Standard clinical computed tomography fails to precisely visualise presence, course and branching points of deep...

Standard computed tomography (CT) images have earned a well-established position in neuroimaging. Despite that, CT is somehow limited by its resolution, which does not enable to distinctively visualise structures smaller than 300 μm in diameter. Perforating arteries, most of which measure 100-400 μm in diameter, supply important subcortical structures (thalamus, basal ganglia, internal capsule). Consequently, pathologies affecting these vessels (e.g. lacunar strokes) can have a devastating clinical outcome. The aim of our study was to assess standard CT's ability to visualise perforators and compare it with microscopic and micro-CT pictures.

We have obtained 6 brainstem and 17 basal ganglia specimens. We infused them with barium sulphate contrast medium administered into either vertebral or internal cerebral artery. After that, the specimens were fixed in formalin and subsequently a series of CT, micro-CT and microscopic examinations were performed.

The median number of visualised perforators in brainstem and basal ganglia specimens was 8 and 3, respectively for CT and 18 and 7 for micro-CT (p < 0.05). Standard CT failed to clearly visualise branching points and vessels smaller than 0.25-0.5 mm (1-2 voxels) in diameter. Parallel vessels, like lenticulostriate arteries could not be differentiated in standard CT due to their proximity being smaller that the resolution.

Basing on our results, we infer that CT is a poor modality for imaging of the perforators, presenting both quantitative and qualitative flaws in contrast with micro-CT.