4D CT acquisition methods and their anticipated effects on image quality in dynamic CT-scanning of the wrist.

Four dimensional computed tomography (4D CT) has shown to be of value in the diagnosis of motion related wrist joint pathologies. 4D CT can be performed with a variety of acquisition methods. However, the usability of 4D CT is affected by motion and image artifacts associated with the specific acquisition method used. In this literature review we inventorize which acquisition methods exist for 4D-CT imaging at different positions of the human body and what the advantages and disadvantages of each method are. Based on this assessment we formulate recommendations for the 4D CT imaging approach for diagnosing motion related wrist pathologies. We also address future perspectives of image acquisition in 4D CT of the wrist joint. We found that scanning in volumetric mode eliminates irregularity artifacts, while reducing acquisition time per frame reduces blurring artifacts. A reduced acquisition time can be achieved with short gantry rotation times, dual source CT and Reconstruction based on Partial Gantry Rotation (RPGR). However, the effect of RPGR on RPGR-specific artifacts and the effect of different acquisition times on apparent object displacements may be investigated in future research.