High-resolution deuterium metabolic imaging of the human brain at 9.4 T using bSSFP spectral-spatial acquisitions

In this clinical translational study, the feasibility of using bSSFP acquisitions to improve [6,6’-²H₂]-glucose DMI in the healthy human brain at 9.4 T is investigated. To this end, bSSFP sequences employing two popular 3D encoding schemes, namely chemical shift imaging (CSI) and spectroscopic multi echo, were compared. For both bSSFP acquisition types, phase cycling was incorporated to enhance robustness against the substantial B₀ inhomogeneity in the human head. Two spectral fitting methods were developed for the phase-cycled bSSFP data to obtain reliable and SNR optimal metabolite maps. The SNR performance and spectral-spatial encoding of these two bSSFP acquisition schemes were compared to the vendor’s standard implementation consisting of a gradient spoiled 3D CSI sequence without RF-spoiling (FISP/lowest-order SSFP-FID). The DMI protocols were designed to maximize SNR based on the simulation of the acquired signal utilizing the measured in vivo T1, T2 and T2* relaxation times. The spectral separation of the designed protocols was verified using a phantom containing all four (water, glucose, glutamic acid and lactate) deuterated compounds detected in in vivo [6,6’-²H₂]-glucose DMI.

Data Contents

The data is shared in Siemen raw data format. The software for processing these data can be found under : https://github.com/praveenivp/DeuteMetCon.git . The files are named according to the sequence and protocol name.

• CSI-FISP (*rpcsi_fid*.dat)
• CSI-bSSFP (*rpcsi_ssfp*.dat)
• ME-bSSFP (*pvrh_trufi*.dat)

phantom-DMI.tar.gz

├── MID01419_rpfid.dat
├── MID01423_rpcsi_fid_Stan_TR36.dat
├── MID01425_rpcsi_ssfp_TR19.dat
├── MID01426_piv_gre_B0mapping_5E.dat
├── MID01427_pvrh_trufi_noise_.dat
└── MID01428_pvrh_trufi_5E_18PC_12P5mm_FA50.dat

sub-[01-03]-DMI.tar.gz

├── anat
│   ├── brain_sag.nii
│   └── brain_tra.nii
├── M1000#D230924#T095442#rpcsi_ssfp_Stan25_156mm.dat
├── M1006#D230924#T100758#AdjXFre.dat
├── M1011#D230924#T103002#pvrh_trufi_5E_18PC_12P5mm_FA50_.dat
├── M983#D230924#T085235#rpcsi_fid_Stan_res156_moreopti.dat
├── M987#D230924#T090324#rpcsi_ssfp_Stan25_156mm.dat
├── M990#D230924#T091440#pvrh_trufi_5E_18PC_12P5mm_FA50_.dat
├── M991#D230924#T092455#pvrh_trufi_5E_noise_12P5mm.dat
├── M997#D230924#T093336#rpcsi_fid_Stan_res156_moreopti.dat
└── M999#D230924#T094413#pvrh_trufi_5E_18PC_12P5mm_FA50_.dat

Relaxometry.tar.gz

├── phantom
│   ├── meas_MID00059_FID03976_pvrh_Noise.dat
│   ├── meas_MID00147_FID04039_T1_nonsel_inv_10min.dat
│   ├── meas_MID00202_FID04072_Transmitt.dat
│   ├── meas_MID00239_FID04096_T2_nonsel_10mins.dat
│   └── meas_MID01429_FID00182_pulseq_Transmitter.dat
├── pulseq
│   ├── T1_nonsel_FOCI_2H_10min.seq
│   ├── T2_nonsel_2H_10min.seq
│   └── trans_adjust_2H_1min.seq
├── sub-01
│   ├── M1006#D230924#T100758#AdjXFre.dat
│   ├── M1008#D230924#T100835#pulseq_T1_10mins.dat
│   ├── M1009#D230924#T101852#pulseq_T2_10mins.dat
│   ├── M1010#D230924#T102854#pulseq_Transmitter.dat
│   ├── M1012#D230924#T104018#rpfid-T1.dat
│   └──M991#D230924#T092455#pvrh_trufi_5E_noise_12P5mm.dat
├── sub-02
│   ├── M1157#D101024#T093549#pvrh_trufi_5E_noise_12P5mm.dat
│   ├── M1171#D101024#T100807#pulseq_Transmitter.dat
│   ├── M1172#D101024#T100929#pulseq_T1_10mins.dat
│   ├── M1173#D101024#T101930#pulseq_T2_10mins.dat
│   └── M1174#D101024#T103039#AdjXFre.dat
├── sub-03
│   ├── M103#D281124#T113256#pvrh_trufi_5E_noise_12P5mm.dat
│   ├── M107#D281124#T113842#AdjXFre.dat
│   ├── M108#D281124#T113850#pulseq_Transmitter.dat
│   ├── M110#D281124#T114114#pulseq_T1_10mins.dat
│   ├── M111#D281124#T115116#pulseq_T2_10mins.dat
│   └── T1_final_amares.fig
├── sub-04
│   ├── M415#D220124#T095645#pvrh_trufi_14mm_noise.dat
│   ├── M420#D220124#T101033#pulseq_T2_10mins.dat
│   ├── M422#D220124#T102143#pulseq_T1_invFOCI_10mins.dat
│   └── M423#D220124#T103144#pulseq_transmitter.dat
└── sub-05
    ├── M690#D220524#T091312#pvrh_trufi_5E_noise_12P5mm.dat
    ├── M703#D220524#T095527#pulseq_T2_10mins.dat
    ├── M707#D220524#T101220#pulseq_T1_10mins.dat
    ├── M709#D220524#T102309#AdjXFre.dat
    └── M714#D220524#T103143#pulseq_Transmitter.dat

changes in v2:

uploaded one more subject, phanton-DMI-4rep dataset and new code.