Magnetic resonance signal intensity and volume changes after endovascular treatment of intracranial aneurysms causing mass effect

Abstract

To determine when and how intracranial aneurysms causing mass effect change following endovascular treatment, we used MRI to assess patients for 2-3 years after the interventional procedure. Nine patients who had aneurysms compressing the surrounding structures underwent endovascular treatment. Proximal occlusion of the parent artery was performed in seven cases, and in two the aneurysm was embolised with microcoils. After embolisation, signal intensity within aneurysms tended to be high on both T1- and T2-weighted images. When there was rapid reduction in size high-signal zones within aneurysms became isointense or gave low signal on T1-weighted images. On T2-weighted images, isointense or low-signal foci appeared within high-signal areas in the aneurysm, giving mixed intensity. In typical cases, the mean volume of the aneurysm fell to approximately 30% of its initial value 2-12 months after treatment. After this, no additional reduction was observed. The aneurysms which showed little signal intensity change tended to shrink more slowly and to a lesser degree than the more typical cases. Aneurysms which gave high signal on both T1- and T2-weighted images early following embolisation shrank more quickly than those showing little signal change.

Clinical and Angiographic Outcome of Endovascular and Conservative Treatment for Giant Cavernous Carotid Artery Aneurysms

“…The outcome of endovascular treatment of giant CCAAs is promising. tial volume after 18 months of endosaccular coiling has been reported 27 . Gruber et al 28 reported that 45.5% of patients with symptoms of neural compression improved after endosaccular embolization of giant and very large aneurysms.…”

A single-centre experience and follow-up of patients with endovascular coiling of large and giant intracranial aneurysms with parent artery preservation

“…19 Shrinkage of approximately 57% of initial volume after 18 months of endosaccular coiling has also been reported. 20 Based on these results, mass effect symptoms will probably improve with the shrinkage of aneurysms after embolization. In our series, 69% of our patients presenting with symptoms of …”

Regrowth and Fatal Rerupture Despite Proximal Occlusion After Coil Embolization of a Ruptured Large Basilar Bifurcation Aneurysm-Case Report-

“…5,6) Additional endosaccular coil placement in the recanalized aneurysm should not be performed because of the risk of worsening the mass effect on the brainstem. 6,10) Neural compression due to GDCs in combination with the``water-hammer'' effect from the parent artery blood flow may have caused the neurological deterioration and progressive midbrain edema in our patient. 3) Worsening mass effect resulting from a coilthrombus complex may be successfully treated by BA occlusion.…”