Use of Cone-Beam Computed Tomography (CBCT) for Targeting the Portal Vein in Transjugular Intrahepatic Portosystemic Shunt (TIPS) Procedures: Comparison of Low-Dose with Standard-Dose CBCT

Background: A transjugular intrahepatic portosystemic shunt (TIPS) is a common treatment for patients with portal hypertension. In these patients, the portal vein can be punctured under the guidance of cone-beam computed tomography (CBCT). Objectives: To compare standard-dose (SD) CBCT with low-dose (LD) CBCT, as three-dimensional (3D) intraprocedural guidance for transhepatic puncture in TIPS placement, in terms of image quality, radiation dose, technical success, and complications. Materials and Methods: A total of 44 patients were retrospectively enrolled in this study. Eighteen patients underwent LD-CBCT, while 26 patients underwent SD-CBCT for guiding the portal vein puncture. A quantitative assessment of image quality was performed by calculating the contrast-to-noise ratio (CNR) of the hepatic portal vein. This analysis was based on a five-point vascular visualization scale (VVS), ranging from optimal (score = 1) to non-diagnostic (score = 5), while a three-point Likert scale was used for motion artifacts (1 = no motion artifacts, 3 = blurred). Image streak artifacts were also rated from one to three, based on the image quality results. Technical success was also investigated, including the number of puncture attempts, time to successful portal vein access, and radiation dose of the TIPS procedure. Results: Based on the results, TIPS could be placed successfully in all cases. Neither VVS (LD-CBCT VVS: 2.78, SD-CBCT VVS: 2.54; P = 0.467), nor the procedure time showed any significant differences between the groups (LD-CBCT: 48.3 min, SD-CBCT: 40.2 min; P = 0.45). Moreover, the objective evaluation of image quality indicated the lower quality of LD-CBCT images; however, the difference was not statistically significant (LD-CBCT CNR: 1.1 ± 0.76, SD-CBCT CNR: 1.3 ± 1.1; P = 0.5). The median number of puncture attempts was the same for SD-CBCT and LD-CBCT (n = 3; range: 1 - 6). Also, the mean dose area product (DAP) was significantly lower in LD-CBCT as compared to SD-CBCT (LD-CBCT: 2733 ± 848 µGm2, SD-CBCT: 6119 ± 1677 µGm2; P < 0.0001). The total DAP was significantly lower using LD-CBCT (LD-CBCT: 14831 ± 9299 µGm2, SD-CBCT: 20985 ± 10127 µGm2; P = 0.047). Conclusion: Both SD-CBCT and LD-CBCT provided successful 3D guidance for portal vein puncture during TIPS creation. Although these methods did not differ significantly in terms of image quality, complications, or number of puncture attempts, LD-CBCT significantly reduced the radiation dose.