الفهرس 
ANATOMICAL BACKGROUNDOnly 14 pages are availabe for public view
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Abstract
Carcinoma of the breast is the most common cancer in women
Early and accurate detection of breast cancer is critical to the
treatment and, ultimately survival of patients .
Complex clinical decisions about treatment of patients of breast cancer are largely guided by imaging findings, among other factors. Most radiologic procedures map the anatomy and morphology of tumors with little or no information about their metabolism.
The progress made in molecular imaging will lead to more specific therapy, accurate staging, and treatment monitoring resulting in improved survival and quality of life for patients with breast cancer.
The advantage of radionuclide techniques over other imaging approaches is the ability to label any chemical species with an isotope of choice.
Imaging devices that are specifically designed for breast imaging with enhanced spatial resolution will enable image-guided biopsies, and facilitate early detection and better therapy of breast cancer.
In recent years, imaging with positron emission tomography (PET) for tumor staging and therapy control has been introduced. Rather than anatomic information, it provides physiologic information on glucose uptake and metabolism.
The main drawback of PET in tumor imaging is the virtually complete absence of anatomic landmarks, which impedes precise localization of lesions . Furthermore, there are some issues regarding specificity because FDG is not only taken up by many malignant tumors but also by sites of active inflammation.
PET/CT is a more accurate test than either of its individual components.
PET/CT has advantages over other imaging methods; it can differentiate benign from malignant lesions, staging and restaging tumors detect functional changes before there is any change in clinical or radiological size of a mass, better in identify cancer that has spread, making up treatment plane and monitoring tumor response, detect tumor recurrence early and distinguish viable metabolically active tissue from
scars.
FDG-PET –CT can be helpful in the diagnosis of primary breast cancer, especially in patients with dense breast tissue, significant fibrocystic changes, fibrosis after radiotherapy, and inconclusive results from MR imaging and other imaging modalities. PET has a limited role in patients with very small tumors and with well-differentiated and lobular types of breast cancer.
The restricted sensitivity of FDG-PET does not allow the screening of asymptomatic women for breast cancer.
Advances in technology such as the development of dedicated breast imaging devices (eg, PEM) may improve the detection of primary tumors with PET in the future.
Positron-emission mammography may reduce unnecessary breast biopsies, demonstrated a 6% improvement in specificity compared with breast MR, and and is a better alternative for the 16% of women who cannot tolerate MR due to claustrophobia, metallic implants, body habitus, or gadolinium reaction
MRS is a quantitative method of display of non-aqueous proton signals that correspond to certain biological molecules in the tissues. The spectrum is a graph of the relative concentrations of these molecules based on their discrete radio frequency signal.
A high peak means that the molecule at that radiofrequency
location exists in greater concentration than an adjacent low peak. To be precise, it is the area under the peak that is relevant. Applying appropriate calibrations, the concentration of a given metabolite is calculated from the peak area.
Researchers in the field of breast cancer have developed a
magnetic resonance spectroscopy (MRS) method that quantifies breast tissue levels of choline (Cho) compounds, which the study found to be elevated in malignant lesions. Cho concentrations to be significantly higher in malignancies than in benign lumps and normal breast tissues using this quantitative method.
Scintimammography using various radiopharmaceuticals have been employed for their tumor affinity. 99mTc methoxyisobutylisonitrile (MIBI) has shown to be useful in the evaluation of malignant tumors. It has several advantages which are related to its small radiation dose to the patient and it has better physical characteristics for imaging by the gamma camera.
Scintimammography has limited ability to detect lesions less than 1 cm.
Scintimammography used as an adjunct to conventional imaging modalities in obviating benign biopsies and in detecting axillary nodal metastases and monitoring treatment.