A Decade of DTI in Traumatic Brain Injury: 10 Years and 100 Articles Later

Abstract

SUMMARY:The past decade has seen an increase in the number of articles reporting the use of DTI to detect brain abnormalities in patients with traumatic brain injury. DTI is well-suited to the interrogation of white matter microstructure, the most important location of pathology in TBI. Additionally, studies in animal models have demonstrated the correlation of DTI findings and TBI pathology. One hundred articles met the inclusion criteria for this quantitative literature review. Despite significant variability in sample characteristics, technical aspects of imaging, and analysis approaches, the consensus is that DTI effectively differentiates patients with TBI and controls, regardless of the severity and timeframe following injury. Furthermore, many have established a relationship between DTI measures and TBI outcomes. However, the heterogeneity of specific outcome measures used limits interpretation of the literature. Similarly, few longitudinal studies have been performed, limiting inferences regarding the long-term predictive utility of DTI. Larger longitudinal studies, using standardized imaging, analysis approaches, and outcome measures will help realize the promise of DTI as a prognostic tool in the care of patients with TBI. ABBREVIATIONS:FA ϭ fractional anisotropy; GCS ϭ Glasgow Coma Scale; MD ϭ mean diffusivity; TAI ϭ traumatic axonal injury; TBI ϭ traumatic brain injury;

Advanced neuroimaging in the clinic: critical appraisal of the evidence base

“…We classified all reviews addressing outcome prediction, whether DTI-mTBI or DSC-glioma, as descriptive (Figure 2), although some quantitative reviews did incorporate longitudinal studies. 8 Regarding CEBM review quality grades for detection reviews, three DTI-mTBI reviews were given a grade of 1a and one review was given a grade of 2b (Table 4). One DSC-glioma review was assigned a grade of 1b ( Table 2).…”

“…Thus, 23 DTI-mTBI 6,8, and 26 DSC-glioma 7,9,12,45-67 review articles were included in the analysis.…”

“…We classified 5/23 DTI-mTBI detection reviews 8,24,29,34,36 and 1/26 DSC-glioma detection reviews 7 as systematic/quantitative reviews ( Figure 2). We classified all reviews addressing outcome prediction, whether DTI-mTBI or DSC-glioma, as descriptive (Figure 2), although some quantitative reviews did incorporate longitudinal studies.…”

“…Traumatic axonal injury (TAI) is the primary pathologic feature of mTBI and is not detectable by CT or structural MRI unless, uncommonly, it is associated with haemorrhage. 8 Diffusion tensor imaging (DTI), however, detects TAI as a reduction of the normal directional coherence of water diffusion in white matter. 8 Glioma infiltrates white matter tracts, 9,10 a phenomenon that conventional contrast-enhanced CT and MRI are unable to fully detect.…”

“…8 Diffusion tensor imaging (DTI), however, detects TAI as a reduction of the normal directional coherence of water diffusion in white matter. 8 Glioma infiltrates white matter tracts, 9,10 a phenomenon that conventional contrast-enhanced CT and MRI are unable to fully detect. 9,11 DSC-MRI, however, detects glioma infiltration as elevated CBV due to tumour neoangiogenesis within the normal-appearing white matter of the peritumoral region.…”