Spatiotemporal Monitoring of High-Intensity Focused Ultrasound Therapy with Passive Acoustic Mapping
- 1 January 2012
- journal article
- research article
- Published by Radiological Society of North America (RSNA) in Radiology
- Vol. 262 (1), 252-261
- https://doi.org/10.1148/radiol.11110670
Abstract
Purpose: To demonstrate feasibility of monitoring high-intensity focused ultrasound (HIFU) treatment with passive acoustic mapping of broadband and harmonic emissions reconstructed from fi ltered-channel radiofrequency data in ex vivo bovine tissue. Materials and Methods: Both passive acoustic emissions and B-mode images were recorded with a diagnostic ultrasound machine during 180 HIFU exposures of fi ve freshly excised, degassed bovine livers. Tissue was exposed to peak rarefactional pressures between 3.6 and 8.0 MPa for 2, 5, or 10 seconds. The B-mode images were analyzed for hyperechoic activity, and threshold levels were determined for the harmonic (1.17 mJ) and broadband (0.0137 mJ) components of the passively reconstructed source energy to predict tissue ablation. Both imaging methods were compared with tissue lesions after exposure to determine their spatial accuracy and their capability to help predict presence of ablated tissue. Performance of both methods as detectors was compared (matched-pair test design). Results: Passive mapping successfully aided prediction of the presence of tissue ablation more often than did conventional hyperechoic images (49 of 58 [84%] vs 31 of 58 [53%], P < .001). At 5.4-6.3-MPa exposures, sensitivity, specifi city, negative predictive value, and positive predictive value of the two methods, respectively, were 15 of 20 versus fi ve of 21 (P = .006), eight of nine versus eight of nine (P = .72), 15 of 16 versus fi ve of six (P = .53), and eight of 13 versus eight of 24 (P = .011). Across HIFU exposure amplitude ranges, passive acoustic mapping also aided correct prediction of the visually detected location of ablation following tissue sectioning in 42 of 45 exposures for which the harmonic and broadband threshold levels for tissue ablation were exceeded. Early cavitation activity indicated the focal position within the tissue before irreversible tissue damage occurred. Conclusion: Passive acoustic mapping signifi cantly outperformed the conventional hyperecho technique as an ultrasound-based HIFU monitoring method, as both a detector of lesion occurrence and a method of mapping the position of ablated tissue. (C) RSNA, 2011Keywords
This publication has 28 references indexed in Scilit:
- Passive cavitation mapping for localization and tracking of bubble dynamicsThe Journal of the Acoustical Society of America, 2010
- Passive cavitation imaging with ultrasound arraysThe Journal of the Acoustical Society of America, 2009
- Temporal and Spatial Detection of HIFU-Induced Inertial and Hot-Vapor Cavitation with a Diagnostic Ultrasound SystemJapanese Journal of Clinical Oncology, 2009
- Hyperecho as the Indicator of Tissue Necrosis During Microbubble-Assisted High Intensity Focused Ultrasound: Sensitivity, Specificity and Predictive ValueJapanese Journal of Clinical Oncology, 2008
- A passive array technique for cavitation mapping during HIFU treatmentThe Journal of the Acoustical Society of America, 2008
- Microwave thermal imaging of scanned focused ultrasound heating: Phantom resultsInternational Journal of Hyperthermia, 2008
- Applications of Acoustics and Cavitation to Noninvasive Therapy and Drug DeliveryAnnual Review of Fluid Mechanics, 2008
- Hyperecho in ultrasound images of HIFU therapy: Involvement of cavitationJapanese Journal of Clinical Oncology, 2005
- High-intensity focused ultrasound in the treatment of solid tumoursNature Reviews Cancer, 2005
- Increased heating by diagnostic ultrasound due to nonlinear propagationThe Journal of the Acoustical Society of America, 1990