MR-Guided Thermotherapy of Abdominal Organs Using a Robust PCA-Based Motion Descriptor

Baudouin Denis de Senneville¹, ², Mario Ries², Chrit T.W. Moonen²

Thermotherapies can now be guided in real-time using magnetic resonance imaging. This technique is gaining importance in interventional therapies for abdominal organs. An accurate on-line estimation and characterization of organ displacement is mandatory to prevent misregistration and correct for motion related thermometry artifacts. Here we describe the use of a Principal Component Analysis to detect spatio-temporal coherences in the physiological organ motion and to characterize in real-time the complex organ deformation. During hyperthermia, incoherent motion patterns could be discarded, which enabled improvements in the compensation of motion related errors in thermal maps, as well as in the motion estimation robustness.