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Traumatic brain injury (TBI) is associated with high mortality due to intracranial pressure (ICP). Whether computed tomography (CT) scanning of the brain within the first 24 h is indicative of intracranial hypertension is largely unknown. We assessed the feasibility of semi-automated CT segmentation in comparison with invasive ICP measurements.CT volumetry of the brain might provide ICP data when invasive monitoring is not possible or is undesirable.We identified 33 patients with TBI who received a CT scan at admission and ICP monitoring within 24 h. Semi-automated segmentation of CT images in Matlab yielded cerebrospinal fluid (CSF) and intracranial volume (ICV) data. The ratio CSF/ICV × 100 (expressed as a percentage) was used as a proxy for ICP. The association between invasive ICP and the CSF/ICV ratio was evaluated using a simple linear regression model and a mono-exponential function derived from previous research in animals.ICP is moderately but significantly associated with the CSF/ICV ratio (r = -0.44, p = 0.01). The mono-exponential function provided a better fit of the relationship between ICP and the CSF/ICV ratio than the linear model.Our feasibility TBI data show that cross-sectional volumetric CT measures are associated with ICP. This non-invasive method can be used in future studies to monitor patients who are not candidates for invasive monitoring or to evaluate therapy effects objectively.

Introduction: Traumatic brain injury (TBI) is associated with high mortality due to intracranial pressure (ICP). Whether computed tomography (CT) scanning of the brain within the first 24 h is indicative of intracranial hypertension is largely unknown. We assessed the feasibility of semi-automated CT segmentation in comparison with invasive ICP measurements. Relevance: CT volumetry of the brain might provide ICP data when invasive monitoring is not possible or is undesirable. Methods: We identified 33 patients with TBI who received a CT scan at admission and ICP monitoring within 24 h. Semi-automated segmentation of CT images in Matlab yielded cerebrospinal fluid (CSF) and intracranial volume (ICV) data. The ratio CSF/ICV × 100 (expressed as a percentage) was used as a proxy for ICP. The association between invasive ICP and the CSF/ICV ratio was evaluated using a simple linear regression model and a mono-exponential function derived from previous research in animals. Results: ICP is moderately but significantly associated with the CSF/ICV ratio (r = −0.44, p = 0.01). The mono-exponential function provided a better fit of the relationship between ICP and the CSF/ICV ratio than the linear model. Conclusion: Our feasibility TBI data show that cross-sectional volumetric CT measures are associated with ICP. This non-invasive method can be used in future studies to monitor patients who are not candidates for invasive monitoring or to evaluate therapy effects objectively.

The generation of kinematic models of the heart using 3D echocardiography (echo) can be difficult due to poor image contrast and signal dropout, particularly at the epicardial surface. 2D echo images generally have a better contrast-to-noise ratio compared to 3D echo images, thus wall thickness (WT) estimates from 2D echo may provide a reliable means to constrain model fits to 3D echo images. WT estimates were calculated by solving a pair of differential equations guided by a vector field, which is constructed from the solution of Laplace’s equation on binary segmentations of the left ventricular myocardium. We compared 2D echo derived WT estimates against values calculated using gold-standard cardiac cine magnetic resonance imaging (MRI) to assess reliability. We found that 2D echo WT estimates were higher compared to WT values from MRI at end-diastole with a mean difference of 1.3 mm (95% CI: 0.74–1.8 mm), 1.5 mm (95% CI: 0.91–2.1 mm) and 2.1 mm (95% CI: 1.6–2.6 mm) for basal, mid-ventricular and apical segments respectively. At end-systole, the WT estimates from MRI were higher compared to those derived from 2D echo with a mean difference of 2.6 mm (95% CI: 2.0–3.1 mm), 2.1 mm (95% CI: 1.5–2.7 mm) and 1.1 mm (95% CI: 0.49–1.7 mm) for basal, mid-ventricular and apical segments, respectively. The quantitative WT comparison in this study will contribute to the ongoing efforts to better translate kinematic modelling analyses from gold-standard cardiac MRI to the more widely accessible echocardiography.