Streak artefacts in Computed Tomography Urography: Comparative evaluation between two different iodinated contrast media.

INTRODUCTION: The objective of this study was to compare the frequency and entity, in computed tomography (CT) urography, of streak artefacts on the urinary tract generated by two contrast agents with a different iodine concentration and osmolarity.

METHODS: Computed tomography scans including an excretory renal phase, performed on adult subjects in the period May-July 2020, were retrospectively evaluated in consensus by three expert radiologists, to detect any streak artefacts located in the urinary tract. Patients were administered either 1.6 mL/kg of Iodixanol 320 mgI/mL or 1.3 mL/kg of Iomeprol 400 mgI/mL.

RESULTS: In total, 144 CT scans were analysed, subdivided into two groups administered either Iodixanol (71/144 (49.3%) patients) or Iomeprol (73/144 (50.7%) patients). In 41% cases, no beam hardening artefacts were found; among these, 12/59 (20.3%) patients had received Iodixanol and 47/59 (79.7%) Iomeprol. In the Iodixanol group, the mean contrast density on the renal pelvis was 2565.6 HU and streak artefacts occurred in 59/71 cases (83.1%); in 33/59 (55.9%) cases, the artefacts were marked, and in 26/59 (44.1%) minimal. In the Iomeprol group, the mean contrast density on the renal pelvis was 1666 HU and streak artefacts occurred in 26/73 cases (35.6%); in 7/26 (27%) cases, the artefacts were marked and in 19/26 (73%) minimal.

CONCLUSION: The study data demonstrate a significant difference in the attenuation values of iodine urine in the excretory system between the Iodixanol and Iomeprol group. Iodixanol induced a higher frequency and burden of artefacts, compared to Iomeprol.