P17.37.a Preliminary Experience of High Resolution Transcranial Ultrasound in Intracranial Tumor

BACKGROUND Preoperative imaging modalities such as CT/MRI are indispensable in intracranial tumor management, yet they cannot provide real-time updates and require large, specialized equipment. Transcranial ultrasound (TCUS) enables non-invasive, real-time bedside imaging. However, conventional TCUS is restricted to evaluating major intracranial vessels and midline structures (e.g., midbrain), resulting in limited clinical utility. The advent of high-resolution transcranial ultrasound (HR-TCUS) now allows detailed sonographic evaluation of intracranial tumors. This study aims to report preliminary clinical experiences with high-resolution transcranial imaging in the evaluation of intracranial tumors. MATERIAL AND METHODS A prospective cohort of 16 patients with intracranial tumors (8 skull base lesions, including meningiomas and pituitary adenomas) underwent HR-TCUS (Krinwave Rocvue T7®) via bilateral temporal bone windows. We applied an ultrasound visibility classification system to assess trancranial ultrasound images based on tumor visibility and boundary (Type 0: invisible; Type 1: difficult to visualize and no clear border; Type 2: clearly identifiable but no clear border; Type 3: clearly identifiable with clear border). Vascular displacement/encasement (e.g., middle cerebral artery) was also assessed using doppler ultrasonography. HR-TCUS findings were compared with preoperative MRI/MRA/CTA. RESULTS Three patients were excluded due to poor acoustic window quality. Data from 13 patients (6 females) were finally analyzed, including: low-grade glioma (n=1), high-grade gliomas (n=3), brain metastasis (n=2), sphenoid wing meningiomas (n=2), convexity meningiomas (n=3), and pituitary adenomas (n=2). HR-TCUS visibility classification results: low-grade glioma: type 0 (n=1), high-grade gliomas: type 2 (n=1) and type 3 (n=2), brain metastases: type 2 (n=2), sphenoid wing meningiomas: type 2 (n=2), convexity meningiomas type 1 (n=1) and type 2 (n=2), and pituitary adenomas: type 1 (n=2). Vascular encasement/displacement was observed in sphenoid wing meningiomas and pituitary adenomas, consistent with preoperative MRA/CTA findings. CONCLUSION This preliminary study demonstrates that high-resolution transcranial ultrasound (HR-TCUS) is a feasible and valuable adjunct for preoperative evaluation of intracranial tumors, particularly in assessing skull base lesions and their complex vascular relationships.