Preliminary study of lung iodine map by dual-energy CT after inhalation of Iodine gas in rabbits

Objective To study the feasibility of pulmonary ventilation imaging by dual-source CT(DSCT) after inhalation of Iodine gas in rabbits. Methods A total of 18 experimental rabbits were divided into group 1(1/3),group 2(1/2),and group 3(2/3) according to the proportion of inhaled Iohexol(300 mgI/ml) and normal saline,with 6 in each group.The intraperitoneal anesthesia was performed with 15% chloral hydrate (1 kg/ml) in a fasting state.The marginal ear vein was then opened.Sumianxin Ⅱ(1 kg/0.5 ml) was used for additional venous anesthesia in order to reach an ideal state.The iodine gas with different concentration was aerosol inhaled by the rabbits under anesthesia for DSCT scanning.After the post-processing of the DSCT images,the iodine imaging was obtained for the subjective and objective evaluation. Results The subjective rating of imaging qualities was consistently preferable(Kappa=0.786).The total scores in the three groups were 3.25±0.5,4.40±0.44,and 4.20±0.40,respectively.Group 2 had the highest total and subjective scores.The comparison of objective rating between group 1 and group 2 was statistically significant(P<0.05),while between group 2 and group 3 was not statistically significant (P>0.05).Group 2 (one iohexol plus two saline) was the best concentration for DSCT imaging;150 s,210 s and 270 s after the aerosol inhalation were the best phases for observation.The distribution of iodine in the lung was generally uniform for this group,with all pictures rating above 3. Conclusion It is feasible to study the rabbit pulmonary ventilation by aerosol inhaling iodine gas DSCT.