低管电压间接法下肢CT静脉成像在静脉曲张术前评价的价值研究
Low Tube Voltage Indirect CT Venography (CTV) in Lower limbs:A Potential Guidance for Varicose Vein in Preoperative Assessment
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摘要: 目的:探讨低管电压间接法下肢CT静脉成像(CTV)在静脉曲张术前评价的临床价值研究。材料和方法:本研究通过医院伦理委员会批准。55名疑诊为下肢静脉曲张患者(F/M,23/32,年龄范围15~77岁)纳入本研究。所有患者均行下肢CTV,将原始图像进行MPR和VR重建,对图像质量评价。客观评价指标为大隐静脉(GSV)和曲张静脉(VV)的信号强度(SI),信噪比(SNR)和对比噪声比(CNR)。主观评分由2名放射科医师阅片评价,并记录直径大于2mm的交通静脉和最终辐射剂量。结果:44名患者(F/M,17/27,年龄范围36~67岁)诊断为下肢静脉曲张,其中单侧31名,双侧13名,其他患者中2名诊断为动静脉瘘,3名诊断为静脉发育不全,6名诊断为下肢静脉血栓。所有44名下肢静脉曲张患者的GSV全程显示,GSV近端与VV的客观评价指标比较无统计学差异,平均SI、SNR、和CNR分别为((122±16.4)HUVersus(125.9±23.6)HU),(9.62±2.71Versus9.91±3.12),(4.08±2.39Versus4.36±2.81),主观评价指标中,图像质量好35例(79.5%),一般8例,差1例(2.3%)。共22支交通静脉被检出,平均直径为(3.21±0.87)mm,并在后续手术中证实。平均辐射剂量(804.7±96.7)mGy·cm。结论:低管电压迭代重建间接法下肢CTV在静脉曲张的应用中,能够以较好的图像质量显示静脉回流路径,并检出交通静脉,有助于术前更完善的评价。Abstract: Purpose: To investigate the feasibility of low tube voltage indirect CT venography (CTV) in superficial venous system in varicose veins (VV) of lower limbs. Materials and Methods: This prospective study has been approved by the hospital institutional review board. Fifty-five consecutively patients (F/M, 23/32, age range 15-77 years) suspicious of varicose veins were recruited in this study. All the patients were performed CT venography (CTV) in lower limbs. The signal intensity (SI) of great saphenous vein (GSV) and varicose vein (VV) was measured, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective image quality of MPR and 3D volume rendering (VR) were assessed by two experienced radiologists using a 3-point scale. Perforator veins larger than 5 mm in the VV were marked. The radiation doses were recorded. Results: Forty-four patients were diagnosed as VV, including 31 unilateral and 13 bilateral VV, while 2 patients with arteriovenous fistula, 3 hypovenosity and 6 deep venous thrombosis. All GSVs in 44 patients were demonstrated the entire length in Low tube voltage CTV. There is no statistical significance in quantitative indexes between the proximal point in GSV and VV, with the mean SI, SNR and CNR (122 ±16.4 Versus (125.9±23.6)HU), (9.62 ±2.71 Versus 9.91 ±3.12), (4.0 ±2.39 Versus 4.36 ±2.81), respectively. For subjective image quality, 35 (79.5%) were excellent, 8 (18.2%) fair and 1 (2.3%) poor. Twenty-two perforator veins were detected in 15 patients, and the mean diameter of perforator veins marked by CTV was 3.21 ±0.87 mm, which were ligated during the surgery thereafter. The mean radiation dose was (804.7 ±96.7)mGy.cm. Conclusions: Low tube voltage indirect CT venography with iterative reconstruction accommodates available image quality for diagnosis of varicose vein in lower extremities, and provides the road map in preoperative assessment, especially for deep-seated perforating veins, which demonstrates the potential ability to navigate the varicose vein surgery.