Adaptive spatial compounding for improving ultrasound images of the epidural space

摘要: Epidural anesthesia can be a difficult procedure, especially for inexperienced physicians. The use of ultrasound imaging help by depicting the location epidural space to choose needle trajectory appropriately. Anatomical features in lower back are not always clearly visible because speckle poor reflection from structures at certain angles, and shadows from bony surfaces. Spatial compounding has potential reduce and emphasize structures by averaging number images taken at different isonation angles. However, beam-steered are not perfectly aligned due non-constant speed sound causing refraction errors. This means blur features. A non-rigid registration method, called warping, shifts each block pixels of the order find best alignment the reference image without beam-steering. By applying the features become sharper after compounding. To emphasize further, edge detection is also applied individual to select for warping parameters calculated real-time acquired image. In computational complexity, linear prediction vectors used. algorithm tested on phantom with probe. Qualitative comparisons made among original plus combinations compounding, warping, edge detection prediction. gradient and Laplacian Gaussian used quantitatively assess visibility the bone boundaries ligamentum flavum processed images. The results show significant improvement quality.