×1DN detected subpial lesions with similar sensitivity to IR-SWIET×2. Conclusions: IR-SWIET, but not T <jats:sub>1</jats:sub> /T <jats:sub>2</jats:sub> , improves subpial cortical lesion detection. Denoising may be an efficient and sensitive alternative to multi-acquisition averaging. </jats:p>