CO₂ Splenoportography

Objectives: To evaluate the usefulness and safety of CO2 splenoportography(CO2-SP) by comparing it with 3-dimensional dynamic contrast-enhanced magnetic resonance angiography(3D DCE MRA) and transarterial portography(TAP).Methods: 35 patients underwent three kinds of portography. Vital signs, electrocardiogram and saturation of percutaneous blood oxygen(SpO2) were monitored. Patients were questioned about discomfort during the examinations. The clinical value of CO2-SP, 3D DCE MRA and TAP was analyzed and compared, including: (1) the imaging quality of portal vein; (2) the patency of the portal vein; (3) the distribution and extent of collaterals.Results: Transient slight adverse reactions of CO2-SP were presented in 18 cases(51%). The total score of imaging quality of the portal vein shown by CO2-SP, 3D DCE MRA and TAP was 226, 196 and 167 respectively(F=9.49,P〈0.05). Overall sensitivity, specificity and accuracy for disclosing the patency of the portal vein were 96.4%, 97.9% and 97.7% for CO2-SP, 100%, 97.2% and 96.6% for 3D DCE MRA and 96.4%, 94.6% and 94.9% for TAP, respectively. Differences between the imaging methods were not statistically significant. The discordant findings of three methods mainly manifests the discrepancy of the degree of stenosis of portal vein and it may be exaggerated by 3D DCE MRA and TAP. Collaterals displayed by CO2-SP, 3D DCE MRA and TAP were 97%, 94% and 79% respectively(x2=0.697,P〉0.05).Conclusions: (1) CO2-SP with fine-needle appeared to be brief, safe and minimally invasive. (2) The imaging quality of portal vein with CO2-SP is superior to that with 3D DCE MRA and TAP. (3) CO2-SP can accurately display the portal venous pateney and existence of varices, especially in aspect of the degree of the portal venous pateney and small varices.