Journal: Scientific Reports

Article Title: Optimized multi-echo gradient-echo magnetic resonance imaging for gray and white matter segmentation in the lumbosacral cord at 3 T

doi: 10.1038/s41598-022-20395-1

Figure Lengend Snippet: ( A ) Sagittal T2-weighted turbo spin echo acquisition in the lower spine used for subsequent prescription of the high-resolution axial acquisition. ( B ) Corresponding axial slices acquired with the 3D multi-echo gradient-echo sequence ( Siemens FLASH) in the caudal-rostral direction (slices 1–20). Highlighted are the slice in the lumbosacral enlargement (LSE) with the largest cord cross-sectional spinal cord area (defined as the "LSE slice" and shown in light blue in A and B ; here: slice 15), and the most caudal slice in the conus medullaris (CM) where the gray matter still has the characteristic butterfly shape (defined as the "CM slice" and shown in red in A and B ; here: slice 9). A saturation band, displayed as yellow shaded area in A, was placed anterior to the spine to suppress signal and possible artifacts arising from abdominal peristalsis.

Article Snippet: The 3D spoiled multi-echo gradient echo sequence (Siemens FLASH) consisted of 5 echoes and was acquired with 8 individual repetitions.

Techniques: Sequencing

Journal: Scientific Reports

Article Title: Optimized multi-echo gradient-echo magnetic resonance imaging for gray and white matter segmentation in the lumbosacral cord at 3 T

doi: 10.1038/s41598-022-20395-1

Figure Lengend Snippet: Visual representation of echoes, echo combinations, signal averages, and image segmentations. The 3D spoiled multi-echo gradient echo sequence (Siemens FLASH) consisted of 5 echoes and was acquired with 8 individual repetitions. For each subject, a series of images was created by successively combining echoes (echo 1, 1–2, 1–3, 1–4, 1–5) and averaging across repetitions (number of signal averages (NSA): 1, 2, 3, …, 8), resulting in a total of 72 images. ( A ) Image series of individual echoes (NSA = 8) for a representative slice in the lumbosacral enlargement (LSE). ( B ) Image series of increasing number of combined echoes in the same slice as in ( A ) (NSA = 8). ( C ) Image series with increasing NSA (3 combined echoes). ( D ) Spinal cord (SC) and gray matter (GM) were segmented manually in each slice (here a representative LSE and conus medullaris slice are shown). A mask of cerebrospinal fluid (CSF) was drawn anterior to the SC. White matter (WM) mask was obtained by subtracting GM from the SC mask.

Article Snippet: The 3D spoiled multi-echo gradient echo sequence (Siemens FLASH) consisted of 5 echoes and was acquired with 8 individual repetitions.

Techniques: Sequencing