Magnetic resonance imaging and spectroscopy of breast cancer

Abstract

Magnetic resonance imaging (MRI) has become one of the most important diagnostic tools in oncology. Dynamic contrast-enhanced (DCE) MRI of breast cancer provides information on functional features such as vascularity and vessel permeability in addition to morphology. This technique was found to give good differentiation of malignant and benign breast lesions. When analyzing the data, size and location of the user-defined region-of-interest influenced specificity of the examination. Possible indications for DCI-MRI are prooperative examinations prior to breast conserving surgery, postoperative evaluation, diagnosis of high-risk patients and monitoring of breast cancer treatment.

MR spectroscopy (MRS) can become a supplement to MRI for diagnosis and treatment monitoring of breast cancer. Basic meabolic information about breast tumor and non-involved tissue from the same breast has been obtained during several studies. This has been used to esablish the metabolic profiile of the tissue types and differences between them. Both extracts and intact tissue specimens have been examined from breast cancer patients. The findings document a variety of metbolic differences, especially in sugar content, certain amino acids and choline compounds. High content of choline compunds can also be detected in malignant tumors in vivo. Different data analysis can be chosen depending on the type of information wanted from the spectra. An external standard method was suggested for estimation of the in vivo choline levels in, while multivariate analysis of spectra was used to classify tumors and non-involved tissue samples based on their metabolic profiles. The most promising clinical potential for in vivo MRS is possibly monitoring of treatment response. In addition, the detailed metabolic information obtained from tissue somples can make ex vivo MRS a method for diagnosis of breast cancer, and possibly also for prognosis of metastatic disease.