What Is 4D Ultrasonography?

In the medical field, 4D imagery refers to the concept of adding time to a three-dimensional image, that is, a dynamic stereoscopic image. The concept is different from the 4D imaging technology discussed in 4D cinema.

In the medical field, 4D imagery refers to the concept of adding time to a three-dimensional image, that is, a dynamic stereoscopic image. The concept is different from the 4D imaging technology discussed in 4D cinema.

Chinese name

4D image

Foreign name

4Dimaging

4D 4D image 4D ultrasound image

Although efficient three-dimensional and four-dimensional (3D / 4D) ultrasound imaging technology has been applied in the medical field for many years, it has not yet been popularized in routine clinical practice. Until recently, the clinical need for 4D technology remained low. Clinicians have not yet created a demand for 4D technology due to doubts about its clinical effect, so the hardware has not been upgraded with software ^[1] .

Physicians need ultrasound images to provide more precise information, and 4D ultrasound images can play this important role because 2D examination may not be able to obtain more complete anatomical data, and 4D ultrasound images reduce this risk. With 4D technology, only one scan is needed to provide complete anatomical data for multiple clinical applications. As clinical evidence gradually proves that the quality of 4D technology is reliable, clinicians will be more likely to adopt it.

Generally speaking, radiological stakeholders tend to be conservative and require extensive research before widespread acceptance of new clinical practice. For many years, 4D technology has been undergoing clinical trials. Recently, clinical evidence has been obtained that the fact that stereo information will not omit any information, ensures the collection and processing of all data, and ultimately achieves faster and more accurate diagnosis.

For example, when 4D image enhancement is applied to stereoscopic scanning, 4D fetal ultrasounds show excellent diagnostic capabilities for subtle fetal brain defects and other fetal malformations. In particular, according to Professor Anders Selbing's research, it is possible to better observe the structure of the near field of the fetal brain behind the skull through 4D imaging.

In addition, at the annual meeting of the International Association of Obstetricians and Gynecologists (ISUOG), Professor Boris Tutschek also presented the advantages and prerequisites of applying stereo ultrasound to fetal brain research. Professor Tutschek concluded: "4D technology can achieve ideal inspection settings, research on the relationship between each point in the brain in two or three (orthogonal) planes", and "can realize tomography (and MR and CT are comparable). In addition, by analyzing the characteristics of adjacent voxels, 4D image enhancement is achieved on the basis of 3D acquisition.

4D imaging risk

Since two-dimensional technology has been very successful so far, radiologists are generally satisfied with 2D ultrasound technology. In addition, they are not sure whether the advantages of applying 3D / 4D technology outweigh the disadvantages. At present, 3D / 4D technology can already be used in daily experiments. The real risk is that clinicians may miss some information when using 2D technology. Studies by Goldberg, Forsberg, and Lev-Toaff of Thomas Jefferson University have shown that 3D acquisition and 3D image enhancement have made significant progress statistically.

3D / 4D technology can more clearly display the size, position, shape and morphology of organs and lesions, and outline their outlines, thereby improving diagnosis and treatment. Dr. Benacerraf said: "Stereo ultrasound contains all available information, we can display images in any plane." With adaptive 3D image enhancement, we can further enhance the information in stereo ultrasound. 3D ultrasound recognition, positioning and stereo quantification have improved diagnostic quality and measurement accuracy, which is beyond the reach of 2D ultrasound. As Dr. Benacerraf puts it, "We are just beginning to explore the way information is displayed."

With 4D ultrasound images, the true position and orientation of the organs and deep embedded structures can be seen. Significant clinical benefits enable clinicians to obtain more accurate information faster. Professor Tutschek said: "4D technology can realize the ideal inspection environment, and the analysis and research of the relationship between each point in two or three orthogonal planes ^[2] ."

Most radiologists have been trained in 2D technology, and due to the lack of clinical evidence of 3D / 4D in the past, this has biased clinicians and led to a lower need for technical improvement. However, through 3D acquisition, the entire anatomical data can be obtained in one scan, and it can meet most clinical applications. This helps to achieve faster diagnosis and stimulates the needs of the application.

4D imaging hardware upgrade

Graphics processors (also known as GPUs) are not only increasingly used in the video game industry, but they can also replace or cooperate with the CPU for general-purpose computing. With the rapid development of GPU technology and the emergence of standard programming languages, the potential of 3D / 4D acquisition and 3D image enhancement software can be fully exploited ^[3] .

The rapid development of powerful and inexpensive hardware and the increasing demand of clinicians will be a strong driving factor for OEMs to invest in powerful 3D technology. OEMs can easily upgrade to 3D / 4D ultrasound probes to match 3D / 4D ultrasound imaging software.

By combining with the right software, current software can provide advanced functions cost-effectively, and previously acquiring these functions required the purchase of expensive dedicated hardware. For example, ultrasound scan conversion was originally a process that was done entirely in hardware. This process can now be done with advanced image processing software.

Obstetrics and gynecology is the best clinical application of 3D / 4D technology, which can bring the most reliable clinical benefits. However, other clinical applications, such as diagnostics in general radiology and urology, have increasing demand for 3D acquisition, so the application of 3D technology has also increased. As long as the needs of clinicians continue to grow, OEMs will have to invest in hardware capable of supporting 3D / 4D imaging ^[4] .