Pre-surgery localization of non-palpable lesions of the breast using a 1.0 Tesla MRI system and a body coil

The purpose of the study was to verify whether examination with a non-dedicated MRI body coil, i.e. without complementing electronic hardware, will reliably locate the lesion revealed by the MR-mammography. The idea was that if the results obtained were equal in value, a less expensive alternative for tumor localization might have been found. Material and methods: In 18 patients we performed a contrast enhanced (i.v. 0.2 mmol Gd-DTPA/kg b.w.) breast MRI on a 1.0 Tesla system (Magnetom Impact, Siemens, Erlangen, Germany) using a body coil and a GRE 3D sequence. In prone position, the patients were placed in a customized positioning device offering lateral access to the breast. The localizations were done with a MRI-compatible wire (n=21). In addition, all patients underwent the same imaging protocol using a dedicated breast coil (without localization). For both MRI modalities, the signal intensities of the lesion, the normal breast tissue, and the background noise were measured. The lesion-to-fat contrast (LFC), the lesion-to-breast tissue contrast (LCB) and the percentage of signal change pre- and post-contrast administration were calculated and compared. The localization results were correlated to pathologic findings. Results: There was no difference in lesion detection. Regarding the LCF and LBC, the body coil was superior to the dedicated breast coil. However, the background noise was higher using the body coil. In all cases the localization was successful. (orig./CB)