الفهرس 
Anatomy of the Female BreastOnly 14 pages are availabe for public view
Abstract
east cancer remains the most prevalent cancer in women
of developed countries with great social and economic
impact. The scientific community is therefore focused on
improving imaging methods for screening and staging of breast
cancer. Conventional screening has traditionally included a
combination of breast self-examination, clinical breast
examination, and screening mammography.
Although current imaging modalities such as
mammography, ultrasonography, and magnetic resonance
imaging focus on an anatomic approach, they do not provide
sufficient data about the pathophysiology of malignant breast
lesions.
Positron emission mammography (PEM) is an innovative
technology specifically designed to visualize the physiologic
and metabolic processes in malignant breast lesions and can be
performed on patients unable to have an MRI scan.
The technology of PEM and PET are similar in that they
both provide functional imaging employing 18F-FDG. However,
PEM is optimized for small body parts and utilizes gentle
immobilization of the breast to attain higher spatial resolution (1–2
mm for PEM vs 4–6 mm for PET), as well as minimize the
radiation dose by reducing breast thickness.
B
Breast density, hormone replacement therapy, and
menopausal status did not interfere with lesion detection with
PEM. These factors are known to affect the glandular tissue of the
breast and make interpretation of classic imaging modalities
(mammography and MRI) challenging as far as cancer detection is
concerned.
Thus, with its ability to overcome certain limitations of MRI,
PEM was proposed as an appropriate alternative to MRI in the
presurgical management of breast cancer patients.
When PEM has been directly compared with PET and MRI,
the sensitivity was comparable to that of MRI and significantly
higher than that of PET, particularly in small tumors).
PEM has the potential to play a role in the initial staging of
breast cancer, particularly in patients at high risk for multifocal or
multicentric disease who desire breast conservation therapy and are
unable to undergo staging contrast- enhanced MRI mammography.
Evaluating early response to neoadjuvant chemotherapy
could be accomplished in earlier stage disease using PEM, because
of its superior spatial resolution relative to whole-body scanners.
Despite the obvious advantages of PEM technology, a few
limitations do apply for PEM scans. Firstly, the specificity of a
PEM scan can be attenuated because of high FDG uptake in cases
of innate hypermetabolism. Benign breast lesions, such as
fibroadenomas in the rapid growth phase, and acute or chron
inflammatory processes (e.g., fat necrosis) are known to result in
focal FDG uptake; however, these conditions can often be
differentiated from malignancy by conventional imaging.
Moreover, during a PEM scan, proper positioning of the breast is
essential because non-inclusion of the posteriorly located
malignancy in the field of view can result in false negative results.
Interpretation of PEM scans can also be challenging, especially in
lesions that are in close proximity to the chest wall, as well as in
larger breasts. Increased breast density has also been reported to
result in significantly higher FDG uptake.