双源CT三低扫描模式在头颈部血管造影中的应用价值

目的 探讨三低低管电压、低剂量及低浓度对比剂、低注射速率的扫描模式在头颈部CT血管造影中的临床应用价值。方法 选取2015年6月至2015年11月安庆市立医院确诊或怀疑为头颈部动脉血管病变的患者60例,按照检查排号顺序的奇偶数分成三低组30例和对照组30例,三低组患者行三低头颈CT血管造影（CTA）检查,对比剂碘佛醇（320 mg I/mL）,对比剂剂量为30 mL,注射速率为3 mL/s,管电压70 kV；对照组行常规CTA检查,对比剂碘佛醇（320 mg I/mL）,对比剂剂量为50 mL,注射速率为5 mL/s,管电压120 kV；两组均采用适应统计迭代重建（SAFIRE）技术进行图像重建。比较两组剂量长度乘积（DLP）、辐射剂量（ED）和主动脉弓、基底动脉、两侧颈总动脉末段、两侧颈内动脉C1段、两侧大脑中动脉M1段CT值平均值以及其信号噪声比和对比噪声比；采用Kappa一致性检验比较两组图像质量评分。结果 三低组辐射剂量（ED）平均值（0.24±0.02） mGy]低于对照组（2.63±0.19） mGy],差异有统计学意义（P<0.05）。三低组DLP均值为（102.00±8.12） mGy·cm],对照组为（1 145.12±81.03） mGy·cm],两组差异有统计学意义（P<0.05）。三低组DLP均值低于对照组,两组差异有统计学意义（P<0.05）,其信号噪声比、对比噪声比差异无统计学意义（P>0.05）。两组图像质量主观评分差异无统计学意义（Kappa=0.781）。主动脉弓、基底动脉、两侧颈总动脉末段、两侧颈内动脉C1段、两侧大脑中动脉M1段CT值三低组较对照组高,差异有统计学意义（P<0.05）,两组信号噪声比、对比噪声比差异无统计学意义（P>0.05）。结论 70 kV管电压、低剂量及低浓度对比剂、低注射速率三低头颈部CTA检查所得图像能够满足诊断需求,同时降低了辐射剂量和对比剂用量,值得临床应用与推广。

Application valueof three-low scan mode inhead and neck dual-source CTangiography

Objective To evaluate the clinical value of scanmodewith low tube voltage, low dose andconcentrationcontrast media, low injection rate in the head and neckCT angiography(CTA). Methods 60 patients with diagnosed or suspected head and neck arterial diseases,ever treated in ourhospital from Jun 2015 to Nov 2015, were selected and divided into two groups according to oddand even number of theirchecking sequence, 30 cases in each group. Patients in the studygroup underwenthead and neck CTA in the three-low scanmode, with 70 kV tube voltage and30 mL contrast agent ioversol(320 mgI/mL) in 3 mL/s injection rate. And patients in the control group were performed the conventional head and neck CTA, with 120 kV tube voltage and 50 mL contrast agent ioversol (320 mgI/mL) in 5 mL/sinjection rate. After image reconstructionvia adaptive statistical iterative reconstruction(ASIR), the dose-length product(DLP), effective dose(ED), and averageCT values ofaortic arch andbilateral basilar arteries, end of carotid arteries, C1 segment of internal carotid arteries, M1 segment of middle cerebral arteries, together withsignal-to-noise ratio(SNR) and contrast-to-noise ratio(CNR)between the two groups were compared. The scores ofimage qualitiesbetween the two groups were compared with Kappa consistencytest.Results Thereweresignificantdifferencesbetweenthetwogroupsinthe average values of ED(0.24±0.02) mGy vs (2.63±0.19) mGy;P<0.01] and DLP(102.00±8.12) mGy·cm vs (1 145.12±81.03) mGy·cm;P<0.01], but differences in the SNR and CNR between them was of no significance (P>0.05). The subjective scores of image qualities between them also had no significant difference (Kappa=0.781). The CT values of aortic arch and bilateral basilar arteries, end of carotid arteries, C1 segment of internal carotid arteries, M1 segment of middle cerebral arteries in the study group were significantly higher than those in the controlgroup (P<0.05), but no significant difference was found between them in the SNR and CNR (P>0.05). Conclusion Application ofhead and neckCTA with70 kV tube voltage, low dose andconcentrationcontrast media andlow injection ratecould provide satisfactoryimages for clinical diagnosisand would reduce radiation exposure and contrast administration, which is worthy of clinical expansion.