case_images: PMC10629289_01
case_images: Initial magnetic resonance angiography at presentation. (a) Source imaging, (b) maximum intensity projection showed an enlarged middle cerebral artery, (c, d) 10 days after the onset of the headache, these images showed enlargement of the M1 segment, (e) axial T1-weighted black-blood imaging, and (f) multiplanar imaging showed a double lumen (arrows).
case_images: SNI-14-375-g001.jpg
case_images: PMC10629289_01_SNI-14-375-g001.jpg
case_images: F1
case_images: He was referred to our department because of a dissecting cerebral aneurysm in the right M1 segment of the MCA [Figures 1a and b]. M1 in Figures 1a and b, had a headache and decided to follow-up for a short period of time given the possibility of dissection. Magnetic resonance imaging performed 10 days after headache onset revealed enlargement of the dissecting cerebral aneurysm within a short time [Figures 1c and d]. T1-weighted black-blood imaging showed a double lumen of the MCA [Figures 1e and f], suggesting a dissecting aneurysm.
case_images: Right internal carotid artery angiograms and three-dimensional digital subtraction angiograms showed a dissecting cerebral aneurysm of the M1 segment. (a and b) Anteroposterior view and (c and d) lateral view. Note that the lenticulostriate artery originates in the dissection area.
case_images: SNI-14-375-g002.jpg
case_images: PMC10629289_01_SNI-14-375-g002.jpg
case_images: F2
case_images: Digital subtraction angiography (DSA) performed 13 days after onset showed a 12-mm x 8-mm dissecting cerebral aneurysm in the right M1 segment of the MCA [Figures 2a-d].
case_images: Right internal carotid artery angiograms obtained during treatment.(a-c)Anterior views, (d) anterior views of conbeam computed tomography (CT) and (e-g) lateral views. The middle columns show post stenting with coils, and the right columns show nonsubtracted views.
case_images: SNI-14-375-g003.jpg
case_images: PMC10629289_01_SNI-14-375-g003.jpg
case_images: F3
case_images: Two detachable coils (iED  3-5 mm x 20 cm, i-ED  3-5 mm x 15 cm; Kaneka Corp., Osaka, Japan) were inserted into the aneurysm [Figures 3a-g].
case_images: (a and b) Postoperative diffusion-weighted imaging revealed sporadic areas of high signal intensity in the right cerebral hemisphere, (c and d) digital subtraction angiograms obtained 3 days after treatment showed complete occlusion of the dissecting lumen and good remodeling of the M1 segment. (e and f) Four-month follow-up angiograms showed complete obliteration of the dissecting aneurysm with preservation of the M1 segment.
case_images: SNI-14-375-g004.jpg
case_images: PMC10629289_01_SNI-14-375-g004.jpg
case_images: F4
case_images: On the 1st postoperative day, diffusion-weighted imaging revealed sporadic high-intensity signals in the right cerebral hemisphere [Figures 4a and b]. DSA performed 3 days after the procedure showed no in-stent thrombosis and good remodeling of the M1 segment without blood flow into the aneurysm [Figures 4c and d]. Four months later, DSA showed good patency of the M1 segment with no recurrence of the dissecting aneurysm [Figures 4e and f].