Comparative study of magnetic resonance and CT scan imaging in cases of severe head injury

Prognostic value of computed tomography and magnetic resonance imaging findings in acute traumatic brain injury in prediction of poor neurological outcome and mortality: a systematic review and meta-analysis

Traumatic brain injury (TBI) is a major cause of morbidity and mortality, impacting healthcare systems and economies. Early identification of poor outcomes is crucial for effective treatment. This systematic review assesses the prognostic value of computed tomography (CT) and magnetic resonance imaging (MRI) findings in predicting poor neurological outcomes and mortality in the acute phase of TBI. A comprehensive search of Scopus, MEDLINE, and Web of science databases was performed to identify studies examining CT and MR-based imaging findings and their association with poor outcomes as assessed by Glasgow outcome score as well as mortality within the early acute phase of TBI following injury/admission. Qualitative evaluation of included studies revealed several imaging sequences that modify the outcome of the patients, including extra-axial and intra-axial hemorrhage, swirl sign, contrast extravasation, midline shift, closed and open cranial cisterns, signs of edema, presence of cranial fractures, intracranial hemorrhage, cerebral microbleeds, diffuse axonal injury, apparent diffusion coefficient and fractional anisotropy in diffusion tensor imaging, as well as, concentrations of brain metabolites(N-acetyl aspartate, Creatinine, Choline, Myo-inositol, glutamate, and glutamine) in magnetic resonance spectroscopy. Among these markers, subarachnoid hemorrhage (SAH) and subdural hematoma (SDH) emerged as the most predictive of poor outcomes based on meta-analysis findings. SAH was significantly associated with an increased risk of mortality (OR: 3.35, 95% CI: 2.41-4.65, I²=51.3%) and poor outcomes (OR: 2.69, 95% CI: 2.44-2.96, I²=0%). Similarly, SDH correlated with higher mortality risk (OR: 2.44, 95% CI: 2.14-2.78, I²=0%) and worse outcomes (OR: 2.00, 95% CI: 1.12-3.59, I²=60.9%). In contrast, epidural hematoma (EDH) was linked to better outcomes (OR: 0.60, 95% CI: 0.52-0.68, I²=0%) but not significantly associated with mortality (OR: 0.38, 95% CI: 0.09-1.65, I²=73.7%). The results of this systematic review and meta-analysis provide an overview of clinically feasible imaging markers of prognostic value and may inform clinical decision-making in the future.

Use of multisequence 3.0-T MRI to detect severe traumatic brain injury and predict the outcome

OBJECTIVE

The aim of this study was to evaluate multisequence 3.0-T MRI in the detection of severe traumatic brain injury (sTBI) and in predicting the outcome.

METHODS

32 patients with sTBI were prospectively enrolled, and multisequence 3.0-T MRI was performed 4-8 weeks post injury. Quantitative data were recorded on each sequence. The ability to display the parenchymal lesions was compared with that of 64-slice spiral CT. The clinical and radiological results were correlated with the Glasgow Outcome Scale Extended scores 6 months after injury.

RESULTS

3.0-T MRI could display more lesions than CT, especially when the lesion was deeply located. The lesion volumes and diffuse axonal injury (DAI) scores were different between good and poor outcome groups on fluid attenuated inversion recovery (p < 0.05). The apparent diffusion coefficient (ADC) values of the splenium of the corpus callosum and brain stem were also different (p < 0.05). Patients with unfavourable outcome showed a significantly higher volume of haemorrhage on susceptibility-weighted imaging than those with favourable outcomes and had haemorrhages generally located more deeply. Logistic regression analysis revealed that the location of haemorrhage and the ADC values of the splenium of the corpus callosum were independent risk factors for poor outcome, with an overall predictive accuracy of 91.4%.

CONCLUSION

The joint use of conventional and advanced sequences of 3.0-T MRI can comprehensively detect the pathological changes occurring after sTBI. Haemorrhagic and non-haemorrhagic DAIs in deep structures strongly suggest poor outcome.

ADVANCES IN KNOWLEDGE

This article improves the understanding of advanced MRI sequences in the detection of patients with sTBI and prediction of prognosis.

Diffusion tensor imaging biomarkers for traumatic axonal injury: analysis of three analytic methods

Traumatic axonal injury (TAI) is a common mechanism of traumatic brain injury not readily identified using conventional neuroimaging modalities. Novel imaging modalities such as diffusion tensor imaging (DTI) can detect microstructural compromise in white matter (WM) in various clinical populations including TAI. DTI-derived data can be analyzed using global methods (i.e., WM histogram or voxel-based approaches) or a regional approach (i.e., tractography). While each of these methods produce qualitatively comparable results, it is not clear which is most useful in clinical research and ultimately in clinical practice. This study compared three methods of analyzing DTI-derived data with regard to detection of WM injury and their association with clinical outcomes. Thirty patients with TAI and 19 demographically similar normal controls were scanned using a 3 Tesla magnet. Patients were scanned approximately eight months postinjury, and underwent an outcomes assessment at that time. Histogram analysis of fractional anisotropy (FA) and mean diffusivity showed global WM integrity differences between patients and controls. Voxel-based and tractography analyses showed significant decreases in FA within centroaxial structures involved in TAI. All three techniques were associated with functional and cognitive outcomes. DTI measures of microstructural integrity appear robust, as the three analysis techniques studied showed adequate utility for detecting WM injury.

In vivo characterization of traumatic brain injury neuropathology with structural and functional neuroimaging

Quantitative neuroimaging is increasingly used to study the effects of traumatic brain injury (TBI) on brain structure and function. This paper reviews quantitative structural and functional neuroimaging studies of patients with TBI, with an emphasis on the effects of diffuse axonal injury (DAI), the primary neuropathology in TBI. Quantitative structural neuroimaging has evolved from simple planometric measurements through targeted region-of-interest analyses to whole-brain analysis of quantified tissue compartments. Recent studies converge to indicate widespread volume loss of both gray and white matter in patients with moderate-to-severe TBI. These changes can be documented even when patients with focal lesions are excluded. Broadly speaking, performance on standard neuropsychological tests of speeded information processing are related to these changes, but demonstration of specific brain-behavior relationships requires more refined experimental behavioral measures. The functional consequences of these structural changes can be imaged with activation functional neuroimaging. Although this line of research is at an early stage, results indicate that TBI causes a more widely dispersed activation in frontal and posterior cortices. Further progress in analysis of the consequences of TBI on neural structure and function will require control of variability in neuropathology and behavior.

Neuroimaging in traumatic brain imaging

Traumatic brain injury (TBI) is a common and potentially devastating clinical problem. Because prompt proper management of TBI sequelae can significantly alter the clinical course especially within 48 h of the injury, neuroimaging techniques have become an important part of the diagnostic work up of such patients. In the acute setting, these imaging studies can determine the presence and extent of injury and guide surgical planning and minimally invasive interventions. Neuroimaging also can be important in the chronic therapy of TBI, identifying chronic sequelae, determining prognosis, and guiding rehabilitation.

Functional reorganisation of memory after traumatic brain injury: a study with H(2)(15)0 positron emission tomography

OBJECTIVE

To study the effects of moderate to severe traumatic brain injury (TBI) on the functional neuroanatomy supporting memory retrieval.

METHODS

Subjects were six patients who had sustained a moderate to severe TBI about four years before scanning and had since made a good recovery. Eleven healthy young adults matched to the patients for age and education served as controls. An established H(2)(15)0 positron emission tomography paradigm was used to elicit brain activations in response to memory retrieval. TBI patients' patterns of brain activation were compared statistically with those of control subjects. Both group and individual case data were analysed.

RESULTS

Both TBI patients and controls engaged frontal, temporal, and parietal regions known to be involved in memory retrieval, yet the TBI patients showed relative increases in frontal, anterior cingulate, and occipital activity. The hemispheric asymmetry characteristic of controls was attenuated in patients with TBI. Reduced activation was noted in the right dorsomedial thalamus. Although local aspects of this pattern were affected by the presence of focal lesions and performance differences, the overall pattern was reliable across patients and comparable to functional neuroimaging results reported for normal aging, Alzheimer's disease, and other patients with TBI.

CONCLUSIONS

The TBI patients performed memory tasks using altered functional neuroanatomical networks. These changes are probably the result of diffuse axonal injury and may reflect either cortical disinhibition attributable to disconnection or compensation for inefficient mnemonic processes.