Longitudinal MR Spectroscopy Shows Altered Metabolism in Traumatic Brain Injury

Abstract

BACKGROUND AND PURPOSE Brain trauma is known to result in heterogeneous patterns of tissue damage and altered neuronal and glial metabolism that evolve over time following injury; however, little is known on the longitudinal evolution of these changes. In this study, magnetic resonance spectroscopic imaging (MRSI) was used to map the distributions of altered metabolism in a single subject at five time points over a period of 28 months following injury. METHODS MRI and volumetric MRSI data was acquired in a subject that had experienced a moderate traumatic brain injury (Glasgow Coma Scale 13) at five time points, from 7 weeks to 28 months after injury. Maps of N-acetylaspartate (NAA), total choline (Cho), and total creatine signal were generated and differences from normal control values identified using a z-score image analysis method. RESULTS The z-score metabolite maps revealed areas of significantly reduced NAA and increased Cho, predominately located in frontal and parietal white matter, that evolved over the complete course of the study. A map of the ratio of Cho/NAA showed the greatest sensitivity to change, which indicated additional metabolic changes throughout white matter. The metabolic changes reduced over time following injury, though with abnormal values remaining in periventricular regions. CONCLUSIONS The use of z-score image analysis for MRSI provides a method for visualizing diffuse changes of tissue metabolism in the brain. This image visualization method is of particularly effective for visualizing widespread and diffuse metabolic changes, such as that due to traumatic injury.

Longitudinal Metabolite Changes after Traumatic Brain Injury: A Prospective Pediatric Magnetic Resonance Spectroscopic Imaging Study

“…The use of Cr in ratios adds uncertainties, given that alterations of Cr have been reported in some brain injury studies, 14,51 but not others. 19,52 This may have masked changes in Cho, reported as Cho/Cr ratios, which were smaller in magnitude than NAA changes, given that we and others using varying techniques have previously shown significant elevations in Cho early after TBI. 16,19 After visual inspection of the spectra, we are confident that detected reductions of NAA ratios were attributed primarily to NAA reductions, rather than elevated Cr or Cho levels.…”

Reproducibility of whole‐brain temperature mapping and metabolite quantification using proton magnetic resonance spectroscopy

“…Proton magnetic resonance spectroscopy ( 1 H‐MRS) has been widely applied to quantify brain metabolite changes in humans 1–6 . Another relatively new, but promising application of 1 H‐MRS is the noninvasive measurement of brain temperature 7–9 .…”

The Clinical Utility of Magnetic Resonance Spectroscopy in Traumatic Brain Injury: Recommendations from the ENIGMA MRS Working Group

“…whether regional or whole-brain, have consistently been associated with outcomes following moderate to severe TBI (Friedman, Brooks, Jung, Hart, & Yeo, 1998;Garnett et al, 2000;Holshouser et al, 2005;Maudsley et al, 2017). Longitudinal studies have…”

“…Several studies have correlated reduced NAA levels after injury to long-term memory or attention deficits (Babikian et al, 2006;Holshouser et al, 2019) and combined neuropsychological function measures (Friedman et al, 1998;Govind et al, 2010;Maudsley et al, 2015;Babikian et al, 2018;Dennis et al, 2018). Increasing levels of Cho (Maudsley et al, 2017), mIns (Ashwal et al, 2004), and Glx (Ashwal et al, 2004;Garnett et al, 2001;Gasparovic et al, 2009;Shutter, Tong, & Holshouser, 2004) have also been associated with poor neurological outcome. The presence of Lac and lipids after severe TBI has been reported in patients with the worst outcomes (Ashwal et al, 1997;Panigrahy, Nelson, & Blüml, 2010).…”

“…Three-dimensional volumes are usually centered around the corpus callosum to cover these regions and the deep gray matter (George et al, 2014;Kirov et al, 2007;Holshouser et al, 2019;Sours et al, 2015), while whole-brain coverage techniques by default cover most of the supratentorial brain (Govind et al, 2010;Maudsley et al, 2015;Widerström-Noga, Govind, Adcock, Levin, & Maudsley, 2016;Maudsley et al, 2017;Babikian et al, 2018;Dennis et al, 2018). While there is no literature consensus on which exact brain region(s) to study with either SVS or MRSI, recent evidence suggests that for maximum sensitivity to white matter injury, location is less important than the sensitivity of the method (Davitz et al, 2019).…”