Vessel Wall Imaging After Subarachnoid Hemorrhage in Patients with Multiple Intracranial Aneurysms: A Cautionary Case

Background: Almost 30% of patients with subarachnoid hemorrhage (SAH) are found to have multiple aneurysms. This can potentially present a serious management dilemma when planning treatment. Magnetic resonance imaging vessel wall imaging (VWI) has been proposed as a reliable technique in differentiating between ruptured and unruptured aneurysms in patients with multiple intracranial aneurysms who present with SAH. Expert consensus now supports this as a possible use for the technique.

Case description: Here we present a patient presenting a particular clinical dilemma with SAH and a left third nerve palsy and transient speech disturbance who had circumferential enhancement in the left larger 3.5-mm irregular middle cerebral artery aneurysm and no detectable enhancement in what was angiographically either a 1.5-mm smooth noncompressive left posterior communicating artery aneurysm or infundibulum, but was proved at surgery to be the culprit aneurysm.

Conclusion: Although a case of concurrent false positive and false negative in the same patient has not previously been reported, the positive predictive value of VWI for rupture status is known to be much lower than its negative predictive value, and a case like this might be expected to occur in 0.6% of patients. Therefore, whereas VWI is a valuable tool, it should be used in conjunction with, and not in lieu of, traditional indicators of aneurysm rupture.