Patient motion image artifacts can be minimized and re-exposure avoided by selective removal of a sequence of basis images from cone beam computed tomography data sets: a case series

This case series describes a reconstruction method applied to a cone beam computed tomography (CBCT) projection data set that used selected basis projection images to improve diagnostic image quality for patients who moved during the radiographic procedure. Reconstructed volumetric data from 6 patients at 2 institutions initially exhibited characteristic double contour images as a result of motion artifacts. For each case, the CBCT basis images from the entire projection data set were displayed as a cine sequence, and patient movement was identified during the first or last 90-degrees of a full 360-degree acquisition trajectory. Employing a useful reconstruction function of proprietary software, a secondary reconstruction was performed by discarding data acquired during the first and last 90-degree rotation. For all cases, this method provided a volumetric data set without motion artifact. General practitioners can apply this clinical method, whenever appropriate, to avoid a rescan and keep patient exposure "as low as diagnostically acceptable."