Mammography is a series of radiological imaging techniques using an x-ray machine that is essential in the detection and diagnosis of breast cancer.
Since breasts vary widely in shape and size, there is no one-size-fits-all imaging technique. Instead, skilled technicians must know which positions and techniques to employ for their various patients.
The positions used will also depend on the location of detected or suspected lesions. Their skills in positioning techniques enable quality detailed images that provide the most rapid and accurate diagnostics.
This guide will explore the main basic techniques used in mammography today.
How Is Mammography Positioning Different Than Other Body Parts?
Mammography is a non-invasive diagnostic tool that uses radiography techniques to visualize breast tissues and screen for things like cancer.
Most radiographic techniques involve imaging of bones that are very similar anatomically from patient to patient, allowing for a higher degree of standardization in the imaging process. They use frontal, lateral, and oblique angles to image the bones to diagnose diseases, abnormalities, and injuries.
Mammography, on the other hand, involves only soft tissues, and the techniques used can vary significantly from patient to patient because every patient’s breasts are unique in size and shape, and mobility issues can also create additional challenges. Therefore, there is no standardized technique since the positioning methods will vary with the tissues being examined.
As a result, mammography technologists must be well-versed in the variations to know which techniques to use and how to position the breast skillfully. These skills are critical for capturing high-quality images of the entire breast using the fewest number of views possible to limit the patient’s exposure to radiation.
Mammography Techniques
Since mammography is a type of X-ray, it uses electromagnetic radiation to create high-quality images of the soft tissues in the breast. Several different images are required to capture the entire breast, and the techniques used and how the breast is positioned will vary from patient to patient. The technician performing the imaging must also ensure that there is no motion artifact or blurring on any of the radiographic images so that they will be of sufficient diagnostic screening value.
Here are some of the most common techniques used in mammography today.
Mediolateral Oblique (MLO) View
The mediolateral oblique (MLO) is a standard technique used in every screening exam because it enables imaging of the largest amount of breast tissue. The image will have the nipple in profile and enable visualization of the inframammary fold.
It also includes the pectoralis muscle that extends down to the posterior nipple line, which is simply an oblique line drawn straight back from the nipple.
Craniocaudal (CC) View
The craniocaudal (CC) is another standard technique typically used in every screening exam because it also includes as much breast tissue as possible. If you measure straight back from the nipple, it should be within 1 cm of the posterior nipple line in the MLO view.
Lateral
The lateral view may be a mediolateral (ML) or lateral medial (LM) view, depending on the positioning of the imaging tube and detector. The ML view is used for lesions in the central or lateral breast and is positioned where the X-ray tube is medial, and the detector plate is lateral.
On the other hand, the LM view is best for examining medial lesions and has the X-ray tube lateral and the detector in the medial position.
Triangulation
Triangulation is the lining up of mammographic images from the greatest angle (lateral - 90 degrees) to the lowest angle (CC - 0 degrees). By convention, the order is from left to right: lateral, MLO, to CC.
Spot Compression
Spot compression, sometimes called a spot view, is a technique that spreads out the parenchyma tissue to decrease tissue overlapping. It is used to obtain high-quality images and to work up focal asymmetries. The technologist uses a smaller paddle to provide locally intense compression and more directed focal.
Magnification
Magnification views are critical for evaluating breast calcifications. Using a magnification stand in the CC and lateral techniques allows the work-up of microcalcifications. The breast is positioned on the magnification stand to decrease the focal area, which will magnify the tissues there. Since these techniques involve magnification, they require higher doses of radiation and longer exposure times.
Spot Magnification
Spot magnification techniques combine spot compression using a small paddle to compress the tissues with a magnification stand and settings. This technique is often employed when evaluating the margins of a mass or lesion. Technicians must be skilled at combining these techniques without pushing the lesion out of the field of view.
Rolled Medial & Rolled Lateral Views
Rolled medial and lateral views are used in the workup of an asymmetry on the CC view. In this technique, the technologist rolls the superior breast, either medial or lateral, while simultaneously rolling the inferior breast in the contralateral direction.
It is performed prior to compression and helps to separate the tissues. This technique allows superimposed tissues to spread out more while the lesions persist, producing quality images of the lesion.
Sometimes instead, CC views can be done at varying angles to achieve the same goal. The technique used may depend on the patient’s unique anatomy and the technologist performing the procedure.
Laterally Exaggerated CC (XCCL) View
A laterally exaggerated CC, an XCCL, view is used when more of the lateral breast tissue needs to be visualized to look for lesions and abnormalities.
Cleavage View
The cleavage view maximizes medial breast tissue visualization and assesses medial abnormalities.
Tangent View
The tangent view is performed when palpable abnormalities are present, which are lumps that can be felt by touch. To perform a tangent view, the technologist places a BB marker on the skin over the area in question and then produces an image with the BB in tangent view.
This imaging technique helps determine if the results from the mammography correspond to what the patient feels in their breast tissue.
Frequently Asked Questions
What Is the Best Position for a Mammogram?
The best mammography positioning depends on the patient's unique anatomy. However, the patient generally stands facing the machine with toes pointing forward and leaning in slightly. Different techniques are used for breast positioning, compression, and angle, which vary depending on the shape and size of the breast and the specific imaging techniques being used.
Final Thoughts
These basic techniques—the MLO, CC, lateral, spot compression, magnification, cleavage, tangent, and others—are all essential tools used to screen and diagnose breast tissue abnormalities like cancer. Since breasts vary widely in size and shape, skilled technicians must learn which positioning techniques to use for their specific patient and that patient’s concerns.
Using high-quality digital X-ray equipment will help ensure that your radiographic images are of sufficient quality to ensure rapid and accurate diagnostics, improving patient experiences and care.
