7T magnetic resonance angiographic imaging of basilar artery perforator aneurysms – initial experience of a non-invasive alternative to DSA

Background: Perforator aneurysms of the basilar artery (PABA) are rare causes of subarachnoid haemorrhage (SAH) and challenging to diagnose. We present two cases of SAH caused by PABA diagnosed by cone beam computed tomography angiography (CBCTA) and a novel non-invasive method – 7T magnetic resonance imaging (7T MRI). Methods: Two patients with SAH, diagnosed with PABA, were imaged on day 9 and 13 after onset, respectively, with CBCTA and 7T MR angiography (MRA) performed on the day after and at follow-up at 3 months. Results: All four 7T MRI examinations in the two patients were technically successful with fully diagnostic images. No endovascular treatment was performed and control with 7T MRA at 3 months showed no remaining aneurysms. Conclusion: PABA can be imaged with 7T MRI – a novel non-invasive method, allowing non-invasive follow-up to monitor this rare cause of SAH.