**5. Conclusions**

This chapter discussed the analysis on the literature of existing 3D ultrasound reconstruction method or algorithm. First, the 3D ultrasound imaging system can be classified as the 2D array scanning system, the mechanical scanning system, and the freehand scanning system. Their properties, advantages, and disadvantages are discussed. Second, the reconstruction process for the 3D ultrasound imaging system is explained. The steps required by the 3D ultrasound reconstruction are data acquisition stage, data preprocessing stage, implementing volume reconstruction method stage, and 3D visualization stage. Lastly, the advantages of 3D ultrasound reconstruction in the medical visualization are discussed, which includes obstetrics, cardiology, and scoliosis assessment.

The main limitation found in the current methods is the requirement for large computational processing power in order to visualize accurate medical data. Through the improvement of hardware capabilities such as GPU, the computational power and speed limitation can be improved. However, this presents a new problem, which is the increase in the cost of production. Therefore, we observed that the computational speed, accuracy of reconstruction, and cost-effectiveness are the challenges to be faced to provide a practicable 3D ultrasound reconstruction system.

In the future, the augmented reality (AR) medical can solve a lot of issue in ultrasonography, especially in the viewing of ultrasound image, as it can display the ultrasound image or other important information in the field of view of the physicians. This can further improve the clinician's perception toward the scanned ROI.

Furthermore, the data visualization method can also greatly improve the ultrasound perception by assigning the color to the scanned organs. This is because the current ultrasound images are black and white and are very hard to distinguish between different organs. Based on the physical properties of organs, the reflected intensity of ultrasonic wave is different for every organ. In this way, the color mapping can be used in different intensities to produce colorful ultrasound image, which represents and distinguishes every organ in the scanned region. Besides that, flow visualization can also be incorporated in the ultrasound visualization, such as different colors for different blood flow directions.
