低剂量间接法CT静脉成像在下肢静脉曲张中的价值研究

Indirect CT venography in varicose vein of lower limbs:a retrospective study

目的:探讨间接法CT静脉成像(CTV)在下肢静脉曲张中的可行性和价值研究。方法:本研究收集因下肢静脉曲张而准备行介入或手术治疗的患者共37例(F/M,21/16,年龄29~65岁)行下肢CTV成像,所有原始图像均进行血管重建。由两名放射科医师分别对轴位、VR和MPR图像进行综合评价,其中量化参数指标为血管强化程度,包括大隐静脉(GSV)和VV的CT值,信噪比(SNR)和对比噪声比(CNR),并记录两者的主观图像质量评分。将直径>2 mm的穿支静脉标记,取P<0.05有统计学意义。结果:37例下肢静脉曲张患者患肢为单侧者23例,双侧者14例。所有患者的GSV显示均达到诊断要求,且GSV近端与静脉曲张的客观评价指标比较无统计学差异,平均SI,SNR和CNR分别为(121.7±15.9)vs.(124.6±20.3),(8.97±2.16)vs.(9.01±3.02),(3.98±1.99)vs.(4.06±2.17)。主观评价指标中,图像质量好为27例(73.4%),一般为9例(24.3%),1例(2.3%)图像质量差。共14支交通静脉被检出,平均直径为(2.97±0.92)mm,并在后续手术中证实。结论:间接法下肢CTV成像可以显示曲张静脉的回流路径,对穿支静脉的显示具有可行性,具有术前指导意义。

Objective： To investigate the clinical value of indirect CT venography （CTV） in varicose veins （VV） ot lower limbs. Methods： This retrospective study has been approved by the hospital institutional review board. Thirty-seven patients（F/ M, 21/16, age range 29-65 years） diagnosed as VV were recruited in this study, and they were performed with indirect CTV in lower limbs. Two radiologists reviewed all the images, including axial, MPR and 3D volume rendering（VR）. Quantitative in- dexes were compared, including signal intensity（SI） of great saphenous vein（GSV） and VV, the signal-to-noise ratio（SNR） and contrast-to-noise ratio （CNR）. While subjective indexes were performed with a 3-point scale. Perforator veins larger than 2 mm were marked, and statistical analysis was performed. Results： All GSV were demonstrated in 37 patients, including 23 unilat- eral and 14 bilateral VV. Quantitative indexes demonstrate no statistical significance between the proximal point in GSV and VV, including SI, SNR and CNR（119±17.2 vs. 123.4±21.4）, （9.31±2.68 vs. 9.52±3.22）, （3.98±1.99 vs. 4.06±2.17）, respectively. For subjective image quality, 27（73.0%） were excellent, 9（24.3%） fair and 1（2.7%） poor. Fourteen perforator veins were detect- ed, and the mean diameter of perforator veins marked by CTV was （2.97±0.92） mm, which were ligated during the surgery thereafter. Conclusion： Indirect CTV demonstrates feasibility in diagnosis of VV in lower extremities, especially for perforating veins, which is important for preoperative assessment.