Post-mortem imaging of the infant and perinatal dura mater and superior sagittal sinus using optical coherence tomography

Infants and young children are likely to present with subdural haemorrhage (SDH) if they are the victims of abusive head trauma. In these cases, the most accepted theory for the source of bleeding is the bridging veins traversing from the surface of the brain to the dura mater. However, some have suggested that SDH may result from leakage of blood from a dural vascular plexus. As post-mortem examination of the bridging veins and dura is challenging, and imaging modalities such as magnetic resonance and computed tomography do not have the resolution capabilities to image small blood vessels, we have trialled the use of intravascular and benchtop optical coherence tomography (OCT) systems for imaging from within the superior sagittal sinus (SSS) and through the dura during five infant/perinatal autopsies. Numerous vessel-like structures were identified using both OCT systems. Measurements taken with the intravascular rotational system indicate that the approximate median diameters of blood vessels entering anterior and posterior segments of the SSS were 110 μm (range 70 to 670 μm, n = 21) and 125 μm (range 70 to 740 μm, n = 23), respectively. For blood vessels close to the wall of the SSS, the median diameters for anterior and posterior segments of the SSS were 80 μm (range 40 to 170 μm, n = 25) and 90 μm (range 30 to 150 μm), respectively. Detailed characterisation of the dural vasculature is important to aid understanding of the source of SDH. High resolution 3-dimensional reconstructions of the infant dural vasculature may be possible with further development of OCT systems.