Proper mammographic positioning is essential to the detection and diagnosis of breast cancer. Without properly positioned and exposed mammogram images, radiologists cannot clearly find the presence of abnormalities which would possibly require a biopsy. Skilled, dedicated mammographers must recognize the importance of their role and commit themselves to improving their skills so they can produce high-quality, well-positioned, and properly exposed mammograms on behalf of both the patient and the radiologist. This requires ongoing education and a thorough understanding of normal breast anatomy.
What is the purpose of mammography positioning?
The purpose of mammography positioning is to produce high-quality images for the radiologist to find abnormalities indicative of breast cancer at the earliest stage possible. A mammography technologist is responsible for positioning the breast in accordance with the American College of Radiology (ACR) Guidelines. According to Deborah Thames, lead technologist at MD Anderson Cancer Center in Houston, Texas & MTMI Instructor, an in-depth knowledge of breast anatomy and physiology can help improve technologists’ ability to perform quality mammograms. This early detection of breast abnormalities is potentially lifesaving.
Women at average risk of breast cancer should have a mammogram performed annually, starting at age 40. Women with higher-than-average risk should begin regular mammography screenings earlier and may benefit from additional diagnostic imaging modalities such as an MRI or Breast Ultrasound.
Why are there so many different mammography views?
The breast consists of soft tissue, and the variation in size and shape from patient to patient is more significant than other body parts. Standard views (as defined by ACR) are performed at every mammogram exam. Screening mammograms are performed on asymptomatic women that have no breast problems or new breast concerns.
When the two standard views fail to capture 100 percent of the breast tissue, supplemental views may be utilized. A patient’s body shape may inhibit the technologist’s ability to capture a complete image with the standard views, but other factors may also come into play. Patients with mental or physical disabilities may prevent standard views from being performed. Technologists can use supplemental and additional views to accomplish a complete breast imaging exam.
A diagnostic mammogram requires the use of additional views to provide the radiologist with more information needed for triangulation purposes – for patients with new breast concerns, high risk predisposition, or patients with a 5-year history of breast cancer. Mammographers may perform additional views that can reveal certain pathologies in the breast, some patients are called back for these views after a screening mammography exam. If two-dimensional imaging was initially performed, additional views can be performed for triangulation purposes. These additional views can help a radiologist determine whether an asymmetry is real and whether the patient could possibly need a breast biopsy.
How is mammography positioning different?
Most radiographic positioning involves bone structures, which are relatively standard anatomically from patient to patient. Technologists position patients to show frontal, lateral, and oblique angles of bones to create an image that can reveal fractures and/or diseases. Regardless of the patient, radiology technologists position most patients the same in every case, meaning there is a high degree of standardization.
On the other hand, mammography positioning involves soft tissue structures. Each patient’s breasts are different sizes and shapes. Mammography technologists need to become well acquainted with these variations and be able to skillfully position the breast to capture high-quality breast imaging exams for the radiologist. Not only does the mammographer have to be able to accommodate these differences adequately, but they must also account for the patient’s body habitus, which could prohibit good standard imaging. The ACR has recommendations for breast positioning to capture the whole breast in multiple views. Still, given the variations in breast size and shape and the potential limitations in patient mobility, mammographers must develop unique skills in positioning to acquire the images necessary to capture the whole breast in two standard views.
ACR Mammography Positioning Guidelines
The American College of Radiology (ACR) is an accreditation body that provides feedback on the quality of clinical images performed on each mammogram unit. The feedback gives information on 8 attributes of the images that are important for the quality of the mammogram. The staff is also checked for qualifications, mammography unit's phantom image for quality control, quality assurance, and regulated radiation dose to ensure they are in accordance with the Mammography Quality Standards Act (MQSA).
EQUIP
Most of the deficiencies in clinical imaging are the result of poor positioning. In an effort to improve mammograph positioning, the FDA implemented the Enhancing Quality Using the Inspection Program (EQUIP) in 2017. FDA-approved accreditation bodies, such as ACR, conduct a random validation image check (VIC) on 300 facilities each year to check on the quality of the mammographic images performed at those facilities to determine whether a facility is upholding required quality standards. These quality assurance checks verify imaging facilities are maintaining quality control records, regular equipment maintenance is performed, and corrective action is taken when necessary.
Standard Views
The ACR provides guidance on the best practice standards to help ensure the safe and effective use of mammographic imaging and lessen the variability among breast imaging practices. There are two standard views mammographers use in all types of mammograms: the craniocaudal (CC) view and the mediolateral oblique (MLO) view.
Craniocaudal (CC) View
The craniocaudal (CC) view is typically performed first in the mammography exam because the mammography unit is already at a zero-degree position, with the source of x-rays directed at the superior portion of the breast to the inferior portion of the breast that rests on the imaging receptor. It must be performed on both breasts.
CC view is ideal for showing central, anterior, medial, posterior tissue, but provides less information towards the lateral portion of the breast. The breast should be positioned with two hands to pull in the posterior tissue away from the chest wall and avoid folds underneath the breast. The contralateral breast should be brought up on the receptor to reveal the posterior-medial breast tissue, with the nipple centered on the detector. Ideally, the nipple should be in profile, but don’t sacrifice posterior tissue just to get the nipple in profile. The ACR states the nipple should be in profile in at least one view. On CC view, the posterior nipple line (PNL) measurement should start at the base of the nipple where it attaches to the skin, all the way back to the image with or without muscle. A potential issue mammographers tend to run into is that the nipple tends to fold under on large breasts, but this can be the natural position on pendulous breasts.
Mediolateral Oblique (MLO) View
For an MLO view, the breast is centered on the receptor, with the photocell markings about one to two centimeters above the nipple. The muscle should be wide superior with an anterior convex border down to the level of the PNL. The PNL measurement on MLO view should start at the base of the nipple where it attaches to the skin, measuring at a right angle of the muscle, about 45 degrees. The superior portion of the paddle reaches the second rib, while the posterior portion of the paddle should reach the imaginary line at the sternum. The inferior posterior tissue should be included in the image. Ideally, the inframammary fold (IMF) should be visualized without folds which can be accomplished by the mammographer running her fingers under IMF all the way down to the abdomen to alleviate folds closest to the detector.
Additional Views
- 90-degree lateral ML/LM - shows milk of calcium/triangulation for orthogonal views/change in lesion location relative to the nipple.
- Exaggerated CC XCCL/XCCM – shows extreme lateral or medial portions of the breast respectively.
- Cleavage view - shows an extreme medial portion of one or both breasts.
- Axillary view – shows areas of abnormalities in the axilla area.
- Tangential – shows calcifications in the skin by rolling the breast tissue, or it can bring palpable areas into the fatty portion of the breast.
- Rolled views - not needed as much because of Digital Breast Tomosynthesis (DBT) but reveals if an asymmetry is real or not by rolling the breast tissue to reduce superimposition.
- Implant displaced view - shows breast tissue without impedance from the breast implant. It is required to perform eight views for screening mammograms: Four views with implants in place and four views with implant displaced (ID) view or named push backs.
- Nipple in profile – getting at least two centimeters behind the nipple because that’s where most intraductal papillomas are located. The nipple must be in profile to reveal the retro areolar tissue without obstruction.
- AC anterior compression - shows anterior tissue portion of the breast well separated. This view shows the parenchymal breast tissue in a horizontal pattern.
- Spot compression views - Helps to show borders of lesions without superimposition of tissue while reducing breast thickness. See if a lesion is circumscribed or not.
- Magnification - usually done for calcifications to show more detail with size, shape, and form of calcifications to help determine if they need to be biopsied or not. Sometimes, these calcifications will get a BI-RADS 3.
The following views are not on The American Registry of Radiologic Technologists (ARRT) exam because they are rarely utilized and are not shown to new technologists becoming mammographers. Instead, they are considered part of the complete evaluation of true mammography performances.
- SIO-superior inferior oblique - an additional view used for posterior inferior tissue.
- LMO – opposite of MLO. It is done at about 135 degrees and is used for kyphosis and patients with pacemakers, defibrillators, or port-a-caths.
- From Below (FB) - used for kyphotic patients and patients with pacemakers, defibrillators, or port-a-caths.
Improve Your Mammography Positioning
According to Deborah Thames, 70-80% of accreditation failure is due to positioning errors. One of the best ways to obtain and maintain accreditation is through continuing education, where you’ll learn about mammography views and positions and how to achieve them consistently.
The Medical Technology Management Institute (MTMI) has several mammography training courses you can take to improve your imaging practice. If you are a technologist just starting in the field, our introductory mammography course will acquaint you with standard positioning practices. The EQUIP & Advanced Mammography Positioning Course takes a more comprehensive approach, ideal for experienced mammographers interested in enhancing their skillset to provide superior patient care. Facilities interested in improving their team’s positioning skills and imaging quality can participate in an MTMI individualized consulting program.
MTMI programs are taught by experts with national reputations in their fields and cover every modality. Our cross-training courses are offered in the classroom and via webinars and prepare you for registry exams, accreditation, and to take your career to the next level. Check out our full catalog of programs, or contact us with questions today!