Lesion 3D modeling in transcranial MR-guided focused ultrasound thalamotomy.Transcranial magnetic resonance-guided focused ultrasound (tMRgFUS) allows to perform incisionless thermoablation of deep brain structures.  Currently, feedback of the thermoablation process is based on peak temperature readings assessed on real-time two-dimensional MRI thermometry.  However, an accurate methodology relating thermal dosimetry with three-dimensional topography and temporal evolution of the lesion is still to be defined, thus hurdling the establishment of well-defined, evidence-based criteria to perform safe and effective treatments.  In here we propose threshold-based thermoablation models to predict the volumetric topography of the lesion (whole lesion and necrotic core) in the short-to-mid-term based on thermal dosimetry estimated from intra-treatment MRI thermometry.  We used intra-treatment MRI thermometry to estimate whole-treatment three-dimensional thermal dose maps, defined either as peak temperature reached (Tmax) or thermal isoeffective dose (TID).  The core at post-24h and whole lesion at post-3M lesions reported a similar behavior in terms of shape accuracy (SDc ~0.35), and thermal dose thresholds ~55 °C/4100.0 CEM43.  These thermoablation models could contribute to the real-time decision-making process and improve the outcome of tMRgFUS interventions both in terms of safety and efficacy.
THERM