Inovations in breast imaging

1. Inovations in Breast Imaging: Beyond
Mammography
When most people think of breast imaging, they think only of
mammography. While mammography remains the mainstay of breast
imaging, this subspecialtyarea of radiology has evolved rapidly and
substantially during the last several decades to include several
other advanced technologies that aid in the detectionand diagnoses of
breast diseases. Ultrasound and MRI have also becomestandard
components of breast imaging practices, along with breast interventional
radiology.
With this evolving technology, comes the evolving role of the breast
imaging radiologist. In the past, breast imaging radiologists solely
interpreted imaging and provided reports to referring physicians. Today,
breast imaging radiologists play an integral part of a multidisciplinary
team caring for patients with breast cancer and other breast health
issues.
Breast thomosyntesis
Breast tomosynthesis,also called three-dimensional (3-
D) mammography and digital breast tomosynthesis (DBT), is an
advanced form of breast imaging, or mammography, that uses a low-
dose x-ray system and computerreconstructions to create three-
dimensional images of the breasts. Breast tomosynthesis aids in the
early detectionand diagnosis of breast disease.
An x-ray (radiograph) is a noninvasive medicaltest that helps physicians
diagnose and treat medicalconditions. Imaging with x-rays involves
exposing a part of the bodyto a small dose of ionizing radiation to
produce pictures of the inside of the body. X-rays are the oldestand
most frequently used form of medicalimaging.
While mammography is the best screening tool for breast cancer
available today, it does not detectall breast cancers. Breast
tomosynthesis overcomessome of the limitations of standard
mammography, but it is not yet available in all imaging facilities.
A conventional x-ray examination of the breast, called a mammogram,is
two-dimensional: two x-ray images are taken of the breast, from top-to-
bottom and from angled side-to-side,while the breast is compressed

2. between a clear plastic paddle and an imaging detector.Although
compressionis necessaryto obtain breast images, it may cause
overlapping of the breast tissue in which abnormal tissue can be hidden
and superimposed normal tissue can appear abnormal.
Breast tomosynthesis can be used to perform screening mammography,
a test to detectearly breast cancer in women experiencing no symptoms.
Screening mammography with breast tomosynthesis has been shown to
improve accuracy and reduce false positive rates in women of all breast
densities.The largest improvements with tomosynthesis are seen in
women with dense breast tissue, but women with non-dense breasts
also demonstrate significantly better cancer detectionand significantly
fewer false positive findings when tomosynthesis is used.
In breast tomosynthesis,the x-ray tube moves in an arc over the
compressed breastcapturing multiple images of each breast from
differentangles. These digital images are then reconstructed or
"synthesized" into a set of three-dimensionalimages by a computer.
These three dimensional image sets help minimize the tissue overlap
that can hide cancers or make it difficultto distinguish normal
overlapping breast tissue from tumors.
BreastUltrasound
However, mammography is not the only tool breast imaging radiologists
use to detectand diagnose breast diseases. Breastultrasound is often
performedcontemporaneouslywith mammography in the diagnostic
setting to evaluate breast lesions.Adding ultrasound to mammography
for better characterization of breast masses improves diagnostic
specificityand reduces the number of benign biopsies.
The modality has also been used for whole-breast screening and has the
demonstrated ability to detectsmall cancers that are clinically and
mammographically occult in women with dense breasts.However,
several challenges limit the adoption of ultrasound as a common
screening method, including operatordependence,physician time to
perform the study, and a high rate of false-positive biopsies.
MRI
In addition to ultrasound, MRI is used by breast imaging radiologists to
detectabnormalities in breast tissue. BreastMRI is consideredthe most
sensitive imaging technique for detecting breast cancer. As a result, the

3. technique is being used increasingly on patients who are at high risk for
the disease.Breast MRI is also frequently used to monitor treatment
response to neoadjuvent chemotherapy,as studies have shown that
breast MRI has clinical utility for predicting recurrence-free survival and
pathologic complete response.
While breast MRI is a highly sensitive technique, it is supplemental
screening and should not be used alone. Rather, it should be used in
addition to mammography, as some cancers are undetectable by MRI,
yet visible with mammography. Breast MRI is not recommendedfor
screening women who have an average risk for breast cancer, due to a
high rate of false-positive biopsies.Advances in MRI technology and the
addition of newer techniques, such as diffusionweighted imaging, may
help improve the specificityof breast MRI.
BreastInterventions
In the past, management of a mammographically detected,but clinically
occult suspicious lesionwas problematic because it was difficult to
excise a nonpalpable lesion. Often the surgeon would resecta large
portion of the breast quadrant to ensure removal of the lesion. But the
developmentof mammographically guided needle-localization
techniques has allowed more precise excisions,with more conservation
of normal breast tissue. This localization can be performed under
mammography, ultrasound, or MRI guidance.
The developmentof image-guided percutaneous breast biopsyhas
expanded the role of the radiologistin managing breast imaging patients
further. Rather than localize a suspicious mammographic finding for a
breast surgeon to excise,the radiologistcan now obtain a sample
directly and provide a tissue diagnosis.Expediting the diagnosis in this
way decreases morbidityand improves cosmesis forthe patient, plus
decreasesheath care costs for society.
Given its benefits,image-guided percutaneous breastbiopsy is currently
considered the “first-line” approach for tissue diagnosis,while breast
surgical excisionis reserved for cases not amenable to an image-guided
biopsyor for cases where additional tissue is warranted to ensure
adequate sampling after initial image-guided biopsy.
A Critical Practice
Breast imaging has come a long way from the days of direct-exposure
films and rampant quality concerns.Breast imaging radiologists now

4. have more tools at their disposaland are more integrated into patient
care than ever before.As additional technologicalinnovations are
achieved and breast imaging radiologists continue to advance in their
expertise,mammography and other imaging techniques,like MRI,
ultrasound, and breast intervention, are expected to remain central to
early detectionefforts.
Early detectionremains a key to reducing mortality. Breast screening is
the most effective and affordable toolfor detecting breast cancer and we
continue to advocate for annual mammography screening starting at age
40.