A Patient-specific Preplanning Treatment Algorithm for Focused Ultrasound Therapy of Spinal Cord Injury

Abstract: Focused ultrasound (FUS) is an increasingly prevalent therapeutic tool used in medicine to treat patients non-invasively, cost-effectively, and without any ionizing radiation. Depending on the clinical application, therapeutic ultrasound can be used for tissue ablation, physiotherapy, lithotripsy, and drug delivery, among other therapies. For the treatment to be effective, it is important to understand the acoustic pressure profile in the tissue to ensure the focal point intensity is sufficient to achieve therapy without damaging the tissue. In spinal cord injury (SCI), where FUS is hypothesized to promote blood flow to the site of injury to facilitate healing, it can be difficult to predict the expected pressure wavefields in real-time. This challenge is due to the complex structure of the spinal cord and variations in acoustic properties within the field of view, leading to distortion of the ultrasound wave front. To address this issue, we present an automated approach to visualize beam propagation and acoustic pressure distribution to aid with placement of the FUS probe. By simulating propagation of the ultrasound beams through patient-specific Digital Imaging and Communications in Medicine (DICOM) images, therapy can be optimized to minimize tissue damage while providing adequate focusing and focal intensity. In this study, porcine spinal cord images acquired after acute SCI are used to determine optimal FUS transducer placement.