PMC10159299_01
(a) Computed tomography (CT) on admission. Magnetic resonance imaging (b and c) 3 days and (d-f) 93 days after onset (a) CT: Hematoma in the left primary motor cortex. (b) Arterial spin labeling (ASL): No obvious high signal around the hematoma. (c) Magnetic resonance angiography (MRA): No abnormal vessel around the hematoma (d) Flow-attenuated inverted recovery: Shrinkage of hematoma. (e) ASL: High focal signal on the convexity of the left frontal lobe and suprasagittal sinus (white arrow), which was not seen in previous ASL. (f) MRA showing a newly depicted vessel (white arrowhead) flowing in the direction of the hematoma.
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F1
On admission, computed tomography (CT) revealed left frontal lobe hemorrhage [Figure 1a]. ASL (post-labeling delay: 1200 ms) [Figure 1b] and magnetic resonance angiography (MRA) [Figure 1c] conducted 3 days after onset did not show abnormal vascular structures. Although slight upper-extremity paralysis persisted, activities of daily living were performed independently. Fluid-attenuated inversion recovery revealed shrinkage of the hemorrhage [Figure 1d]. The ASL showed a high focal signal on the cortical vein in the left frontal lobe and superior sagittal sinus (SSS) [Figure 1e], and MRA revealed a thicker left posterior internal frontal artery adjacent to the hematoma [Figure 1f], which was not seen in the first ASL and MRA.
Digital subtraction angiography (DSA). (a) 1 day after onset (b) 93 days after onset (a) abnormal vessel and early venous filling were not observed. (b) Micro-arteriovenous malformation (AVM) (white arrowhead) was observed, which was not seen on DSA 5 days after onset. (c) Enlarged micro-AVM image. The micro-AVM comprised a 6 mm nidus with a single feeding of a branch of the left anterior parietal artery. A draining vein arose from the posterior side of the nidus and flowed toward the superior sagittal sinus through the cortex vein on the frontal lobe.
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F2
Highly suspecting AVM, we performed a second DSA 98 days after the onset and detected micro-AVM in the left frontal lobe, which was not observed in the initial DSA [Figures 2a-c].