Shining light on neurovascular disease

Abstract

Tortuosity and fragility of the intracranial vasculature have precluded the application of novel intravascular imaging modalities during the treatment of cerebrovascular pathologies. In other circulatory beds, these technologies have transformed clinical and therapeutic decision-making. A new report demonstrates the clinical use of high-resolution intravascular imaging in the human cerebrovasculature using neuro optical coherence tomography. This technology provides an unprecedented opportunity to examine the luminal dimensions of cerebrovascular disease. We expect that the neurointerventional community will rapidly adopt this technology-similar to wider adoptions by other vascular specialties-for both a better understanding of underlying disease and clarity of endovascular therapeutic safety and effectiveness.

Keywords: High resolution; intravascular imaging; neuro optical coherence tomography; neurovascular disease; technique-technology.

Figure 1.

Representative examples of nOCT imaging. (A) DSA image from a case with extensive ICA tortuosity (arrows). The dashed line in the M2 segment of the middle cerebral artery shows the location of the cross-sectional nOCT image depicted in (B). (B) Despite severe tortuosity, the nOCT image presents uniform brightness and contrast, as well as the absence of rotational distortion and other artifacts. nOCT shows clear details of the arterial wall microstructure, presenting a three-layer normal appearance (dotted square inset). The tunica media (lower arrow in B) is seen as a darker layer between the tunica intima and adventitia, showing a bright appearance. The artery is surrounded by CSF. Due to the transparent properties of the CSF to near-infrared light, nOCT visualizes the extravascular space with clarity. The arrow points to the location of small perforating arteries. The asterisk (*) indicates the location of a vein. The vein's lumen appears opaque to nOCT as it is filled with blood, a distinctive characteristic as compared to arteries that are rapidly filled with contrast after injections. The scale bars are equal to 1 mm. (C) DSA imaging of a restenosed stent in the intracranial segment of the vertebral artery (V4) (arrow). (D) No intraluminal thrombus is observed on nOCT and the tissue causing the restenosis appears eccentric, showing two distinct layers. A uniform, smooth and bright inner layer (arrows) suggests the presence of organized smooth muscle cells. A deeper layer with a dark, heterogeneous appearance indicates possible proteoglycan content and fibrin deposition (asterisks). The scale bars are equal to 1 mm. Images adapted from Pereira et al.