Integrated Short-TE and Hadamard-edited Multi-Sequence (ISTHMUS) for advanced MRS

• Published in: Journal of neuroscience methods Vol. 409; p. 110206
• Main Authors: Hui, Steve C.N., Murali-Manohar, Saipavitra, Zöllner, Helge J., Hupfeld, Kathleen E., Davies-Jenkins, Christopher W., Gudmundson, Aaron T., Song, Yulu, Yedavalli, Vivek, Wisnowski, Jessica L., Gagoski, Borjan, Oeltzschner, Georg, Edden, Richard A.E.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2024
• Subjects: Adult; Brain - diagnostic imaging; Brain - physiology; Female; Gray Matter - anatomy & histology; Gray Matter - diagnostic imaging; Hadamard encoding; HBCD; Humans; Magnetic Resonance Imaging - methods; Magnetic Resonance Spectroscopy - methods; Male; MR spectroscopy; PRESS; Reproducibility of Results; Spectral editing; White Matter - anatomy & histology; White Matter - diagnostic imaging; Young Adult; Spectral editing; HBCD; PRESS; MR spectroscopy; Hadamard encoding
• ISSN: 0165-0270; 1872-678X; 1872-678X
• DOI: 10.1016/j.jneumeth.2024.110206

To examine data quality and reproducibility using ISTHMUS, which has been implemented as the standardized MR spectroscopy sequence for the multi-site Healthy Brain and Child Development (HBCD) study. ISTHMUS is the consecutive acquisition of short-TE PRESS (32 transients) and long-TE HERCULES (224 transients) data with dual-TE water reference scans. Voxels were positioned in the centrum semiovale, dorsal anterior cingulate cortex, posterior cingulate cortex and bilateral thalamus regions. After acquisition, ISTHMUS data were separated into the PRESS and HERCULES portions for analysis and modeled separately using Osprey. In vivo experiments were performed in 10 healthy volunteers (6 female; 29.5±6.6 years). Each volunteer underwent two scans on the same day. Differences in metabolite measurements were examined. T2 correction based on the dual-TE water integrals were compared with: 1) T2 correction based on the default white matter and gray matter T2 reference values in Osprey and 2) shorter WM and GM T2 values from recent literature. No significant difference in linewidth was observed between PRESS and HERCULES. Bilateral thalamus spectra had produced significantly higher (p<0.001) linewidth compared to the other three regions. Linewidth measurements were similar between scans, with scan-to-scan differences under 1 Hz for most subjects. Paired t-tests indicated a significant difference only in PRESS NAAG between the two thalamus scans (p=0.002). T2 correction based on shorter T2 values showed better agreement to the dual-TE water integral ratio. ISTHMUS facilitated data acquisition and post-processing and reduced operator workload to eliminate potential human error. •ISTHMUS has been implemented into the HBCD study protocol.•It acquires both short-TE and Hadamard-edited transients.•ISTHMUS reduces operator workload.•ISTHMUS potentially allows improved T2 relaxation correction.