发表机构
Georgia Institute of Technology（佐治亚理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
提出一种无MRI的CT到超声颅骨配准框架，利用混合CMUT tFUS阵列结合治疗与成像，融合配准达到0.271毫米位移误差，支持全超声方法。
AI 中文摘要
准确的颅骨到阵列配准对于经颅聚焦超声（tFUS）至关重要，因为从CT获得的颅骨模型必须与物理阵列坐标系对齐，以支持患者特异性像差校正。当前的工作流程通常使用MRI和/或外部跟踪来建立这种空间关系，从而增加了成像基础设施和坐标变换到治疗工作流程中。在此，我们描述了一种使用混合半球形CMUT tFUS阵列的无MRI的CT到超声配准框架，该阵列结合了稀疏治疗阵列与集成的CMUT US-Cross成像阵列。治疗阵列提供颅骨位置的脉冲回波测量，而US-Cross阵列提供颅骨表面的局部高分辨率图像。该方法使用从CT导出的外皮质颅骨表面进行评估，跨越25个姿态矩阵，颅骨与阵列中心之间有10毫米的横向偏移和±5度的角度扰动。应用五个随机径向噪声种子到治疗脉冲回波测量，以模拟测量或元件放置误差，每个噪声和活动元件设置产生125个姿态种子实现。US-Cross成像特征使用Field II和延迟乘加平面波复合生成。评估了四种配准模式：仅治疗、仅超声成像、顺序和融合配准。融合配准取得了最佳整体性能，中位总位移误差为0.271毫米[0.169-0.420]，中位旋转误差为0.904度[0.432-1.639]。这些结果支持使用混合CMUT tFUS阵列的全超声方法进行无MRI的CT-US颅骨配准。
英文摘要
Accurate skull-to-array registration is essential for transcranial focused ultrasound (tFUS) because CT-derived skull models must be aligned with the physical-array coordinate system to support patient-specific aberration correction. Current workflows typically use MRI and/or external tracking to establish this spatial relationship, adding imaging infrastructure and coordinate transformations to the treatment workflow. Here, we describe an MRI-free CT-to-ultrasound registration framework using a hybrid hemispherical CMUT tFUS array that combines a sparse therapeutic array with an integrated CMUT US-Cross imaging array. The therapeutic array provides pulse-echo measurements of skull location, while the US-Cross array provides local high-resolution images of the skull surface. The approach was evaluated using a CT-derived outer cortical skull surface across a 25-pose matrix with 10-mm lateral offsets between the skull and array centers and +/-5 degree angular perturbations. Five randomized radial-noise seeds were applied to therapeutic pulse-echo measurements to model measurement or element-placement errors, yielding 125 pose-seed realizations per noise and active-element setting. US-Cross imaging features were generated using Field II and delay-multiply-and-sum plane-wave compounding. Four registration modes were evaluated: Therapeutic only, US-imaging only, Sequential, and Fused registration. Fused registration yielded the best overall performance, with a median total displacement error of 0.271 mm [0.169-0.420] and a median rotation error of 0.904 degrees [0.432-1.639]. These results support an all-ultrasound-based approach using a hybrid CMUT tFUS array for MRI-free CT-US skull registration.
Comments15 pages document including 3 pages supplement
