Rapid 3D human ribcage and kidney modeling for transcostal HIFU surgery

A rapid modeling technique for constructing human ribcage and kidney models for high intensity focused ultrasound through the ribcage is proposed and tested. In this study, a 3D model reconstructed from a patient's CT images provides solutions for the conversion of 3D image data into multi-part volumetric models of kidney and ribcage. The model was imported into PZFlex for simulation of acoustic field analysis. Tissue mimicking materials for the phantom were selected based on the acoustic characterisation result. The effect of the ribcage on HIFU sonication and acoustic pressure distribution were measured in the focal plane. Porcine ribcage sample was used in experiments for comparison. Results showed that with the presence of the ribcage phantom, the maximum temperature at the focus was reduced by approximately 60-70% and the maximum pressure at the focal zone was halved. Focus splitting with the ribcage in place was demonstrated both in experiments and simulations. The development of this model provides basis for using patient's data for transcostal HIFU research and maximise the efficiency of the HIFU surgery.