How To Scan A Breast

  • Along with new techniques for ultrasound scanning, new institutions and organizations have arisen to help women obtain the highest quality breast ultrasound scans. The ARDMS Registry in Breast Ultrasound will emphasize modern scan techniques and identify individuals qualified to perform breast ultrasound. The AIUM breast ultrasound accreditation program helps ensure that breast imaging centers not affiliated with general imaging centers are performing high- quality breast ultrasound. Further work remains to be done on training centers for moving new technologies into clinical practice
























  • Set Up and Positioning
    • Adequate breast examinations can be performed with either high-frequency automated whole-breast ultrasound units or hand-held instruments with a transducer operating at 5 MHz or greater frequency, and with a depth of focus of no more than 3 cm.
    • Patients usually scanned in the supine position
    • Ipsilateral arm is raised above the head -- provides a more stable scanning surface
    • For the lateral margin of the breast -- patient can be rolled slightly toward the opposite side
    • For the medial portion of the breast -- supine position works well
    • If a lesion identified on mammo cannot be located with U/S, sitting the patient upright in the same position as the mammo may be helpful
  • Optimize the image quality with focusing, TGC, and overall gain.
    • Goal is to balance the image from the low-level echoes of the subcutaneous fat to the low level echoes of the retromammary fat
    • Moderate compression should be applied when scanning
  • In the case of a normal breast the usual protocol requires the following
    • Images of each quadrant
    • The subareolar ducts
    • Specific radial images of the breast -- depending on your sites protocol


ultrasoundbreastnormalsmall.jpg
Normal Optimized Tissue

















Scanning Technique
  • When a patient is being evaluated for a palpable breast mass or for a specific abnormality seen on mammogram, a preliminary scan is done first to locate the abnormality.
    • Helpful to mark the external skin over the mass
    • Transducer orientation should remain the same as with conventional U/S
    • Evaluate all lesions in two planes
    • Can be recorded with sagittal and transverse images or radial/anitradial transducer positions
    • Radial/Antiradial positions are unique to breast scanning
  • Radial scanning is critical for the detection of intraluminal mammary duct lesions.
  • Compression is important for characterization of solid masses
    • Cancers compress much less than benign lesions.
      • Solid masses may be isoechoic relative to the surrounding tissue especially when surrounded by fatty tissue, and looking for an area that does not compress as much as the adjacent tissue will help to detect the lesion.
    • Palpation during scanning allows for precisely localizing palpable abnormalities relative to the ultrasound image.
      • Palpation enables the examiner not only to find subtle lesions but also to determine when normal structures such as fat lobules and thickened Cooper's ligaments are causing a palpable abnormality.
  • Radial and Antiradial Scanning
    • All solid lesions should be scanned in the plane of the ductal system (radial and antiradial)
    • Demonstrates subtle projections that course toward the nipple or branch outward in the breast
  • If a nodule is scanned using only the conventional planes subtle findings may be missed
    • Lesions may falsely appear spheroid or ellipsoid
    • Lesions misclassified as probably benign
  • Optimization
    • Solid lesions may look cystic if gain is not properly set for breast scanning Image8.gif
    • Before scanning area of intrest, find an area of fatty tissue
      • usually inner aspect of breast
      • set gain so fat is medium grey
    • Compare all lesions in the breast with fat
      • If gain is set correctly glandular tissue and most benign lesions will appear isoechoic to mildly hypoechoic
      • Malignant lesions can be mildly hypoechoic to markedly hypoechoic
      • Cysts are markedly hypoechoic to anechoic
      • Structures hyperechoic to the fat include
      • Skin, fibrous tissue, and calcifications







Annotation

  • Labeling is extremely important in the identification and correlation of breast images from other modalities
  • Quasigrid pattern is popular
    • Views the breast as a clock face
    • Directly above the nipple on either breast is 12 o'clock
    • Right medial breast and left lateral breast are 3 o'clock
    • Directly below nipple on either breast is 6 o'clockar_breastultrasound_main_en.jpg
    • Right lateral and left medial breast are 9 o'clock
  • Many imaging centers will further subdivide the breast with three concentric circles
    • First ring - 1/3 of breast - encompassing area just outside nipple - Zone 1
    • Second ring - 2/3 of breast surface from nipple - Zone 2
    • Third ring - breast periphery - Zone 3
    • Lesions located close to the nipple are labled "A", lesions in the middle of the breast are labeled "B", and outer margin is labled "C"
  • Depth of any pathology is documented
    • Breast divided into thirds from skin to pectoralis major
    • Depth A is the most superficial third
    • Depth B is the middle layer
    • Depth C is the deepest third of the breast
    • Superficial lesions are labeled as "1", middle lesions as "2", and deep lesions "3"
  • Orientation of the mass is also important
    • Determined by aligning the transducer with the longest axis of a lesion
    • Identify whether its long axis is oriented in a radial or antiradial plane
    • Malignancies tend to grow within the ducts and will often follow the ductal system in a radial plane towards the convergence at the nipple

Lable Example -- RT BREAST 2:00 B3 RAD
  • Lesion is in the right breast, deeply situated towards the chest wall in the 2 o'clock position midway between the nipple and the outer margin of the breast, its long axis is oriented radially towards the nipple.


OTHER ANNOTATION EXAMPLES
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Ultrasound Pitfalls
  • Psuedomass
  • Infiltrative pattern
  • Large, fatty breast