The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.
Magn Reson Med. 2024 Feb;91(2):431-442. doi: 10.1002/mrm.29895. Epub 2023 Oct 24.
To compare the respective ability of PRESS and sLASER to reveal biological relationships, using age as a validation covariate at 3 T.
MRS data were acquired from 102 healthy volunteers using PRESS and sLASER in centrum semiovale and posterior cingulate cortex (PCC). Acquisition parameters included TR/TE = 2000/30 ms, 96 transients, and 2048 datapoints sampled at 2 kHz. Spectra were analyzed using Osprey. SNR, FWHM linewidth of total creatine, and metabolite concentrations were extracted. A linear model was used to compare SNR and linewidth. Paired t-tests were used to assess differences in metabolite measurements between PRESS and sLASER. Correlations were used to evaluate the relationship between PRESS and sLASER metabolite estimates, as well as the strength of each metabolite-age relationship. Coefficients of variation were calculated to assess inter-subject variability in each metabolite measurement.
SNR and linewidth were significantly higher (p < 0.01) for sLASER than PRESS in PCC. Paired t-tests showed significant differences between PRESS and sLASER in most metabolite measurements. PRESS-sLASER measurements were significantly correlated (p < 0.05) for most metabolites. Metabolite-age relationships were consistently identified using both methods. Similar coefficients of variation were observed for most metabolites.
The study results suggest strong agreement between PRESS and sLASER in identifying relationships between brain metabolites and age in centrum semiovale and PCC data acquired at 3 T. sLASER is technically desirable due to the reduced chemical shift displacement artifact; however, PRESS performed similarly in homogeneous brain regions at clinical field strength.
在 3T 下，以年龄为验证协变量，比较 PRESS 和 sLASER 揭示生物学关系的各自能力。
使用 PRESS 和 sLASER 在大脑半卵圆中心和后扣带回皮质（PCC）采集 102 名健康志愿者的 MRS 数据。采集参数包括 TR/TE=2000/30ms、96 次瞬态和 2048 个数据点，以 2kHz 进行采样。使用 Osprey 分析光谱。提取 SNR、总肌酸 FWHM 线宽和代谢物浓度。使用线性模型比较 SNR 和线宽。使用配对 t 检验评估 PRESS 和 sLASER 之间代谢物测量值的差异。使用相关分析评估 PRESS 和 sLASER 代谢物估计值之间的关系，以及每个代谢物-年龄关系的强度。计算变异系数以评估每个代谢物测量的个体间变异性。
PCC 中，sLASER 的 SNR 和线宽均显著高于 PRESS（p<0.01）。配对 t 检验显示 PRESS 和 sLASER 之间在大多数代谢物测量值上存在显著差异。PRESS-sLASER 测量值在大多数代谢物上显著相关（p<0.05）。两种方法均能一致地识别代谢物与年龄之间的关系。大多数代谢物的变异系数相似。
研究结果表明，在 3T 下采集的大脑半卵圆中心和 PCC 数据中，PRESS 和 sLASER 在识别脑代谢物与年龄之间的关系方面具有很强的一致性。由于化学位移位移伪影减少，sLASER 在技术上是理想的；但是，在临床场强下，PRESS 在同质脑区的表现相似。
