case_images: PMC10773819_01
case_images: (A) DWI showing acute infarct lesion in the anterior segment of the left frontal hemi-oval center. (B) MRA showing aneurysm of the left MCA-M1 bifurcation anterior segment (white arrow) and MCA bifurcation showing a defect (red arrow). (C,D) CTA and DSA (orthostatic), aneurysm of the anterior segment of the M1 bifurcation of the left MCA (white arrow), MCA bifurcation aneurysm (red arrow). (E) DSA (lateral), aneurysm of the anterior segment of the M1 bifurcation of the left MCA (white arrow). (F) Preoperative surgical simulation showing aneurysm of the left MCA-M1 bifurcation anterior segment (white arrow), showing aneurysm of the left MCA bifurcation (red arrow). (G) Presence of an intact vessel branch in the M1 bifurcation anterior segment with significant atherosclerosis (black arrow) and aneurysm of the left MCA bifurcation (red arrow). (H) The left MCA-M1 bifurcation anterior segment trunk with marked atherosclerosis (black arrow), the branch vessel initiation segment there, which is a false positive aneurysm, shown by cerebrovascular imaging (white arrow).
case_images: fneur-14-1327878-g001.jpg
case_images: PMC10773819_01_fneur-14-1327878-g001.jpg
case_images: fig1
case_images: Diffusion-weighted imaging (DWI) revealed a subacute infarct lesion in the left frontal lobe (Figure 1A). M1 bifurcation of the left MCA, approximately 3.6 mm x 4.2 mm and a cystic irregular aneurysm in the MCA bifurcation, approximately 4.7 x 4.8 mm (Figure 1C). Magnetic resonance angiography (MRA), DSA (Figures 1D,E), and CTA findings were consistent, but the MCA bifurcation showed a defect in the MRA (Figure 1B). Considering that the patient had two aneurysms in the MCA, especially the risk of rupture of the cystic irregular aneurysm in the MCA bifurcation, a craniotomy was performed to clip the aneurysms. The 3Dslicer and Freesurfer software were used to simulate the surgical approach before the operation to clearly show the location and morphology of the abovementioned two aneurysms (Figure 1F). During surgery, after separating the lateral fissure vein, the MCA bifurcation aneurysm was exposed and clipped (Figure 1G). We continued to investigate along the posterior part of the M1 bifurcation and found a branch of the M1 bifurcation with an intact vessel in the anterior part of the M1 bifurcation, which showed obvious atherosclerotic changes, and the beginning of the vessel here was misdiagnosed as an aneurysm before surgery, which was very confusing (Figures 1G,H).