[Role of MRI in the diagnosis of breast diseases]. / Place de l'IRM dans le diagnostic des affections mammaires.

UNLABELLED: ADVANTAGES AND LIMITATIONS: Magnetic resonance imaging of the breast is probably the most sensitive method for detecting or ruling out breast disease. It is however not as specific as expected. TECHNIQUE: All examinations are performed with and without gadolinium intravenous administration, excepted in the case of silicone implant reconstruction mammoplasty. Dynamic contrast-enhanced MRI sequences are necessary with a permanent balance between temporal resolution, spatial resolution, and signal. MRI of the breast is not indicated as a routine examination in a screening program, neither to improve the specificity of infra-clinic lesions, nor in simply dense breasts without any known risk factor or in circumscribed masses. INDICATIONS: MRI is best used to improved the sensitivity of mammography and sonography in selected patients. The selected indications are: evaluation of the volume and extension of breast lesions evaluation of the therapeutic response after chemotherapy, and detection or exclusion of the local recurrence in patients with breast conservation therapy. PERSPECTIVES: The future indications and perspectives of MRI include interventional breast radiology (MRI-guided core biopsy), and thermocoagulation therapy. It may be interesting for the evaluation of patients with contrast enhanced MRI lesions with normal mammography and sonography, and also in woman with a genetically defined high breast cancer risk.

Anatomic study of the lumbar region applied to multiplanar imaging techniques: importance and use of oblique vertical sections.

This anatomic study of the lumbar region (as defined by Rouvière [11]) applied to multiplanar imaging techniques was carried out both in the cadaver and in vivo. The cadaver study (5 cases) consisted of anatomic sections (transverse, sagittal, frontal and oblique) and computerised three-dimensional reconstructions after CT studies on subjects injected with colored and radio-opaque latex. The in vivo study (4 cases) used MRI sections and three-dimensional ultrasound sections coupled with the pulsed doppler. The spatially referenced oblique vertical sections revealed the structures from unusual aspects, situating them amidst the retroperitoneal area with the maximum of topographic landmarks. The transposition of these results (obtained by sectional anatomy of the retroperitoneal region) to the new techniques of multiplanar formatting after MRI, ultrasound or CT data acquisition should optimise the investigation of certain retroperitoneal structures by specifying the ideal planes of section for each organ, while diminishing certain artefacts specific to acquisitions in the traditional planes of section. Oblique vertical sections seem eminently suitable for ultrasound location of the suprarenal compartments, study of the renal pedicles and topographic retroperitoneal location. This oblique vertical visualisation constitutes a fundamental resource for the development of video-monitored surgical procedures as it corresponds exactly to the axes of the access routes in percutaneous surgery of the kidney and the adjacent anatomic structures.