MR-Guided Interventions – Indications, Technique, Pitfalls

Abstract

Different techniques have proved to be valuable for guidance of interventional procedures, namely, ultrasound, computed tomography (CT), and magnetic resonance (MR) imaging. For many indications all these techniques are “me too” alternatives. If there is no medical reason to prefer one imaging modality over another, factors such as availability, simplicity, and cost are of great importance. Looking at any of those cofactors, it is evident that MR imaging is the least likely method to be initially favored for guidance of interventional procedures. In this chapter only nonvascular interventions will be considered, such as imagingguided punctures/markings, drainages, and tumor ablations. Each radiologist performing any of these procedures should be familiar not only with the standard techniques of ultrasound and CT guidance, but also with guidance technique exploiting the imaging features of MR imaging. This is true despite the fact that there are so far only rare indications which definitely require MR imaging as a guidance tool. But some lesions which are only detectable by MR imaging require MR guidance or MR-guided localization and marking (Solomon et al. 2002). Among these, breast lesions are the most common and the continuously growing role of MR imaging in this field will lead to an increase in the numbers of breast lesions which can only be biopsied or marked by MR guidance.