3D Breast Ultrasound

3D Ultrasonography in Breast Imaging

Even though 3D Ultrasonography is not new in fields like cardiology or obstetrics, it is comparatively new in the field of breast imaging. The ordinary 2D breast ultrasonography has been challenging because it is difficult to differentiate between normal or benign fibrocystic lesions and early pathologic lesions. However, with the improvement and accessibility of 3D Ultrasonography, identifying lesions from benign changes has become easier.

Advantages of 3D Ultrasonography

3D Ultrasonography offers several advantages in breast imaging:

• Improved Lesion Identification: Helps differentiate between benign and pathological lesions more effectively.
• Enhanced Screening: Studies have shown that 3D ultrasonography is better for screening young patients and those with dense breasts.

“With the improvement and accessibility of 3D Ultrasonography, identifying lesions from benign changes has become easier.”

Applications of 3D Breast Ultrasound

3D breast ultrasound can be used in various applications:

• Adjunct to Mammography: It can be used alongside plain film/computerized mammography or digital breast tomosynthesis (DBT).
• Dense Breast Tissue: Particularly useful for patients with dense breast tissue where traditional mammography may not be as effective.

3D Ultrasonography is a valuable tool in breast imaging, providing enhanced clarity and differentiation of lesions. Its ability to serve as an adjunct to traditional imaging techniques makes it a critical component in comprehensive breast cancer screening and diagnosis.

For further insights and detailed information on advanced breast imaging techniques, explore our resources at CE4RT Radiologic Technology Resources.

 

Advanced Technologies in Breast Imaging

Despite the proven effectiveness of mammography, there is a growing interest in utilizing more advanced technologies for diagnosing breast lesions, particularly in women with dense breast tissue and those at high risk for breast cancer. One significant limitation of mammography is its inability to clearly differentiate non-calcified tumors from the surrounding dense breast tissue. This limitation can be addressed by using breast ultrasound.

The Role of Breast Ultrasound

Breast ultrasound has become widely accepted as a standard diagnostic procedure for women with clinically or radiologically suspicious breast lesions. It serves as a crucial complement to mammography, especially in patients with dense breast tissue where mammography may fall short. Breast ultrasound plays a vital role in the clinical diagnosis of breast cancer by providing additional imaging clarity.

Key Advantages of Breast Ultrasound

• Identifying Lesions: Effective in identifying palpable breast lesions and suspicious findings detected on mammography.
• Cystic vs. Solid Lesions: Distinguishes between cystic (fluid-filled) and solid lesions with near-perfect accuracy.
• Non-Invasive: Safe and accessible option as it does not involve ionizing radiation.
• High-Frequency Sound Waves: Generates detailed images of breast tissue, aiding in accurate diagnoses.

“Breast ultrasound is particularly beneficial for younger women and those with dense breast tissue, where traditional mammography may not provide clear results.”

Breast Ultrasound and Advancements

Regular advances in transducer design, hardware, PCs, and signal processing have significantly enhanced the quality of ultrasound images. Breast ultrasound is utilized in various forms, with B-mode being the most common type of imaging. However, compound imaging and harmonic imaging are increasingly used to better visualize breast lesions and reduce image artifacts.

3D Ultrasonography in Breast Imaging

While 3D ultrasonography is well-established in fields like cardiology and obstetrics, it is relatively new in breast imaging:

• Traditional 2D Challenges: Differentiating between normal or benign fibrocystic lesions and early pathological lesions can be difficult with traditional 2D ultrasound.
• Advancements in 3D: 3D ultrasonography makes distinguishing between lesions and benign changes easier.
• Effective for Dense Breasts: Studies show that 3D ultrasonography is particularly effective for screening young patients and those with dense breasts.
• Adjunct to Mammography: 3D breast ultrasound can be used alongside traditional film mammography, computerized mammography, or digital breast tomosynthesis (DBT).

Procedure for 3D Breast Ultrasound

3D breast ultrasound is a sophisticated imaging technique that involves a single craniocaudal sweep from the supraclavicular region to the inframammary fold using a 15 cm transducer device. While this method provides detailed images, it does have limitations:

• Incomplete Visualization: The axillary tail and lower axilla are not fully visualized, which means a complete examination of the entire breast is not possible with this technique alone.
• Adjunct to Mammography: When used alongside mammography, 3D breast ultrasound ensures comprehensive imaging, covering the areas not fully visualized by the ultrasound alone.

Enhanced Diagnostic Accuracy

Incorporating 3D breast ultrasound with traditional mammography enhances diagnostic accuracy by providing a more comprehensive view of the breast tissue. This combined approach is particularly beneficial for women with dense breast tissue or those presenting with suspicious lesions.

“Its ability to accurately differentiate between different types of lesions and provide detailed imaging makes it a critical component of comprehensive breast health evaluation.”

Summary

While mammography remains a cornerstone in breast cancer screening, breast ultrasound, particularly 3D ultrasonography, serves as an invaluable adjunct. Its capabilities in differentiating between lesions and benign changes, along with providing detailed imaging, make it essential for comprehensive breast health evaluation.

 

Advantages of 3D Breast Ultrasonography Over 2D Ultrasonography

Limitations of 2D Ultrasonography

Screening using a conventional handheld transducer in 2D ultrasound is operator-dependent, meaning some areas of the breast may be missed during examination. Additionally, breast lesions must be quickly analyzed during the ultrasound exam, and the lack of standardization in sonographic criteria makes it difficult to perform a second evaluation on hard-copy printouts.

Advantages of 3D Ultrasonography

Three-dimensional (3D) ultrasound offers significant improvements over traditional 2D ultrasound. Here are the key advantages:

• Multiple Sectional Planes: Generates multiple sectional planes of a lesion and calculates volume, offering comprehensive visualization.
• Overcoming Limitations: Addresses operator-dependent limitations and provides standardized documentation.
• Coronal Plane Imaging: Offers a coronal plane parallel to the skin, which provides new diagnostic information and enhances lesion characterization.

“Thanks to its advanced features, every sectional plane of the examined volume can be visualized, overcoming operator-dependent limitations and non-standardized documentation.”

Study Findings on 3D Ultrasonography

A study by Meyberg-Solomayer et al. involving 65 patients with breast lesions highlighted the advantages of 3D ultrasonography:

• Enhanced Infiltrative Zone Visualization: 3D ultrasonography, when used as an adjunct to 2D ultrasonography, provides a more accurate depiction of the infiltrative zone.
• Coronal Plane Benefits: The coronal plane is particularly beneficial for visualizing indistinct infiltrative zones.
• Surface Mode: Useful for imaging complex structures like multinodular fibroadenoma.

The study found that the diagnostic accuracy of 3D ultrasound is almost comparable to 2D ultrasound, but using 3D ultrasound as an adjunct improves confidence in diagnosing breast lesions by offering better characterization of breast masses.

3D ultrasonography significantly enhances breast imaging by providing detailed sectional planes, standardized documentation, and new diagnostic perspectives through coronal plane imaging. These features make it a valuable adjunct to traditional 2D ultrasound and other breast imaging techniques, thereby improving the accuracy and confidence in diagnosing breast lesions.

 

Planes Obtained in Breast Ultrasonography

Comparing 2D and 3D Ultrasonography

3D ultrasound scanning produces images in the sagittal, transverse, and coronal planes, while 2D ultrasound is limited to the sagittal and transverse planes. The sagittal and transverse planar sections of the 3D scan are comparable to those obtained with conventional 2D ultrasound. However, 3D breast ultrasonography offers the significant added advantage of coronal plane imaging.

Advantages of Coronal Plane Imaging

The inclusion of the coronal plane in 3D ultrasound provides a more comprehensive view of breast anatomy and pathology. This additional plane allows for:

• Better Visualization: Enhanced visualization of the extent and characteristics of breast lesions.
• Detailed Assessment: A more detailed and accurate assessment of breast abnormalities.

“The ability to view images from multiple planes simultaneously enhances the diagnostic process, enabling a thorough analysis of the breast tissue from different angles.”

Multi-Planar Capability

The sectional images in the transverse, sagittal, and coronal planes obtained through 3D breast ultrasonography can be rotated in any direction and visualized simultaneously on the screen. This multi-planar capability provides several benefits:

• Comprehensive Analysis: Allows radiologists to assess breast anatomy from various angles.
• Enhanced Diagnosis: Improves identification of the size, shape, and extent of lesions.

Improved Diagnostic Accuracy

The ability to rotate and view these planes concurrently enhances the diagnostic process by providing a more detailed and accurate depiction of the breast tissue and any abnormalities present. This advanced visualization aids in:

• Better identifying the size, shape, and extent of lesions.
• Improving the accuracy of the diagnosis.
• Enhancing the effectiveness of treatment planning.

 

Criteria Used to Analyze Lesions in Breast Ultrasound

Parameter		Definition
Shape
Irregular (#)		Not oval or round
Oval (*)		Oval in shape, maximum. three smooth lobulations
Round (*)		Round, Spherical
Orientation
Vertical (#)		Axis is vertical to skin, more tall than wide.
Indifferent (#)		In spherical lesions, when the posterior margin is not discernable because of strong shadowing
Parallel (*)		Axis is parallel to skin; more wide than tall, horizontal
Echogenicity
hypoechogenic (#)		remarkably lower echogenicity compared to fatty tissue
Isoechogenic (*)		Equal or slightly lower echogenicity compared to fatty tissue
Hyperechogenic (*)		Higher echogenicity compared to fatty tissue, for e.g. fibroglandular tissue
Echo pattern
Complex (#)		Zones with noticeably different echogenicity within the mass
Homogeneous (*)		Almost similar echogenicity throughout the mass
Hyperechogenic spots
Present (#)		Punctuated widely with hyperechogenic foci inside a hypoechogenic halo
Absent (*)		Not punctuated widely with hyperechogenic foci
Margin contour
Irregular/spiculated (#)		Uneven margins(e.g. angular margins, spiculate, microlobulation, , branch patterns)
Smooth/lobulated (*)		Even margin without irregularities or not more than five undulations
Margin
Indistinct (#)		Blurry , Not circumscribed, exact location of the margin is difficult to demarcate
Circumscribed (*)		Clear demarcation between surrounding tissue and tumor
Lesion boundary
Hyperechogenic halo (#)		Irregular,blurred, hyperechogenic rim surrounding the lesion
None (*)		No echogenic halo or thin capsule
Thin capsule (*)		clear thin hyperechogenic rim at the margin of the lesion
Posterior acoustic features
Shadowing (#)		posterior echoes reduced , also combined features ( enhancement and shadowing or indifferent posterior echoes and shadowing )
Enhancement (*)		enhanced posterior echoes
Indifferent (*)		No enhancement or shadowing
Surrounding tissue
Architectural distortion (#)		Disturbance of the anatomical structures, stoppage of glandular tissue and cooper ligaments.
Compression (*)		anatomical structures are maintained , cooper ligaments are displaced
Indistinct (*)		Difficult to separate if there is a structural compression or a distortion
Definitions of 3D ultrasound features studied in the “coronal” plane of the 3D ultrasound
Retraction
Present (#)	Fibrous Hyperechogenic ligaments of the breast running concentrically to the growth
Absent (*)	Encompassing tissue not disturbed in its orientation or compressed and relocated
Indistinct (*)	uncertain whether the encompassing tissue is retracted or not altered by the lesion
Margin contour	Definition identical to the criteria utilized as a part of conventional ultrasound imaging
Margin	Definition identical to the criteria utilized as a part of conventional ultrasound imaging

Basic methodology of the ultrasound analysis of breast lesions

Characteristics of Tumors on Breast Ultrasound

Malignant Tumors

On breast ultrasound, malignant tumors typically present with the following features:

• Irregular Margins: The edges of the tumor are uneven and not well-defined.
• Weak Internal Echoes: The echoes within the tumor are weak and unevenly distributed.
• Significant Acoustic Attenuation: There is a notable reduction in the strength of the ultrasound signal as it passes through the tumor.
• Changes in Breast Architecture: Malignant tumors often cause thickening or retraction of Cooper’s ligaments, altering the breast’s overall structure.

“Malignant tumors exhibit weak internal echoes with a non-uniform distribution and are associated with significant acoustic attenuation.”

Benign Tumors

In contrast, benign tumors on breast ultrasound have distinct characteristics:

• Smooth Margins: The edges of the tumor are even and well-defined.
• Uniform Internal Echoes: The echoes within the tumor are weak but evenly distributed.
• Minimal Acoustic Attenuation: There is little to moderate reduction in the strength of the ultrasound signal.
• Unaltered Breast Architecture: Benign tumors do not affect Cooper’s ligaments, maintaining the normal structure of the breast.

“Benign tumors appear as solid masses with smooth margins and well-defined edges.”

Diagnostic Insights

Breast ultrasound provides crucial information about the likelihood of a tumor being benign or malignant based on the characteristics of the breast masses:

• Malignant Indicators: Irregular margins and significant acoustic attenuation are more indicative of malignancy.
• Benign Indicators: Smooth margins and uniform internal echoes suggest a benign nature.

If further confirmation is required, a biopsy can be performed to obtain a definitive diagnosis.

Primary Use of Ultrasound in Breast Imaging

The primary use of ultrasound in breast imaging is to differentiate between cystic and solid masses. Breast tumors are classified as cystic, benign, or malignant based on their shape, margins, internal echo features, and the way sound waves return to the transducer after passing through the tumors. Here are the general features used for differentiation:

Cystic Masses

• Anechoic: Cysts typically do not show internal echoes even when the gain is high.
• Debris: Presence of debris within the cysts can produce reflections that complicate the diagnosis.
• Sound Transmission: Cysts increase the transmission of sound through the tumor. However, fibrosis around the cysts can cause sound attenuation, necessitating aspiration for accurate diagnosis.
• Aspiration: Often needed to confirm the diagnosis, especially if debris is present.

“Cysts are anechoic and increase the transmission of sound through the tumor, but fibrosis can cause sound attenuation.”

Solid Masses

• Acoustic Enhancement: Solid masses with uniform composition may cause acoustic enhancement posteriorly if the sound passes through them with less attenuation than the surrounding tissues.
• Edge Shadows: Both solid masses and cysts can produce edge shadows due to refraction if the lesions are oval or round.

Benign Tumors

• Shape: Generally ovoid in shape.
• Internal Echoes: Uniform internal echoes.
• Sound Transmission: Increased sound transmission.

“Some malignant tumors can also exhibit benign features, making it important to consider the overall context.”

Malignant Tumors

• Sound Attenuation: Typically produce significant attenuation of sound as it passes through them.
• Shadowing: Complete or heterogeneous shadowing is a characteristic of concern and requires further evaluation.
• Benign Overlap: Some benign lesions, such as fibrotic fibroadenomas, can also cause sound attenuation.

The features of benign and malignant tumors can overlap, with some benign tumors displaying malignant features and vice versa. Therefore, while ultrasound provides critical initial information about the nature of the breast masses, additional diagnostic procedures, such as biopsy, are often necessary for a definitive diagnosis.

Limitations of 3D Breast Ultrasound

Breast ultrasound is an excellent tool for guiding breast biopsies and other procedures due to its ease of use and continuous real-time imaging capabilities. While 3D breast ultrasound offers greater accuracy in detecting breast cancer compared to conventional ultrasound, it does have certain limitations:

• Larger Equipment: The machine setup for 3D breast ultrasonography is larger and more cumbersome than conventional ultrasound equipment.
• Data Input: 3D ultrasound requires more data input from the operator, which can complicate the procedure.
• Processing Time: Unlike conventional ultrasound, where images appear almost instantaneously, 3D ultrasound relies on different algorithms that can vary in processing time. Some algorithms provide immediate results, while others take longer.
• Operator Experience: It can be challenging for inexperienced operators to determine the appropriate algorithm or perspective from which to analyze the images.

“3D ultrasound requires more data input from the operator, which can complicate the procedure and vary in processing time depending on the algorithm used.”

Despite these limitations, the enhanced accuracy of 3D breast ultrasound makes it a valuable tool in the detection and diagnosis of breast cancer. Continuous education and training can help operators overcome these challenges and fully utilize the benefits of 3D ultrasound technology.

Future of Breast Ultrasonography

Continuous research is being conducted to enhance the capabilities of breast ultrasound. Here are some key areas of focus:

• Doppler Ultrasound: Efforts are underway to simultaneously capture details such as tumor blood flow and vascularity using Doppler ultrasound.
• Contrast Agents: The development of various contrast agents for breast imaging is aimed at improving detail and accuracy.
• Software and Hardware Improvements: Better software and hardware are being developed to create ultrasound equipment capable of extracting more physiological and mechanical data than conventional machines.

“These advancements aim to improve the differentiation between benign and malignant breast lesions, thereby enhancing breast cancer detection.”

Current Research Focus

Improving the predictive power of breast ultrasound to distinguish benign tumors from malignant ones remains a key focus of ongoing research. Additionally, there are challenges in registering and co-registering breast ultrasound images with other imaging modalities, such as digital breast tomosynthesis (DBT). Addressing these issues is another significant area of current research.

• Predictive Power: Enhancing the ability to accurately differentiate between benign and malignant tumors.
• Image Co-Registration: Improving the integration of breast ultrasound images with other modalities like DBT.

“Overall, the continuous advancements in breast ultrasound technology aim to provide more accurate and comprehensive analysis of breast lesions, ultimately improving patient outcomes in breast cancer diagnosis and treatment.”

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FAQs on 3D Breast Ultrasound

1. What are the advantages of using 3D breast ultrasound over conventional ultrasound for breast imaging?

3D breast ultrasound provides more accurate detection of breast cancer compared to conventional ultrasound. It offers continuous real-time imaging, which is beneficial for guiding biopsies and other procedures. Additionally, 3D imaging allows for better visualization of breast structures from multiple angles, improving the detection and characterization of lesions.

2. What are some limitations of 3D breast ultrasound compared to conventional ultrasound?

The limitations of 3D breast ultrasound include larger machine setup requirements, the need for more data input from the operator, and varying image appearance times depending on the algorithm used. Some algorithms provide instantaneous images, while others may take longer. Additionally, it can be challenging for inexperienced operators to decide on the appropriate algorithm or perspective for image analysis.

3. How is research improving the capabilities of breast ultrasound?

Research is focused on enhancing breast ultrasound by capturing additional details such as tumor blood flow and vascularity using Doppler ultrasound. Efforts are also being made to develop better software and hardware, as well as various contrast agents, to improve the detail and accuracy of breast imaging. These advancements aim to improve the differentiation between benign and malignant lesions, thereby enhancing breast cancer detection.

4. What is one of the primary goals of continuous breast ultrasound research?

One of the primary goals of continuous breast ultrasound research is to improve the predictive power of the technology in differentiating between benign and malignant breast tumors. This involves developing more advanced techniques and tools that provide clearer, more accurate images and data to aid in the diagnosis and treatment of breast cancer.

5. What challenges are associated with the registration of breast ultrasound images with other imaging modalities?

One of the significant challenges in breast ultrasound research is the registration and co-registration of ultrasound images with other imaging modalities, such as digital breast tomosynthesis (DBT). Ensuring accurate alignment and integration of images from different modalities is crucial for comprehensive breast cancer diagnosis and treatment planning, and overcoming these challenges is a key area of current research.