Interventional MR imaging

Most of the applications of MRI-guided interventional examinations require real-time or quasi real-time imaging. With sequences such as TFE (Turbo-Field-Echo), TSE (Turbo-Spin-Echo), EPI (Echo-Planar-Imaging), and GRASE (Gradient-and Spin-Echo), as well as with intelligent approaches such as LoLo (Local Look), data acquisition is alrady close to meeting these requirements. The specific advantages and drawbacks of these sequences are characterised in brief. Potential applications of MRI-guided techniques in interventional radiology, of which some have been tested to date in a small numer of patients, are: percutaneous biopsy, stereotactic emplacement of electrodes for deep encephalography, percutaneous interstitial therapy, percutaneous drainage, percutaneous application of focused ultrasound, and vascular interventions. (orig./MG)