Multiple antiplatelet therapy contributes to the reversible high signal spots on diffusion-weighted imaging in elective coiling of unruptured cerebral aneurysm.

INTRODUCTION: Our aim was to systematically investigate radiographic characteristics and outcome of diffusion-weighted imaging (DWI) changes in the elective coiling of unruptured cerebral aneurysm with analyzing the correlation of antiplatelet therapy (APT). METHODS: In a total of 34 consecutive patients with unruptured cerebral aneurysms initially treated by coiling without stent assist, 26 (76.5%) had DWI changes with 91 high signal spots within 24-48 h after the procedure. We recorded DWI parameters (location, volume, mean, and minimum values of the apparent diffusion coefficient: expressed as ADCAVE and ADCMIN) for each lesion, and evaluated its radiographic outcome on conventional MRI at follow-up (interval, 58.4 ± 37.2 days) in the modes of APT. RESULTS: All patients with DWI high spots had no clinical symptoms. There was a strong correlation between ADCAVE and ADCMIN (r = 0.82, p < 0.0001). The mean ADCAVE and rADCAVE were 0.74 ± 0.14 × 10(-3) mm(2)/s and 87 ± 10 %. DWI high spots were small with a mean volume of 0.13 ± 0.12 cm(3), ranging from 0.04 to 0.86 cm(3). A negative correlation was observed between the volume and values of ADCAVE (r = -0.48, p < 0.0001). The DWI volume was significantly larger in single APT than in multiple (0.15 ± 0.14 versus 0.10 ± 0.07 cm(3), p = 0.0091). The permanent signal change was more observed in single APT than in multiple (24.5% versus 5.2%, p = 0.02). CONCLUSION: DWI high spots after elective coiling were small without significant decrease of ADC, and do not correspond to brain infarction. Periprocedural use of multiple antiplatelet agents is expected to reduce the volume of thromboembolism and permanent tissue damages.