Dome-remnant dissociation after coil embolization of a basilar tip aneurysm: serial MR cisternography, silent MRA, and computational fluid dynamics findings suggest early hemodynamic redistribution. Illustrative case.

backgroundRecurrence after coil embolization of intracranial aneurysms is commonly attributed to coil compaction or aneurysm regrowth. However, early spatial changes between the coiled dome and the remnant cavity remain poorly understood. The authors describe serial imaging findings demonstrating dome-remnant dissociation and explore their potential implications for the early detection of aneurysm recurrence. OBSERVATIONS: A large basilar tip aneurysm treated with coil embolization was followed with serial fusion imaging using MR cisternography and silent MRA. MR cisternography delineates the outer contour of the aneurysm independently of intraluminal signal, whereas silent MRA enables visualization of residual intra-aneurysmal flow within the remnant cavity after coil embolization. Over time, spatial dissociation between the coiled dome and the remnant cavity became evident despite minimal angiographic change on conventional imaging. Computational fluid dynamics suggested redistribution of intra-aneurysmal flow, with progressive migration of the inflow impingement region. LESSONS: Combined fusion imaging with MR cisternography and silent MRA enables visualization of dome-remnant dissociation that cannot be detected with conventional angiographic techniques alone. This dissociation may represent an early imaging marker of spatially asymmetric redistribution of intra-aneurysmal flow preceding aneurysm recurrence after coil embolization. https://thejns.org/doi/10.3171/CASE26217.