不同浓度对比剂在正常兔脑CT灌注成像中的对照实验研究

目的 评价低速团注高浓度对比剂在兔脑CT灌注成像中的效果.方法 12只新西兰白兔随机分为3组,每组分别使用A方案(典迈伦400 mgI/ml,流率1.0 ml/s);B方案(400 mgI/ml,流率0.5 ml/s);C方案(300 mgI/ml,流率1.0 ml/s)行脑CT灌注成像,每次注射对比剂含碘量为0.5 g/kg体重.对比各方案脑CBF、CBV、MTT、灌注曲线峰值出现时间及峰值时大脑中动脉的CT值.结果 A、B、C三种方案测得脑CBF平均值分别为(69.8±11.4)、(72.2±12.8)、(74.8±10.3)ml/(min·100 g).CBV平均值分别为(2.5±0.3)ml/100 g,(2.7±0.2)ml/100g,(2.6±0.3)ml/100g.MTT平均值分别为(2.27±0.19)s,(2.30±0.26)s,(2.55±0.30)s,三种方案各灌注参数之间差异无统计学意义.灌注曲线峰值出现时间分别为4 s、5 s、5 s.大脑中动脉增强峰值分别为(193.5±5.1)、(164.7±5.2)、(163.0±7.1)HU,A方案高于B、C方案,B、C方案之间差异无统计学意义.结论 兔脑CT灌注成像中使用高浓度对比剂,可以降低注射速度而对灌注参数结果无明显影响;注射速度相同情况下,应用高浓度对比剂可使血管显示更清晰.

An experimental study of different concentration contrast media in cerebral CT perfusion imaging of healthy rabbits

Objective To evaluate the effects of high-concentration contrast media (400 mgI/ml) with low flow rate on the cerebral CT perfusion imaging of healthy rabbits. Methods Twelve New Zealand white rabbits were randomly separated into three groups. They underwent cerebral CT perfusion imaging with protocol A (Iomeprol: 400 mgI/ml, flow rate: 1.0 ml/s), protocol B (Iomeprol: 400 mgI/ml, flow rate: 0.5 ml/s), protocol C (300 mgI/ml, flow rate: 1.0 ml/s). The total iodine for each injection was 0.5 g/kg. CBFs, CBVs, MTTs, TTPs and CT values of middle cerebral artery of each protocol were acquired and compared statistically. Results The mean CBFs of three protocol were (69.8±11.4), (72.2±12.8), and (74.8±10.3)ml/(min·100 g) respectively (P=0.759). The mean CBVs of three protocol were (2.5±0.3)ml/100 g, (2.7±0.2)ml/100 g, (2.6±0.3)ml/100 g, respectively. The mean MTTs of three protocol were (2.27±0.19)s, (2.30±0.26)s, (2.55±0.30)s, respectively. The TTPs of three protocol were 4 s, 5 s, 5 s respectively. And mean CT value ( HU) of middle cerebral artery at peak time was higher than that of protocol B ( HU) and protocol C ( HU), but the difference between protocol B and protocol C was not significant. Conclusion Cerebral CT perfusion imaging of healthy rabbits using high-concentration contrast media with low flow rate will not affect the perfusion parameters. Under same injection rate, high-concentration contrast media may improve the display of vessels.