WE‐A‐L100E‐01: MR Data for Treatment Planning: Spatial Accuracy Issues, Protocol Optimization, and Applications (Preview of TG117 Report)

Image‐guided therapies, including stereotactic radiosurgery, biopsy procedures, IMRT and image‐guided surgery are being used with increasing frequency. Although originally based primarily on CT data, image‐guided therapies now frequently use MR data alone, or in conjunction with CT data in the planning of or real‐time guidance of interventional procedures. Unlike CT imaging, the spatial accuracy of MRI data depends on both an appropriate QC program and the choice of appropriate image acquisition techniques. TG‐117 seeks to provide guidance regarding the optimization of imaging protocols and necessary QC procedures when MR systems are to be used to obtain data for procedures in which high spatial accuracy is critical. This lecture will provide a preview of TG‐117, reviewing the physical bases for spatial distortions due to both system hardware and interaction of the system with the patient, describing methods for reducing or eliminating effects of distortion in MR imaging including protocol optimization and correction strategies, and presenting examples of QC tests for MR systems used to obtain data for procedures requiring high spatial accuracy. Educational Objectives: 1. Understand the physical bases for spatial distortions. 2. Understand image acquisition optimization and correction strategies for minimizing or eliminating effects of spatial distortions. 3. Understand issues related to QC testing for clinical applications requiring high spatial accuracy.