Volumetric Analysis from a Harmonized Multisite Brain MRI Study of a Single Subject with Multiple Sclerosis

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.

Comparison of manual and automated methods for measuring lesional volume. Scan-rescan imaging is shown by using multiple dots for each site and algorithm. UCSF indicates University of California, San Francisco; JHU, Johns Hopkins University; OHSU, Oregon Health & Science University.

FSL-FIRST automated segmentation results: thalamus. Representative anatomic section showing segmentation of the thalamus (green) in the single subject. The segmentation maps are overlaid to the original raw 3D T1-weighted images after re-orientation to the axial plane. Segmentation was performed by the fully automated FSL-FIRST pipeline. The scan site and 3T Siemens model are shown for each image. The first 2 scans are from the scan/re-scan at Brigham and Women's Hospital. OHSU indicates Oregon Health & Science University.

Comparison of automated methods for measuring thalamic volume. Scan-rescan imaging is shown by using multiple dots for each site and algorithm. UCSF indicates University of California, San Francisco; JHU, Johns Hopkins University; OHSU, Oregon Health & Science University.

Estimated across-site coefficient of variation for each structure with various methods for volumetric measurement. cGM indicates cortical gray matter; NAWM, normal-appearing white matter; TBV, total brain volume.

Estimated proportion of variation explained by site for using various segmentation methods for different structures in the brain. cGM indicates cortical gray matter; NAWM, normal-appearing white matter; TBV, total brain volume.