Zou Jing, Qin Jing
Centre for Smart Health, School of Nursing, the Hong Kong Polytechnic University, Hong Kong, China.
Vis Comput Ind Biomed Art. 2024 Oct 25;7(1):25. doi: 10.1186/s42492-024-00177-4.
Three-dimensional (3D) fetal ultrasound has been widely used in prenatal examinations. Realistic and real-time volumetric ultrasound volume rendering can enhance the effectiveness of diagnoses and assist obstetricians and pregnant mothers in communicating. However, this remains a challenging task because (1) there is a large amount of speckle noise in ultrasound images and (2) ultrasound images usually have low contrasts, making it difficult to distinguish different tissues and organs. However, traditional local-illumination-based methods do not achieve satisfactory results. This real-time requirement makes the task increasingly challenging. This study presents a novel real-time volume-rendering method equipped with a global illumination model for 3D fetal ultrasound visualization. This method can render direct illumination and indirect illumination separately by calculating single scattering and multiple scattering radiances, respectively. The indirect illumination effect was simulated using volumetric photon mapping. Calculating each photon's brightness is proposed using a novel screen-space destiny estimation to avoid complicated storage structures and accelerate computation. This study proposes a high dynamic range approach to address the issue of fetal skin with a dynamic range exceeding that of the display device. Experiments show that our technology, compared to conventional methodologies, can generate realistic rendering results with far more depth information.
三维（3D）胎儿超声已广泛应用于产前检查。逼真且实时的容积超声容积渲染可以提高诊断的有效性，并有助于产科医生与孕妇进行沟通。然而，这仍然是一项具有挑战性的任务，原因如下：（1）超声图像中存在大量斑点噪声；（2）超声图像通常对比度较低，难以区分不同的组织和器官。然而，传统的基于局部光照的方法并未取得令人满意的结果。这种实时要求使得该任务变得越来越具有挑战性。本研究提出了一种新颖的实时容积渲染方法，该方法配备了用于3D胎儿超声可视化的全局光照模型。该方法可以通过分别计算单次散射和多次散射辐射率来分别渲染直接光照和间接光照。使用容积光子映射模拟间接光照效果。提出使用一种新颖的屏幕空间命运估计来计算每个光子的亮度，以避免复杂的存储结构并加速计算。本研究提出了一种高动态范围方法来解决胎儿皮肤动态范围超过显示设备动态范围的问题。实验表明，与传统方法相比，我们的技术可以生成具有更多深度信息的逼真渲染结果。
