{"id":278,"date":"2024-01-28T22:15:26","date_gmt":"2024-01-28T22:15:26","guid":{"rendered":"https:\/\/pressbooks.palni.org\/ultrasoundphysicsanditsapplicationinmedicine\/?post_type=chapter&p=278"},"modified":"2024-03-18T23:03:13","modified_gmt":"2024-03-18T23:03:13","slug":"2d-3d-and-4d-ultrasound-imaging","status":"publish","type":"chapter","link":"https:\/\/pressbooks.palni.org\/ultrasoundphysicsanditsapplicationinmedicine\/chapter\/2d-3d-and-4d-ultrasound-imaging\/","title":{"raw":"2D, 3D, and 4D Ultrasound Imaging","rendered":"2D, 3D, and 4D Ultrasound Imaging"},"content":{"raw":"
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3.1 Learning Objectives<\/p>\r\n\r\n<\/header>\r\n

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After reviewing this chapter, you should be able to do the following:<\/p>\r\n\r\n

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  1. Define and explain the mode of operation of two-dimensional (<\/a>2D), three-dimensional (3D), and four-dimensional (4D) ultrasound imaging.<\/li>\r\n \t
  2. Compare and contrast the advantages and disadvantages of 2D, 3D, and 4D ultrasound imaging in medical applications.<\/li>\r\n \t
  3. Evaluate the diagnostic benefits of 3D\/4D ultrasound imaging over 2D imaging in different medical fields, such as obstetrics, gynecology, and cardiology.<\/li>\r\n \t
  4. Analyze the limitations of 3D\/4D ultrasound imaging in medical applications, including technical, clinical, and ethical considerations.<\/li>\r\n \t
  5. Describe the recent improvements in technology, image quality, and clinical ease of use that have contributed to the expanding applications of 3D\/4D ultrasound imaging in patient care.<\/li>\r\n \t
  6. Critically assess the current use and potential future directions of 3D\/4D ultrasound imaging in clinical practice, research, and education.<\/li>\r\n \t
  7. Discuss the ethical implications of 3D\/4D ultrasound imaging, such as fetal imaging for nonmedical purposes, and the impact of imaging on patient autonomy and decision-making.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n

    3.2 Introduction<\/h1>\r\n

    Medical ultrasound continues to make significant contributions to patient care by providing anatomical information needed by clinicians to make critical decisions. While 3D ultrasound has been commonly used in cardiology, obstetrics, and gynecology, its applications continue to expand as essential technological improvements, image quality, and clinical ease of use increase. In this section, we discuss the modes of operation of 2D, 3D, and 4D ultrasound imaging and their current diagnostic benefits and limitations in the medical field. First, we will consider the advantages of 3D\/4D over 2D imaging.<\/p>\r\n\r\n

    3.3 Using 2D Versus 3D and 4D Ultrasound<\/h1>\r\n

    Two-dimensional ultrasound is considered a standard or conventional imaging technique. In 2D scanning, a series of thin slices make up an image, and only one slice can be seen at a time.<\/p>\r\n

    Three- and four-dimensional clinical ultrasounds have been around for nearly 25 years. However, their use has lagged behind that of computerized tomography (CT) and magnetic resonance imaging (MRI) due to the difficulty in rendering the data in 3D.[footnote]Benacerraf BR. Three-dimensional fetal sonography: Use and misuse. J Ultrasound Med. 2002 Oct;21(10):1063\u20137. doi: 10.7863\/jum.2002.21.10.1063. PMID: 12369660.[\/footnote] However, ultrasound equipment\u2019s increasing computing power has helped resolve complex signal processing tasks needed to render 3D ultrasound data.<\/p>\r\n

    Three-dimensional ultrasound is based on the same principles of operation as 2D ultrasound but has an added position-sensing component to produce the effect of a 3D image, as illustrated in Figure 3-1. In 3D ultrasound imaging, echoes are used to form real-like realistic volume images.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"598\"]\"Orthogonal Figure 3-1: Orthogonal planes of the uterus.[\/caption]\r\n

    A 4D ultrasound shows 3D ultrasound images in motion. Two-dimensional ultrasound images are commonly used because they are less expensive than 3D or 4D. However, many centers now use 3D\/4D ultrasound. The most common area of use has been fetal cardiovascular scanning. The 3D\/4D technology offers real-time motion-gated cardiac scanning.<\/p>\r\n

    A 3D\/4D ultrasound offers expecting parents a memorable lifetime opportunity to see the features of their unborn babies. Figure 3-2 shows 2D grayscale and 3D colored images.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"683\"]\"2D Figure 3-2: 2D grayscale image on the left (Scan20semanas1<\/a> by Guimi licensed under CC BY-SA 2.5<\/a>) and 3D colored image on the right (4215.600x450<\/a> by Clayuyu licensed under CC BY-SA 4.0<\/a>).[\/caption]\r\n

    3.4 Accuracy and Repeatability<\/h1>\r\n

    Acquiring qualitative and quantitative sonographic volume data such as multiplanar imaging, surface and volume rendering, and semiautomated volume calculation gives 3D\/4D an added advantage over 2D imaging. Virtual planes provide extra information that cannot be viewed with a standard 2D technique.[footnote]Yagel S, Cohen SM, Shapiro I, Valsky DV. 3D and 4D ultrasound in fetal cardiac scanning: A new look at the fetal heart. Ultrasound Obstet Gynecol. 2007 Jan;29(1):81\u201395. doi: 10.1002\/uog.3912. PMID: 17200988.[\/footnote] The American Institute of Ultrasound in Medicine (AIUM) notes that the ability to take images in any plane in real time has enormous potential use in medical diagnosis.[footnote]Benacerraf BR, Benson CB, Abuhamad AZ, Copel JA, Abramowicz JS, Devore GR, Doubilet PM, Lee W, Lev-Toaff AS, Merz E, Nelson TR, O\u2019Neill MJ, Parsons AK, Platt LD, Pretorius DH, Timor-Tritsch IE. Three- and 4-dimensional ultrasound in obstetrics and gynecology: Proceedings of the American Institute of Ultrasound in Medicine Consensus Conference. J Ultrasound Med. 2005 Dec;24(12):1587\u201397. doi: 10.7863\/jum.2005.24.12.1587. PMID: 16301716.[\/footnote] Another advantage is that 3D ultrasound can provide measurements in three planes with acceptable reliability.<\/p>\r\n\r\n

    3.5 Equipment Design and Image Acquisition<\/h1>\r\n

    A 3D ultrasound uses a series of 2D images covering a volume of a particular area. This allows the images to be rotated and displayed in different orientations. When displayed in real time, or live, they form a 4D ultrasound. Volume acquisition is achieved by using an array of transducers consisting of many 2D frames, one behind the other. Automated mathematical algorithms are then used to process the volume data to produce the desired image, as illustrated in Figure 3-3.<\/p>\r\n

    The reconstruction in Figure 3-3 occurs in a matter of seconds such that the spatio-temporal imaging correlation (STIC) acquisition is completed in the presence of the patient. The STIC acquisition mode can be combined with B-mode, color, and power Doppler. From a good STIC acquisition, a sequential plane may be viewed in corresponding transverse and longitudinal planes at any time point, simultaneously.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"698\"]\"A Figure 3-3: A schematic of the formation of a 4D ultrasound image. Figure 1<\/a> by Yagel S, Cohen SM, Shapiro I, and Valsky DV licensed under CC BY 2.0<\/a>[\/caption]\r\n

    The B-flow image is a live grayscale depiction of blood flow and cardiac chambers. When applied to 3D fetal echocardiography, the B-flow image shows blood flow in the heart and great vessels in real time.[footnote]Yagel S, Cohen SM, Shapiro I, Valsky DV. 3D and 4D ultrasound in fetal cardiac scanning: A new look at the fetal heart. Ultrasound Obstet Gynecol. 2007 Jan;29(1):81\u201395. doi: 10.1002\/uog.3912. PMID: 17200988.[\/footnote]<\/p>\r\n\r\n

    3.6 Display and Analysis<\/h1>\r\n

    Four-dimensional imaging involves a 3D image moving in real time, created from a volume of data that allows the live reconstruction of images in different planes and renderings. Rendering<\/em><\/span> is taking voxel-based data and converting it into a viewable image with added depth. Three- and four-dimensional imaging function by reconstructing an image from multiple 2D planes.<\/p>\r\n\r\n

    3.7 Areas of Applications<\/h1>\r\n

    The 3D color and power Doppler ultrasound technology can be used in vascular abnormality assessments such as the fetal placental cord and pulmonary vessels. Three-dimensional ultrasound is not yet widely used in many routine medical procedures but has been widely used in gynecology, obstetrics, and biopsy.<\/p>\r\n

    In gynecology, 3D ultrasound can be used to<\/p>\r\n\r\n