LAUSR

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive procedure that produces real-time thermal damage estimate (TDE) of the ablative area. Measurements of TDE by hand across a full ablation can be time-consuming, and currently, no reliable image analysis exists for measuring TDE dimensions efficiently. Ablations were performed with the Visualase MRI-Guided Laser Ablation System (Medtronic). Selection criteria included single-laser catheter use and available ablation data in 2 planes. Central TDE lengths and widths postsingle ablation dose were calculated using our developed MATLAB algorithm and compared to manual measurements by 2 raters. The Bland-Altman model and Student's t-tests were used to characterize value differences between the 2 methods. A total of 42 TDE images across 21 patients were included. The mean differences in TDE length for rater 1 vs algorithm, rater 2 vs algorithm, and rater 1 vs rater 2 were −0.12 mm (SEM = 0.18), −0.54 mm (SEM = 0.17), and 0.42 mm (SEM = 0.17), respectively. The mean difference in TDE width for rater 1 vs algorithm, rater 2 vs algorithm, and rater 1 vs rater 2 were 0.45 mm (SEM = 0.16), −0.46 mm (SEM = 0.16), and 0.91 mm (SEM = 0.12), respectively. For both lengths and widths, student's t-tests show no significance differences across rater 1 and rater 2 vs algorithm (P > .1) and between raters (P > .05). Our iterative algorithm provides a reliable method for calculating TDE dimensions. Compared to manual measurements, the differences in TDE length and width are negligible. This computational tool allows for measurement of TDE for large sets of MRgLITT data within minutes.