IMPLEMENTATION OF A 3D RENAL CALCULUS TRACKING SYSTEM FOR EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY

摘要

Shock wave lithotripsy is the common method for therntreatment of renal calculi. The shock waves canrndisintegrate a renal calculus if targeted accurately on therncalculus. If not targeted correctly, shock waves can causerninjuries to healthy tissue. Mainly because of breathing, therntarget moves continuously therefore the treatment is notrnoptimal when the targeting is static. Renal calculi trackingrnsystem, using ultrasound imaging, can improve thernefficiency of extracorporeal shock wave lithotripsy but itrnpresents limitations. Since the ultrasound imaging isrnshowing only a two dimensional slice through thernpatient’s body, the tracking is a two dimensional trackingrnmethod. Two dimensional tracking presents drawbacksrnwhen the ultrasound imaging plane is not ideally alignedrnwith the patient’s calculus trajectory. As a solution, arnthree dimensional renal calculi system is implemented andrnpresented here. The system uses a three dimensionalrnvolume as a reference to register the position of thernsubsequent two dimensional imaging. This system showsrnthat it can track the target of the shock wave with morernaccuracy and repeatability.