Spatiotemporal Image Correlation (STIC)–Assisted Prenatal Ultrasound Diagnosis of Complex intracranial arteriovenous malformations: A Case ReportKe-xiong Niu, Tiantian Feng, Wen-dong Zhang, Tian-gang Li1Department of Ultrasound Diagnosis, Gansu Provincial Maternity and Child-care Hospital(Gansu Provincial Central Hospital）,Lanzhou, Gansu Province, P. R. China*Corresponding Author: Dr. Tiangang LiDepartment of Ultrasound Diagnosis, Gansu Provincial Maternity and Child-care Hospital(Gansu Provincial Central Hospital）,Lanzhou, Gansu Province, P. R. ChinaTelephone No.: +86-0931-2336818;mail: litiangang1981@126.comAbstractBackground: Fetal intracranial arteriovenous malformations (AVMs) are rare, complex vascular anomalies that present significant diagnostic challenges and can result in severe fetal complications, including cardiomegaly, hydrops fetalis, or intrauterine demise. Spatiotemporal image correlation (STIC) is an advanced ultrasound technique that allows for three-dimensional reconstruction of dynamic vascular structures, potentially improving the diagnosis of complex intracranial AVMs.Objective: This case report aims to illustrate the use of STIC-assisted prenatal ultrasound for diagnosing a complex fetal intracranial AVM, a condition not typically assessed using this technology.Case: A 25-year-old gravida 3, para 2 woman at 26 weeks’ gestation was referred for evaluation of abnormal intracranial vascular flow detected on routine ultrasound. Conventional imaging identified high-flow vascular signals, and STIC was used to visualize the complex vascular anatomy. The STIC volume datasets revealed a shunting channel between the posterior cerebral arteries and the straight sinus, as well as dilated transverse sinuses with arterialized venous waveforms. These findings were consistent with a complex fetal intracranial AVM.Results: STIC provided a time-resolved three-dimensional view of the lesion, enhancing the understanding of its anatomical and hemodynamic features. Multidisciplinary consultation based on STIC findings led to a shared decision regarding pregnancy termination after discussing the high risk of fetal decompensation and adverse outcomes.Conclusion: This case demonstrates that STIC can effectively delineate complex vascular structures in cases of fetal intracranial AVMs, providing valuable insights when conventional ultrasound or MRI is insufficient. STIC enhances diagnostic confidence, facilitates multidisciplinary decision-making, and supports prenatal counseling, especially in resource-limited settings. The integration of STIC into the prenatal evaluation of rare cerebrovascular anomalies may improve risk stratification and management decisions, ultimately influencing fetal outcomes.