Characteristic image on cerebral angiography in ruptured blood blister-like aneurysms

To evaluate the static and dynamic features of blood blister-like aneurysms (BBAs) using cerebral angiography to identify characteristic features to improve the diagnosis of these uncommon aneurysms.

Digital subtraction angiography (DSA) images were compared between patients with BBAs (n = 12, group A) and patients with unruptured paraclinoid aneurysms ≤ 5 mm in size treated by endovascular procedures (n = 12, group B). DSA images were assessed for irregularities in the diameter of the parent artery and delayed inflow and outflow of contrast medium in the aneurysm. Enlargement of the aneurysm and morphological changes from the first assessment were also evaluated in patients with BBAs.

Compared to the group B, group A had a higher proportion of irregular vessel diameter (p = 0.013) and the delayed contrast medium outflow (p = 0.014). As well, stagnation of contrast medium along the aneurysm wall was a characteristic finding of BBAs, even for small aneurysms.

Irregular morphological features of the parent artery and delayed contrast medium outflow as characteristic findings of ruptured BBAs may improve the diagnosis of these uncommon aneurysms, which remains challenging in practice.