**4. Application of 3D ultrasound reconstruction in the medical visualization**

The improvement of data acquisition methods, 3D reconstruction algorithms, volume visualizations, and hardware capabilities has greatly increased the feasibility of 3D ultrasound imaging in clinical application. Hence, the 3D ultrasound imaging has become more relevant in the medical field due to the increase in flexibility, efficiency, and real time applicability. In this section, the clinical application of 3D ultrasound reconstruction is discussed.

The 3D ultrasound imaging used in obstetrics brings two main advantages. Firstly, 3D ultrasound imaging can be used to determine the number of fetuses, fetus' surface feature, and placenta location [41]. The volume rendering can distinguish between tissue and surrounding amniotic fluids very well, and hence it is suitable to view 3D

**87**

**5. Conclusions**

**Figure 13.**

cardiology, and scoliosis assessment.

*A Survey on 3D Ultrasound Reconstruction Techniques DOI: http://dx.doi.org/10.5772/intechopen.81628*

method to get the surface of the blood vessel [12].

ultrasound fetal image for the physicians to examine the fetal presentation, as well as for the parents to see the fetus' face [1, 32]. It also can reduce the repeatability of physicians to relocate the placenta location and reduce mental workload to mentally construct the 2D ultrasound images into volumetric view. The second advantage is 3D ultrasound imaging that can assist in the accurate volume measurement of fetal size. Based on the World Health Organization (WHO) [41], the physicians need to measure the femur length, abdominal circumference, biparietal diameter, and head circumference, in order to determine whether the fetal is oversized or undersized. In cardiology, 3D ultrasound imaging can help to identify the plague in blood vessel, such as atherosclerotic stenosis. This can be achieved using segmentation

*The schematic diagram for the assessment of scoliosis using 3D ultrasound imaging system [31].*

Besides that, the 3D ultrasound imaging also proved to be effective in the assessment of scoliosis [31, 42]. Due to the need to follow up treatment frequently during the early stage, frequent X-ray examination is harmful for the young patient. Hence, 3D ultrasound reconstruction can help in scoliosis examination as ultrasound has less radiation generation and nontraumatic to the subject. The flexibility of ultrasound also allows the subject to be scanned in standing posture, which is more accurate to measure the spinal curvature angle as shown in **Figure 13**.

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,

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 *A Survey on 3D Ultrasound Reconstruction Techniques DOI: http://dx.doi.org/10.5772/intechopen.81628*

**Figure 13.**

*Artificial Intelligence - Applications in Medicine and Biology*

contained in a cube and are represented as binary number. Due to the fact that some of the cases are the inverse or symmetry of each other, the 256 cases are reduced into 15 cases with unique pattern configuration [33] and are put in a lookup table.

The marching cubes algorithm has been implemented in the 3D reconstruction of medical data, such as in medical imaging reconstruction and creating a 3D contour of a mathematical scalar field [40] and in CT reconstruction [24]. Because of the utilization of lookup table, the marching cubes algorithm is fast and simple to use. It is also capable to take full advantage of the graphical processing unit (GPU)

However, the original marching cubes algorithm suffers from the connectivity problems between triangle of adjacent cubes also known as the "hole problem" [40], which will cause the reconstruction result to be not smooth. **Figure 12** shows the "hole problem" found in the conventional marching cubes algorithm. In order to solve this issue, the efforts have been made by the past researchers, such as modifying the lookup table, extending the look-up table, etc. In [40] introduced the 21 unique pattern configurations that will always ensure the triangles of adjacent cubes

By the comparison, Wan et al. [14] found out that the marching cubes algorithm can produce sharper 3D ultrasound reconstruction image when compared with the contour filtering algorithm. Besides that, the result using marching cubes algorithm is easier to detect the edges and inner part of the ROI. However, the conventional marching cubes algorithm can generate a very large number of triangles for the 3D visualization [38]. In summary, marching cubes algorithm trades off speed for higher level of detail, while contour filtering sacrifices some details for computa-

**4. Application of 3D ultrasound reconstruction in the medical** 

The improvement of data acquisition methods, 3D reconstruction algorithms, volume visualizations, and hardware capabilities has greatly increased the feasibility of 3D ultrasound imaging in clinical application. Hence, the 3D ultrasound imaging has become more relevant in the medical field due to the increase in flexibility, efficiency, and real time applicability. In this section, the clinical application

The 3D ultrasound imaging used in obstetrics brings two main advantages. Firstly, 3D ultrasound imaging can be used to determine the number of fetuses, fetus' surface feature, and placenta location [41]. The volume rendering can distinguish between tissue and surrounding amniotic fluids very well, and hence it is suitable to view 3D

The 15 unique pattern configurations are as shown in **Figure 11**.

acceleration function to create good 3D reconstruction result [24].

will connect to each other.

tional speed.

**Figure 12.**

*The "hole problem" [40].*

**visualization**

of 3D ultrasound reconstruction is discussed.

**86**

*The schematic diagram for the assessment of scoliosis using 3D ultrasound imaging system [31].*

ultrasound fetal image for the physicians to examine the fetal presentation, as well as for the parents to see the fetus' face [1, 32]. It also can reduce the repeatability of physicians to relocate the placenta location and reduce mental workload to mentally construct the 2D ultrasound images into volumetric view. The second advantage is 3D ultrasound imaging that can assist in the accurate volume measurement of fetal size. Based on the World Health Organization (WHO) [41], the physicians need to measure the femur length, abdominal circumference, biparietal diameter, and head circumference, in order to determine whether the fetal is oversized or undersized.

In cardiology, 3D ultrasound imaging can help to identify the plague in blood vessel, such as atherosclerotic stenosis. This can be achieved using segmentation method to get the surface of the blood vessel [12].

Besides that, the 3D ultrasound imaging also proved to be effective in the assessment of scoliosis [31, 42]. Due to the need to follow up treatment frequently during the early stage, frequent X-ray examination is harmful for the young patient. Hence, 3D ultrasound reconstruction can help in scoliosis examination as ultrasound has less radiation generation and nontraumatic to the subject. The flexibility of ultrasound also allows the subject to be scanned in standing posture, which is more accurate to measure the spinal curvature angle as shown in **Figure 13**.
