【摘要】 目的探讨宝石能谱CT在降低肾动脉CT血管成像(CTA)对比剂浓度和用量中的应用价值。方法50例临床怀疑肾血管源性高血压患者行肾动脉CTA,随机分为两组,两组对比剂用量均为1 ml/kg,其中26例采用传统模式扫描,其对比剂浓度为350 mgI/ml;另一组(24例)采用宝石能谱CT扫描模式,其对比剂浓度稀释一半,为175 mgI/ml,选取能谱CT组肾动脉和肌肉之间具有最佳对比噪声比(CNR)的单能量图像,比较其与传统图像肾动脉CT值及CNR、背景肌肉噪声及主观评分间的差异。结果能谱CT成像所用对比剂浓度较传统CT成像减少了一半(175 mgI/ml vs 350 mgI/ml,P<0.0001),所用碘含量也明显下降(11.96 gI vs 25.63 gI,P<0.0001)。能谱CT成像所得最佳单能量图像上,肾动脉CT值明显高于传统模式成像图像,而两组的CNR、主观评分及剂量长度乘积之间差异无统计学意义。结论能谱CT成像能够有效降低肾动脉CTA所需对比剂浓度及用量,可在临床尤其是肾动脉不全患者中推荐使用。更多还原

【Abstract】 Objective To investigate the utility of gemstone spectral renal CT angiography(CTA) for reducing contrast medium concentration and iodine load.Methods 50 consecutive patients with suspected renal vascular hypertension were divided into two groups randomly.26 patients of group A underwent conventional renal CTA with contrast medium concentration at 350 mgI/ml(n=26) and 24 patients of group B underwent spectral renal CTA with contrast medium concentration at 175mgI/ml(n=24).A set of monochromatic images from 40-140keV were generated from the spectral renal CTA,and from which an optimal energy level was selected for obtaining the best contrast-noise-ratio(CNR) for the abdominal aorta at the renal artery level relative to the erector spine muscle.The CT value and CNR of the bilateral renal arteries,background noise were compared between two groups.Data were analyzed using student T-test by SAS statistical analysis software.Results Compared with conventional renal CTA,there was a half reduction for the contrast medium concentration of spectral renal CTA(175 mgI/ml vs 350 Img/ml,P<0.0001),and the iodine load also showed significant reduction(11.96 gI vs 25.63 gI,P<0.0001).mean CT value of renal arteries at optimal CNR monochromatic images was significantly higher than that of conventional images,while the CNR and subjective scores of renal arteries,and dose length product of both groups showed no statistical difference.Conclusion Spectral renal CTA can effectively reduce the contrast medium concentration and iodine load required,and should be a recommended choice for patients who have underlying renal function impairment.更多还原