3D visualization of vertebra by freehand ultrasound scanning

Paracentesis is a common operation for pain clinics and spinal anesthetics administration and requires empirical training and flexible skills to cope with the various cases of individual patients. We propose a method of measuring and visualizing three-dimensional vertebra shapes for assisting anesthesiologists, by an ultrasound imaging technique that is prevalent in many hospitals and has no harmful risks to the human body. The proposed system enables anesthesiologists to investigate vertebra shapes by freehand probing. Three-dimensional reconstruction and graphical rendering can be performed by monitoring the motion of the ultrasound probe and registering the scanned echography into the identical three-dimensional space. Considering the echography imaging features, volume rendering of hard tissue-surfaces is achieved and interactive measurement is possible. This paper describes the practicability of the proposed method based on experimental measurement of both phantom and real lumbar vertebrae and sacra.