Fig 2.

Comparison of manual segmentation of cerebral T2 hyperintense lesions at 4 NAIMS sites. 3T MR imaging scans on Siemens scanners from a single subject with multiple sclerosis showing T2 hyperintense lesions from sagittal fluid-attenuated inversion recovery sequences from 4 different North American Imaging in Multiple Sclerosis Cooperative sites and scanner models: Brigham and Women's Hospital, Skyra; National Institutes of Health, Skyra; Oregon Health & Science University (OHSU), Tim Trio; Cedars-Sinai, Verio. The upper panel shows the native images. The lower panel shows zoomed and cropped images to illustrate the key findings. The green arrow (lower panel) shows a possible lesion detected and traced on the National Institutes of Health scan; the red arrow shows the same lesion not detected by the expert procedure on the Brigham and Women's Hospital scan. The purple arrow shows a similar tubular area interpreted as a blood vessel on the Cedars-Sinai scan, which was not selected as a lesion by the expert tracing; no lesion was detected on the Oregon Health & Science University scan in this area on this section or any of the adjacent sections (not shown). The blue arrow shows a different lesion detected and traced on the Brigham and Women's Hospital, National Institutes of Health, and Cedars-Sinai scans but not detected by the expert review on the Oregon Health & Science University scan, appearing hazy/subtle (white arrow). The yellow arrow (upper panel) shows a lesion on all scans; however, when we added the tracing of all sections showing the lesion, the 3D volume of the lesion differed among sites: Brigham and Women's Hospital = 0.059 mL, National Institutes of Health = 0.053 mL, Oregon Health & Science University = 0.033 mL, Cedars-Sinai = 0.053 mL.