Tips and techniques in breast MRI.

The standard breast MRI protocol includes T2 sequences (anatomy and signal analysis), T1 gradient-echo sequences which can detect markers placed after biopsy, and injected dynamic 3D sequences for performing volume and multiplanar reconstructions, which are particularly useful for locating lesions well. Good patient positioning is essential and is obtained by using foam wedges for small breasts, ensuring there are no folds, and the correct position of the nipples. These aspects limit movement artefacts which alter subtraction sequences, so that it must always be possible for reading these sequences to be assisted by comparing them with the native sequences. New functional imaging sequences are now appearing in an attempt to increase the specificity of MRI, which is one of its main limitations. Of these, magnetic resonance spectroscopy appears to be the most promising, highlighting an abnormal choline peak in malignant lesions. This molecular signature provides early information (24 hours after beginning neoadjuvant treatment) on the chemosensitivity of a breast tumour.