ABSTRACT
While the primary use of magnetic resonance imaging (MRI) in clinical practice remains in the diagnostic realm, the modality presents several opportunities for imaging guidance of percutaneous procedures not available with computed tomography (CT), ultrasound, or fluoroscopy. Procedures performed with CT and fluoroscopy expose both the patient and operator to
potentially harmful ionizing radiation. This is of particular concern in pediatric patients. The unparalleled soft tissue contrast of MRI also enables procedural targeting of structures not visible with other imaging modalities. Needle placement itself is facilitated by the ability to evaluate the needle in relationship to the imaging target in any arbitrary imaging plane. Finally, functional techniques, enabling visualization such as flow, perfusion, and diffusion may be utilized to identify appealing biopsy targets in the setting of oncologic imaging
John M. Morelli and Jan Fritz
CONTENTS
15.1 Introduction ............................................................................................................................................................... 333 15.2 Interventional MR Imaging: Technical Factors .................................................................................................... 334
15.2.1 Field Strength .............................................................................................................................................. 334 15.2.2 Safety ............................................................................................................................................................ 334 15.2.3 Needle Selection and Artifacts .................................................................................................................. 335 15.2.4 Image Acquisition for Guidance ............................................................................................................... 335 15.2.5 Injectant ........................................................................................................................................................ 336 15.2.6 Navigation Systems for MR-Guided Procedures ................................................................................... 336 15.2.7 Considerations at 3 Tesla ........................................................................................................................... 337 15.2.8 Cost Considerations ................................................................................................................................... 338
15.3 Back Pain Management ............................................................................................................................................ 338 15.3.1 Alternative Modalities ............................................................................................................................... 339 15.3.2 Technique ..................................................................................................................................................... 340
15.4 Temporomandibular Joint ....................................................................................................................................... 342 15.5 Joint Injections for Arthrography ........................................................................................................................... 342 15.6 MR-Guided Pelvic and Peripheral Nerve Injections ........................................................................................... 342
15.6.1 Obturator Nerve .......................................................................................................................................... 343 15.6.2 Pudendal Nerve Entrapment .................................................................................................................... 343 15.6.3 Posterior Femoral Cutaneous Nerve ........................................................................................................ 343 15.6.4 Sciatic Nerve Injections .............................................................................................................................. 344 15.6.5 Lateral Femoral Cutaneous Perineural Injections .................................................................................. 344
15.7 Musculoskeletal Biopsy and Aspiration ................................................................................................................ 345 15.8 Vertebroplasty ........................................................................................................................................................... 346 15.9 Bone Tumor Therapeutic Applications .................................................................................................................. 346 15.10 Summary .................................................................................................................................................................... 347 References ................................................................................................................................................................................ 348
and intervention. The following chapter will focus on current and future applications of interventional MRI with respect to the musculoskeletal system.
