# Test-retest reliability of multi-metabolite edited MRS at 3T using PRESS and sLASER

Contact: Mark Mikkelsen, Ph.D. ([mam4041@med.cornell.edu](mailto:mam4041@med.cornell.edu))

## Overview

These data were collected as part of a study to assess the test-retest reliability of multi-metabolite edited MRS using [HERMES](https://doi.org/10.1016/j.neuroimage.2016.07.056) and [HERCULES](https://doi.org/10.1016/j.neuroimage.2018.10.002) editing and [PRESS](https://doi.org/10.1111/j.1749-6632.1987.tb32915.x) and [sLASER](https://doi.org/10.1002/mrm.21302) localization.

Data types included are defaced *T*<sub>1</sub>-weighted 3D structural MRI images and single-voxel HERMES- and HERCULES-edited PRESS and sLASER MRS data.

## Methods

### Participants

Sixteen healthy adults (10 females, 6 males, mean age = 38.4 ± 18.2 years).

**Important note**: Data of two participants (sub-05 and sub-06) was not uploaded to this repository because they did not provide the relevant consent for data sharing.
The data of the remaining 14 participants are available in this repository.

### Scanning

Two 1-hr scan sessions for each participant separated by a time interval (median = 0 days; range = 0-29 days).

### MR protocol

MR data were acquired on a 3T GE Discovery MR750 MRI scanner using a <sup>1</sup>H 32-channel RF phased-array head coil for receive and a body coil for transmit.

#### MRI

*T*<sub>1</sub>-weighted BRAVO structural MRI acquisition parameters:

- FSPGR
- TE/TR/TI = 5.2/12.2/725 ms
- Flip angle = 7°
- Voxel resolution = 0.9 × 0.9 × 1.5 mm<sup>3</sup>
- FOV = 256 × 256 mm<sup>2</sup>
- Matrix size = 256 × 256
- Slices = 124
- Parallel acquisition technique: GRAPPA
- Parallel acquisition factor: 2

#### MRS

General acquisition parameters:

- Volume of interest = medial parietal lobe
- Voxel resolution = 30 × 30 × 30 mm<sup>3</sup>
- Spectral width = 5000 Hz
- Number of points = 4096
- TE/TR = 82/2000 ms
- Number of transients = 224
- Duration = 7 min 28 s
- Double-echo GRE autoshimming
- OVS = 3 orthogonal slabs

HERMES:

- Target metabolites: GABA and GSH
- Two acquisitions: PRESS and sLASER
- CHESS water suppression

HERCULES:

- Target metabolites: GABA, GSH, ascorbate, aspartate, lactate, NAA, and NAAG
- Two acquisitions: PRESS and sLASER
- VAPOR water suppression