[Correction added on 16 August 2013 after first online publication: The author, ‘Zion Zilby’ was added in the list of authors for this article.]
Potential of magnetic resonance-guided focused ultrasound for intracranial hemorrhage: an in vitro feasibility study
Article first published online: 27 JUN 2013
© 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization
International Journal of Stroke
Special Issue: Global Stroke Statistics Edition
Volume 9, Issue 1, pages 40–47, January 2014
How to Cite
Harnof, S., Hananel, A., Zilby, Z., Kulbatski, I., Hadani, M. and Kassell, N. (2014), Potential of magnetic resonance-guided focused ultrasound for intracranial hemorrhage: an in vitro feasibility study. International Journal of Stroke, 9: 40–47. doi: 10.1111/ijs.12051
Conflict of interest: None declared.
- Issue published online: 19 DEC 2013
- Article first published online: 27 JUN 2013
- intracranial hemorrhage;
- magnetic resonance-guided focused ultrasound;
Intracranial hemorrhage has a mortality rate of up to 40–60% due to the lack of effective treatment. Magnetic resonance-guided focused ultrasound may offer a breakthrough noninvasive technology, by allowing accurate delivery of focused ultrasound, under the guidance of real-time magnetic resonance imaging.
The purpose of the current study was to optimize the acoustic parameters of magnetic resonance-guided focused ultrasound for effective clot liquefaction, in order to evaluate the feasibility of magnetic resonance-guided focused ultrasound for thrombolysis.
Body (1·1 MHz) and brain (220 kHz) magnetic resonance-guided focused ultrasound systems (InSightec Ltd, Tirat Carmel, Israel) were used to treat tube-like (4 cc), round (10 cc), and bulk (300 cc) porcine blood clots in vitro, using burst sonications of one-second to five-seconds, a duty cycle of 5–50%, and peak acoustic powers between 600 and 1200 W. Liquefied volumes were measured as hyperintense regions on T2-weighted magnetic resonance images for body unit sonications (duration of one-second, duty cycle of 10%, and power of 500–1200 W). Liquefaction efficiency was calculated for brain unit sonications (duration of one-second, duty cycle of 10%, power of 600 W, and burst length between 0·1 ms and 100 ms).
Liquified lesion volume increased as power was raised, without a thermal rise. For brain unit sonications, a power setting of 600 W and ultrashort sonications (burst length between 0·1 and 1·0 ms) resulted in liquefaction efficacy above 50%, while longer burst duration yielded lower efficacy.
These results demonstrate the feasibility of obtaining reproducible, rapid, efficient, and accurate blood clot lysis using the magnetic resonance-guided focused ultrasound system. Further in vivo studies are needed to validate the feasibility of magnetic resonance-guided focused ultrasound as a treatment modality for intracranial hemorrhage.