title: MRI study of immediate cell viability in focused ultrasound lesions in the rabbit brain.
abstract: The purpose of this study was to evaluate cell viability in MR imaged focused ultrasound (FUS) lesions using cell-viability staining with triphenyl tetrazolium chloride (TTC) and both light and electron microscopy. Ten paired ultrasonic lesions were created in 5 rabbit brains in vivo with an ultrasound beam of 1.5 MHz electrical power input to the transducer of 50 W and exposure duration of 15 seconds. T2-weighted fast spin-echo (FSE) MRI was performed to detect the FUS lesions in the brain 4 hours after treatment, after which the animals were immediately euthanized. Lesion sizes were measured on TTC-stained specimens, histological sections stained with hematoxylin and eosin (H&E), and T2-weighted MR images. The differences between the lesion diameters measured with the three methods were within the range of 0.1--0.7 mm. The lesion sizes measured from MRI correlated well with those seen from H&E sections. The measurements from MRI slightly overestimated lesion sizes on TTC-stained wet tissues by approximately one MRI pixel (0.31 mm). Electron microscopy demonstrated nuclear and cytoplasmic ultrastructural damage within the grey-white, non-TTC-stained lesion zone, whereas the TTC-stained normal tissue showed preservation of neuronal ultrastructure. Therefore, MR-imaged lesions represent a cell-death zone in rabbit brain 4 hours after FUS ablation, with slight overestimation by approximately one MRI pixel. J. Magn. Reson. Imaging 2001;13:23-30.
authors.affiliation: Department of Radiology, Stanford University, Stanford, California 94305-5488, USA. Lili@s-word.stanford.edu
authors.forename: L
authors.initials: L
authors.lastname: Chen
authors.forename: D M
authors.initials: DM
authors.lastname: Bouley
authors.forename: B T
authors.initials: BT
authors.lastname: Harris
authors.forename: K
authors.initials: K
authors.lastname: Butts
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology*; D002470:Cell Survival; D008279:Magnetic Resonance Imaging; D008854:Microscopy, Electron; D011817:Rabbits; D013778:Tetrazolium Salts; D013997:Time Factors; D014465:Ultrasonics / Q000009:adverse effects*
chemical_list: D013778:Tetrazolium Salts