title: Lesion generation through ribs using histotripsy therapy without aberration correction.
abstract: This study investigates the feasibility of using high-intensity pulsed therapeutic ultrasound, or histotripsy, to non-invasively generate lesions through the ribs. Histotripsy therapy mechanically ablates tissue through the generation of a cavitation bubble cloud, which occurs when the focal pressure exceeds a certain threshold. We hypothesize that histotripsy can generate precise lesions through the ribs without aberration correction if the main lobe retains its shape and exceeds the cavitation initiation threshold and the secondary lobes remain below the threshold. To test this hypothesis, a 750-kHz focused transducer was used to generate lesions in tissue-mimicking phantoms with and without the presence of rib aberrators. In all cases, 8000 pulses with 16 to 18 MPa peak rarefactional pressure at a repetition frequency of 100 Hz were applied without aberration correction. Despite the high secondary lobes introduced by the aberrators, high-speed imaging showed that bubble clouds were generated exclusively at the focus, resulting in well-confined lesions with comparable dimensions. Collateral damage from secondary lobes was negligible, caused by single bubbles that failed to form a cloud. These results support our hypothesis, suggesting that histotripsy has a high tolerance for aberrated fields and can generate confined focal lesions through rib obstacles without aberration correction.
authors.affiliation: University of Michigan, Department of Biomedical Engineering, Ann Arbor, MI, USA. yohankim@umich.edu
authors.forename: Yohan
authors.initials: Y
authors.lastname: Kim
authors.forename: Tzu-Yin
authors.initials: TY
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Xu
authors.forename: Charles A
authors.initials: CA
authors.lastname: Cain
mesh_terms: D004307:Dose-Response Relationship, Radiation; D006801:Humans; D059351:Organ Sparing Treatments / Q000379:methods*; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D012272:Ribs / Q000293:injuries* / Q000528:radiation effects*; D014464:Ultrasonic Therapy / Q000295:instrumentation / Q000379:methods*
references.citation: Abdom Imaging. 2011 Apr;36(2):185-95
references.pmid: 20512487
references.citation: Ultrasound Med Biol. 2010 Dec;36(12):2132-43
references.pmid: 21030142
references.citation: Ultrason Sonochem. 2004 May;11(3-4):149-54
references.pmid: 15081972
references.citation: Ultrasound Obstet Gynecol. 2011 Apr;37(4):450-7
references.pmid: 21433165
references.citation: J Acoust Soc Am. 1988 Jun;83(6):2190-201
references.pmid: 3411016
references.citation: J Endourol. 2007 Oct;21(10):1159-66
references.pmid: 17949317
references.citation: Ultrasound Med Biol. 1995;21(3):405-17
references.pmid: 7645132
references.citation: Med Phys. 2010 Jun;37(6):2533-40
references.pmid: 20632565
references.citation: J Urol. 2007 Aug;178(2):672-6
references.pmid: 17574617
references.citation: J Acoust Soc Am. 1990 Nov;88(5):2059-69
references.pmid: 2269722
references.citation: Ultrasonics. 2004 Apr;42(1-9):931-5
references.pmid: 15047409
references.citation: Ultrasound Med Biol. 2005 Dec;31(12):1673-82
references.pmid: 16344129
references.citation: J Acoust Soc Am. 2005 Jan;117(1):424-35
references.pmid: 15704435
references.citation: Acoust Phys. 2010 Sep;56(5):665-674
references.pmid: 21607120
references.citation: Phys Med Biol. 2008 Jun 7;53(11):2937-51
references.pmid: 18475006
references.citation: J Acoust Soc Am. 2006 Mar;119(3):1432-40
references.pmid: 16583887
references.citation: IEEE Trans Biomed Eng. 2010 Jan;57(1):93-102
references.pmid: 19651547
references.citation: Ultrasound Med Biol. 2010 Jun;36(6):888-906
references.pmid: 20510186
references.citation: IEEE Trans Ultrason Ferroelectr Freq Control. 2011 Feb;58(2):305-15
references.pmid: 21342816
references.citation: Med Phys. 2009 Aug;36(8):3495-503
references.pmid: 19746783
references.citation: Ultrasound Med Biol. 2006 Jan;32(1):115-29
references.pmid: 16364803
references.citation: Ultrasound Med Biol. 2006 Nov;32(11):1753-61
references.pmid: 17112961
references.citation: IEEE Trans Ultrason Ferroelectr Freq Control. 1998;45(4):989-1000
references.pmid: 18244253
references.citation: World J Gastroenterol. 2007 May 21;13(19):2747-51
references.pmid: 17569147
references.citation: Med Phys. 2010 Feb;37(2):848-60
references.pmid: 20229894