Magnetic resonance imaging (MRI), including T2*-weighted gradient-echo and diffusion-weighted susceptibility imaging (DWI) sequences, has become a valuable clue for the diagnosis of intracranial dissecting aneurysms and their acute complications.
A 16-year-old patient was initially seen with sudden-onset occipital headache and vomiting. Clinical examination showed left limb ataxia and stiffness of the neck. Magnetic resonance imaging was performed on a Philips 1.5-T MRI unit. T2*-weighted gradient-echo and DWI sequences were obtained using the following parameters: T2*-weighted gradient-echo sequence, repetition time = 600 to 800 milliseconds; echo time = 30 to 50 milliseconds; 22 sections; section thickness, 5 mm; field of view, 240 mm; flip angle, 10° to 20° and DWI sequence, repetition time = 3480 milliseconds; echo time = 74 milliseconds; 22 sections; section thickness, 5 mm; matrix size, 90 × 256. Magnetic resonance imaging showed a giant fusiform dilatation of the left vertebral artery. The largest diameter was 30 mm. T2* susceptibility-weighted imaging sequences showed a large intravascular clot with low signal (Figure, A) and old microbleeds within the pons (Figure, B). Diffusion-weighted imaging showed a left posterior inferior cerebellar artery infarct (Figure, C). Twenty-four hours later the patient suddenly became comatose. Computed tomography revealed a widespread subarachnoid hemorrhage. The patient died 1 week later.
Androdias G, Hermier M, Turjman F, Honnorat J, Nighoghossian N. Simultaneous Subarachnoid Hemorrhage and Cerebellar Infarct Revealing Vertebral Artery AneurysmAcute Magnetic Resonance Imaging Assessment. Arch Neurol. 2005;62(7):1158. doi:10.1001/archneur.62.7.1158