High intensity focused ultrasound transducer optimization
When planning magnetic resonance (MR) guided high intensity focused ultrasonic (HIFU) therapy, HIFU transducer element parameters are optimized as a function of 3D MR data describing a size, shape, and position of a region of interest (ROI) ( 146 ) and any obstructions ( 144 ) between the HIFU transducer elements and the ROI ( 146 ). Transducer element phases and amplitudes are adjusted to maximize HIFU radiation delivery to the ROI ( 146 ) while minimizing delivery to the obstruction ( 144 ). Additionally or alternatively, transducer elements are selectively deactivated if the obstruction ( 144 ) is positioned between the ROI ( 146 ) and a given transducer element.
1. A method of performing an in-situ sonication simulation for an MR-guided high intensity focused ultrasound (HIFU) ablation procedure, including:
generating a patient-specific acoustic path model of a HIFU transducer that includes a plurality of HIFU transducer elements;
presenting the acoustic path model to a user via a user interface;
receiving user input regarding adjustments to at least one of (i) a position of one or more of the HIFU transducer elements and/or (ii) a transmission phase and amplitude of the one or more of the HIFU transducer elements; and
simulating a HIFU sonication of a region of interest (ROI) using the acoustic path model and the user input,
wherein simulating the HIFU sonication includes:
segmenting a volume of interest into subvolumes;
extracting and discretizing boundaries of the subvolumes;
positioning the HIFU transducer in a simulation domain;
specifying phases and amplitudes for the HIFU transducer elements in the HIFU transducer;
specifying one or more regions of interest (ROI) in the volume of interest;
selecting a first HIFU transducer element from the HIFU transducer elements;
launching a discrete computational phonon;
analyzing propagation characteristics of the launched phonon;
storing the launched phonon and path characteristic data in a phonon buffer that stores path characteristic data for a plurality of phonons;
retrieving a new phonon from the phonon buffer;
simulating phonon propagation for the new phonon;
determining whether a ray defining a path of the new phonon intersects one of the subvolume boundaries;
dividing the ray into a transmitted portion and a reflected portion if the ray intersects the one of the subvolume boundaries;
determining amplitude and phase information for each of the transmitted and reflected portions of the ray; and
storing the amplitude and phase information for each of the transmitted and reflected portions of the ray in the phonon buffer.
2. A method of performing an in-situ sonication simulation for an MR-guided high intensity focused ultrasound (HIFU) ablation procedure, including:
generating a patient-specific acoustic path model of a HIFU transducer that includes a plurality of HIFU transducer elements;
presenting the acoustic path model to a user via a user interface;
receiving user input regarding adjustments to at least one of (i) a position of one or more of the HIFU transducer elements and/or (ii) a transmission phase and amplitude of the one or more of the HIFU transducer elements; and
simulating a HIFU sonication of a region of interest (ROI) using the acoustic path model and the user input,
wherein simulating the HIFU sonication includes:
segmenting a volume of interest into subvolumes;
extracting and discretizing boundaries of the subvolumes;
positioning the HIFU transducer in a simulation domain;
specifying phases and amplitudes for the HIFU transducer elements in the HIFU transducer;
specifying one or more regions of interest (ROI) in the volume of interest;
selecting a first HIFU transducer element from the HIFU transducer elements;
launching a discrete computational phonon;
analyzing propagation characteristics of the launched phonon;
simulating phonon propagation for a new phonon;
determining whether a ray defining a path of the new phonon intersects one of the subvolume boundaries;
dividing the ray into a transmitted portion and a reflected portion if the ray intersects the one of the subvolume boundaries; and
determining amplitude and phase information for each of the transmitted and reflected portions of the ray.