LASER-INDUCED THERMAL LESIONS IN THE HUMAN BRAIN - SHORT-AND LONG-TERM APPEARANCE ON MRI

Purpose: The purpose of our study was to investigate with MRI the deve lopment of thermal lesions in the human brain up to almost 4 years aft er laser-induced interstitial thermotherapy (LITT). Method: Eighteen p atients with brain tumors who underwent LITT entered the study. Result s: In all patients the acute lesion comprised five concentric zones th at showed reverse signal intensities on T1- versus T2-weighted images. Lesion development over time was uniform in 89% of the lesions. In tw ocases variations were observed. Conclusion: The results of our MR fol low-up studies showed that post-LITT, laser-induced lesions will shrin k exponentially after an initial expansion without any pseudocystic ef fects.