Feasibility of MSCT portal vein imaging with 80 kV combined iterative method

Objective: To explore the feasibility and image quality of MSCT portal vein (PV) imaging with low-voltage. Methods: The consecutive 31 patients were enrolled in the study. Ninety milliliter omnipaque (350 mg I/ml) with the rate of 3 ml/s was administrated through the median cubital vein. The arterial (120 kV, 150 mAs) and PV (80 kV, 120 mAs) phase scans were undertaken with a Philips Brilliance iCT scanner. The CTDI_vol and DLP were stored and the effective dose (E) was calculated. Four PV image series were reconstructed with (A) FBP + smooth, (B) FBP + standard, (C) iDose⁴-4 + standard, and (D) iDose⁴-6 + standard algorithm. The maximum intensity projection, volume rendering and multiplanar reformation of portal vein were conducted on a workstation. The CT values of ROI of the aorta, PV, and liver parenchyma were measured, and the SD was considered as the noise. Two experienced radiologists and one technician together reviewed the images. Results: The DLP and E was significantly smaller in PV phases than that in arterial phases [low-dose:(81.23±7.46) mGy·cm, (1.22±0.11) mSv; routine dose: (353.45±31.46) mGy·cm, (5.30±0.47) mSv, F = 2197.23, P < 0.05). The noises were different among the groups with that smallest in group D and largest in group B. All PV images were sufficient for diagnosis but those in the group C and D were better. Conclusions: The hybrid low-dose MSCT PV imaging with 80 kV combined iterative method would be feasible. (authors)