الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Neoadjuvant chemotherapy (NAC) is the favored treatment of choice among locally advanced breast cancer patients because it significantly increases the possibility of breast-conserving surgery. However, for non-responders, an early prediction of response to NAC is essential.
Magnetic resonance imaging is the first breast imaging modality that not only allows detailed visualization of the anatomy but also, when an intravenous contrast agent is administered or advanced sequences (e.g., diffusion-weighted imaging or spectroscopy) are used, provides functional information.
Magnetic resonance imaging (MRI) of the breast is an adjunct diagnostic procedure to mammography and ultrasound. Because of its high sensitivity and effectiveness in dense breast tissue, MRI can be a valuable addition to the diagnostic work-up of a patient with breast abnormality or biopsy-proven cancer.
Early change in tumor size measured on MR images is a good predictor of final response after Neoadjuvant chemotherapy (NAC). However, even if the cells respond to treatment, it takes some time for the tumor to shrink. Substantial research effort has been spent on investigating whether other information provided by MR imaging may serve as earlier response indicators than change in tumor size. Techniques that seem to be closest to clinical application, due to their feasibility and the promising results, are the pharmacokinetic analysis of DCE-MRI (Dynamic Contrast Enhanced- MRI), DW-MRI (Diffusion Weighted- MRI) and Spectroscopy.
Contrast enhanced MRI is valuable for diagnosis of small tumors in dense breast with the structural and kinetic parameters improved the specificity of diagnosing benign from malignant lesions. It is a complimentary modality for preoperative staging, to follow response to therapy, to detect recurrences and for screening high risk women.
DW MR imaging without contrast medium may provide diagnostic ability equivalent to that of contrast-enhanced MR imaging in detection of residual breast cancer after neoadjuvant chemotherapy.
The advantage of DW imaging to help visualize residual breast cancer without the need for contrast medium could be advantageous in women with impaired renal function.
Prediction of response to neoadjuvant chemotherapy with DW MR imaging might help physicians individualize treatments and avoid ineffective chemotherapy.
Combining in vivo MR spectroscopy (MRS) with contrast-enhanced MRI increases the specificity of breast MRI due to the additional biochemical information obtained with MRS.Subsequently, prognostic and diagnostic information is sought from the spectrum of malignant tumors. In prognosis, by yielding biochemical information on the tumor composition (eg: the presence of a hypoxic or a drug-resistant fraction), MRS could allow the selection of an appropriate treatment.