Abstract
Modern Computed Tomography (CT) scanners are capable of acquiring contrast dynamics of the whole brain, adding functional to anatomical information. Soft tissue segmentation is important for subsequent applications such as tissue dependent perfusion analysis and automated detection and quantification of cerebral pathology. In this work a method is presented to automatically segment white matter (WM) and gray matter (GM) in contrast- enhanced 4D CT images of the brain. The method starts with intracranial segmentation via atlas registration, followed by a refinement using a geodesic active contour with dominating advection term steered by image gradient information, from a 3D temporal average image optimally weighted according to the exposures of the individual time points of the 4D CT acquisition. Next, three groups of voxel features are extracted: intensity, contextual, and temporal. These are used to segment WM and GM with a support vector machine. Performance was assessed using cross validation in a leave-one-patient-out manner on 22 patients. Dice coefficients were 0.81 ± 0.04 and 0.79 ± 0.05, 95% Hausdorff distances were 3.86 ± 1.43 and 3.07 ± 1.72 mm, for WM and GM, respectively. Thus, WM and GM segmentation is feasible in 4D CT with good accuracy.
Highlights
Modern Computed Tomography (CT) scanners are capable of acquiring contrast dynamics of the whole brain, adding functional to anatomical information
CT is associated with harmful radiation and limited soft tissue contrast compared to Magnetic Resonance (MR), in many clinical application areas, for example emergency radiology, CT is the preferred modality due to its speed and widespread availability
In this work we present a method to segment white matter (WM) and gray matter (GM) in 4D CT images of the brain
Summary
Modern Computed Tomography (CT) scanners are capable of acquiring contrast dynamics of the whole brain, adding functional to anatomical information. In this work a method is presented to automatically segment white matter (WM) and gray matter (GM) in contrast- enhanced 4D CT images of the brain. Tissue attenuation curves obtained after contrast injection can be used to calculate perfusion values, such as blood flow and blood volume. This allows a combination of anatomical and functional imaging, with large coverage, using a single modality and a single acquisition. The hallmark of 4D CT is perfusion imaging of the brain to quantify parenchymal hemodynamics, for example in patients suffering from acute ischemic stroke. Soft tissue segmentation in CT is a research field that has been largely ignored in the past, even though the list of applications is large
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have