Diagnostic ultrasound ( PDFDrive )

CHAPTER 21 The Breast 769
A B RT 10 3B RAD LT 2 3B RAD
FIG. 21.12 Value of Split-Screen Mirror Ultrasound Image. (A) Mammography of both breasts showed a focal asymmetrical density in the
left breast, upper outer quadrant on the craniocaudal (CC) view (arrow). (B) Split-screen mirror-image ultrasound images show focal ibrous tissue
in the upper outer quadrant of the left breast that is markedly asymmetrical with the thickness of tissue in the mirror-image upper outer quadrant
location of the right breast. This collection of asymmetrical ibrous tissue is the cause of the mammographic asymmetry.
identiied, ive images of each breast should be acquired. 18 hese
include one image in one plane of each quadrant of the breast,
typically at the same distance from the nipple, and one image
of the retroareolar breast. he axilla can be scanned, but this is
not required.
When performing a targeted diagnostic ultrasound examination,
it is necessary to document that the area in question was
imaged. If the area is palpable, make sure to irst evaluate for
the palpable inding and place the probe immediately over this
location. If a inding is seen, then documentation as described
earlier is necessary. If no abnormal inding is seen—for example,
in the case of a mammographic asymmetry corresponding to
normal breast tissue—then documentation of that area showing
normal breast tissue is still necessary.
Split-Screen Imaging
Split-screen imaging capability is invaluable in breast imaging.
Split-screen images are most frequently used to compare mirrorimage
locations in the right and let breasts to document that
asymmetrical ibroglandular tissue causes either a mammographic
asymmetry or a palpable lump (Fig. 21.12). Split-screen
imaging can also be used to document dynamic events, such as
compressibility and mobility, on a single freeze-frame image and
in simultaneous mode, to show both the gray-scale image on
one side and the color or power Doppler image on the other. It
may also be used to document a inding in both orthogonal
views on the same screen.
Multiple lesions and lesions larger than the width of the
transducer require special techniques for demonstration. Of
several methods for demonstrating larger ields of view (FOVs),
one can use combined split-screen images or extended-FOV
imaging. Extended-FOV images can be helpful in demonstrating
very large lesions, multifocal and multicentric malignant lesions,
lymph node levels, implant integrity, or, as in Fig. 21.13, extensive
ibrocystic change (FCC) with numerous cysts of variable size
within the breast.
FIG. 21.13 Extended–ield-of-view (FOV) images shows extensive
ibrocystic change with numerous cysts of variable size within the
breast.
Special Breast Techniques
Doppler Sonography
One of the main purposes of Doppler ultrasound is to help classify
masses seen on ultrasound as benign or malignant. Once a breast
malignancy exceeds about 3 mm in size, it must stimulate
neovascularity to continue to grow. To accomplish this, tumors
elaborate a variety of angiogenesis factors. A net of peripheral
neovessels forms to nourish the rapidly proliferating periphery
of the tumor. Studies have been performed evaluating the presence
or absence of low, the distribution and pattern of vessels, vessel
density, peak systolic velocity (PSV), pulsatility index, and resistive
index (RI) and have found conlicting results, some demonstrating
that these measures could predict malignancy, but others showing
substantial overlap of indings. 19-23 As a result, Doppler cannot
be used independently to classify solid masses as benign or
malignant but rather should be used to supplement the routine
ultrasound evaluation.
hat being said, Doppler ultrasound can be used to diferentiate
solid masses from those that are cystic. Some markedly hypoechoic
solid nodules can have a pseudocystic appearance. Demonstrating