case_images: PMC4901822_01
case_images: Conformal radiotherapy plan showing the dose distribution where the planning treatment volume is the shaded red contour, and the isodoses are given as a percentage of 60 Gy
case_images: SNI-7-387-g001.jpg
case_images: PMC4901822_01_SNI-7-387-g001.jpg
case_images: F1
case_images: The first phase delivered 54 Gy to the whole planning treatment volume in 27 fractions [Figure 1].
case_images: Magnetic resonance imaging brain performed a few days before aneurysm presentation. It shows small intensely enhancing area closely related to left insula showing unusual peripheral ring of enhancement (top right and bottom left) and strikingly low signal on T2-weighted imaging (bottom right). This was initially thought to be tumor progression but later retrospectively recognized as corresponding to the fusiform aneurysm
case_images: SNI-7-387-g002.jpg
case_images: PMC4901822_01_SNI-7-387-g002.jpg
case_images: F2
case_images: A routine follow-up MRI in April 2012 showed an entirely new area of enhancement in the left Sylvian cortex adjacent to two prominent vessels thought initially to be further tumor progression [Figure 2].
case_images: Computed tomography angiogram (left) and corresponding digital subtraction angiogram (right) images confirming the fairly long irregular fusiform dilatation (indicated by the white arrows)
case_images: SNI-7-387-g003.jpg
case_images: PMC4901822_01_SNI-7-387-g003.jpg
case_images: F3
case_images: CT angiography [Figure 3] showed a very irregular fusiform aneurysm of a Sylvian branch (supramarginal) of the left middle cerebral artery (MCA) with the hyperdensity thought to be either intra-aneurysmal thrombus or mural/perimural hemorrhage. Digital subtraction angiogram confirmed the large, irregular fusiform aneurysm involving the posterior Sylvian branch of the left MCA [Figure 3].
case_images: Magnetic resonance imaging brain performed after patient presented with symptoms related to the aneurysm. T2-weighted fast spin echo (top left), gradient echo (top right), T1 with gadolinium (bottom left), and axial flair (bottom right) images confirmed the fusiform aneurysm with a cap of thrombus around its distal part, likely to be either intraluminal or intramural thrombus. There was no evidence of extraluminal hemorrhage
case_images: SNI-7-387-g004.jpg
case_images: PMC4901822_01_SNI-7-387-g004.jpg
case_images: F4
case_images: There was no clear evidence of extraluminal hemorrhage [Figure 4].
case_images: Awake catheter angiogram/digital subtraction angiogram performed during trial balloon occlusion showing the fusiform aneurysm (left) and loss of flow in the middle cerebral artery branch when the balloon microcatheter was deployed even without inflation resulting in profound dysphasia (right)
case_images: SNI-7-387-g005.jpg
case_images: PMC4901822_01_SNI-7-387-g005.jpg
case_images: F5
case_images: Placement of a balloon microcatheter, without inflation, into the origin of the MCA branch was sufficient to arrest flow [Figure 5].
case_images: Initial magnetic resonance angiogram (left) showing the fusiform aneurysm. Three-month follow-up magnetic resonance angiogram (right) showing partial thrombosis of the fusiform aneurysm
case_images: SNI-7-387-g006.jpg
case_images: PMC4901822_01_SNI-7-387-g006.jpg
case_images: F6
case_images: MRI, 3 months later [Figure 6], revealed narrowing and partial thrombosis of the aneurysmal segment and the patient remained asymptomatic.