Influence of endourological devices on 3D reconstruction image quality using the Uro Dyna-CT.

Purpose: The urological Dyna-CT (Uro Dyna-CT) was established in clinical use for classical imaging as well as for interventional surgery. To evaluate whether irradiation artefacts may occur during interventional surgery, we analysed the impact of different instruments on 3D reconstruction in the Uro Dyna-CT.
Materials and Methods: Ten different endourological instruments [ureterorenoscope (URS)-fibrescope, percutaneous nephrolithotomy (PCNL) working sheath] and accessory equipments such as ureteral catheter, guide wires and stents (DJ, MJ) were introduced in a porcine renal pelvis either retrograde via the ureter or transparenchymally. Subsequently, digital fluoroscopy, standard X-ray and an Uro Dyna-CT were performed. Three colleagues evaluated the image quality independent from each other.
Results: There were basically no limitations regarding image quality in digital fluoroscopy and standard X-ray. In the Uro Dyna-CT, only with the URS fiberscope and the PCNL working sheath, small artefacts and irradiations were detected, whereas ureteric catheter with and without wire, as well as the hydrophilic guide wire, showed no artefacts at all. The remaining material demonstrated minimal artefacts, which did not affect the image quality.
Conclusions: The Uro Dyna-CT can be used for all interventional endourological procedures using the common armamentarium and instruments without significant limitation of image quality. There are only minor limitations according a PCNL working sheath and the rigid URS. These instruments should be removed out of the examination field before performing the computed tomography and be replaced afterwards by using a safety wire.