High-resolution cone beam CT for evaluation of vascular channel in intracranial partial thrombosed aneurysm

Abstract

The authors present a 60-year-old man with a partially thrombosed, intracranial vertebral artery aneurysm. A vascular channel in intra-aneurysmal thrombus was effectively identified with high-resolution cone beam CT (DynaCT Micro: Siemens Medical Solutions, Erlangen, Germany). Pre-procedural vertebral angiogram implied a perforating artery arising from near neck of the aneurysm and DynaCT Micro performed before approaching to the lesion demonstrated a vascular channel running in intra-aneurysmal thrombus which could not be distinguished from perforators with other imaging modalities. It was confirmed that perforators around the aneurysm were not identified and safely treated the aneurysm with stent-assisted coil embolization. High-resolution cone beam CT is enable to sharply visualize vessel lumens, thrombus, and intra-thrombus structures, and is useful to identify a vascular channel in intracranial partially thrombosed aneurysm.

Keywords: angiogram; cone beam CT; intracranial aneurysm; thrombosed aneurysm; vascular channel.

Fig. 1

Axial views of MRI T2 weighted image (A) and time of flight (B) shows VA aneurysm with intra-aneurysmal thrombus. (C) MRI BPAS (basi-parallel anatomical scanning showed the dilated outer membrane of the right VA, maximum diameter 12mm.

Fig. 2

Preprocedural right vertebral angiography of working projection showing a 6.6×6.6×3.6mm aneurysm, perforators arising from the proximal VA to the medulla (arrow head), and illustrating a tiny lumen arising form the near proximal neck of the aneurysm (arrow) in (a) anteroposterior and (b) lateral views.

Fig. 3

DynaCT Micro demonstrating that the tiny lumen was a vascular channel (arrow) running in the intra-aneurysmal thrombus (dot line) and was not a perforator feeding the brain stem in (a) coronal and (b) sagittal views of MPR image.

Fig. 4

(A) MIP image of conventional DynaCT showing deployed stent and induced microcatheter with jailing technique. Non-subtraction (B and C) and subtraction (D and E) right vertebral angiogram obtained after embolization. The patency of perforators arising the proximal VA was confirmed (arrow head).