MSCT上肢静脉直接成像技术的应用

The application of MSCT in upper limb vein direct imaging

目的探讨多层螺旋CT（MSCT）成像技术在上肢CT静脉血管成像中的诊断价值。方法回顾性分析56例行上肢CT静脉血管成像患者的检查资料，并对上肢静脉血管采用容积再现、最大密度投影、多平面重组、曲面重建等多种方式后处理，选定A、B、C（肱骨内外髁连线向近心侧5cm处头静脉和肱静脉的轴位图像；肱骨内外髁连线向近心侧8cm处头静脉和肱静脉的轴位图像；锁骨下静脉的轴位图像）层面分别测量管腔内CT值。测量数据采用SPSS17．0统计软件包分析，对上肢静脉选定层面的静脉管腔内测量的数据采用单因素方差分析，以P〈0．05表示差异有统计学意义。结果56例完成MSCT上肢静脉直接成像的患者中，右上肢发现病变14例，左上肢21例，阳性率为62．5％（35／56），同期行彩色多普勒超声检查，阳性率为58．9％（33／56）。肱骨内外髁连线5cm处各测量位置中静脉管腔内CT值的差异无统计学意义（肱静脉管腔：F=0．004，P〉0．05；头静脉管腔：F=0．102，P〉0．05）。肱骨内外髁连线8cm处各测量位置中静脉管腔内CT值的差异无统计学意义（肱静脉管腔：F=0．007，P〉0．05；头静脉管腔：F=2．271，P〉0．05）。锁骨下静脉层面各测量点之间的CT值差异无统计学意义（F=0．001，P〉0．05）。统计结果提示顺静脉血管方向不同位置静脉管腔内对比剂充盈均匀。上肢静脉远端主干管腔内对比剂浓度高于近心端管腔内对比剂浓度，各层面之间CT值的差异有统计学意义（F=1441．52，P〈0．05）。提示顺静脉血流方向对比剂浓度逐渐减低。结论MSCT上肢静脉直接成像的优势在于可以较大范围显示上肢静脉全程，清晰显示侧支循环，明确血管狭窄、阻塞的原因，了解周围结构情况，辨别血栓形成时间等。该技术相对安全方便、创伤小，减少了碘对比剂用量，减轻了患者的经济负担。应用该技术能提高上肢静脉血栓的诊断率，为临床选择适当的治疗方法提供了可靠的依据。

Objective To discuss the diagnostic value of multi-slice computed tomography （MSCT） as an imaging technique used for upper vein angiography. Methods A total of 56 cases were referred for upper limb vein check by MSCT from June 2010 to March 2012. The veins were scanned by using the LightSpeed 16 computed tomography（CT） scanner and reconstructed by using volume rendering, maximum intensity projection, multi-planner formation, and curve planner reformation. Three different layers were selected to measure the CT value of A, B, and C （i.e., the axial image of the cephalic and brachial veins between condyles of the humerus at 5 and 8 cm and the axial image of the subclavian vein）. Statistical analysis was conducted by using SPSS 17.0, whereas one-way ANOVA F test was used to analyze the measured CT value （P〈0.05 was considered statistically significant）. Results Out of 56 patients, 14 cases of right upper limb and 21 cases of left upper limb were detected to have deep vein thrombosis. That is, 62.5% （35/56） of the cases were detected by MSCT as compared with 58.9% （33/56） of the cases detected by color Doppler. The CT value of the axial image of the brachial and cephalic veins between condyles of the humerus approximately 5 and 8 cm near the heart was P〉0.05, whereas that of the axial image of the subclavian vein was P〉0.05 （F=0.001）. In different layers of vein filled with contrast medium, the CT values were uniform and the differences of the values exhibited no statistical significance between different layers. The contrast medium concentration in the distal part of the upper limb vein was higher than that near the heart, and the differences of the CT values exhibited statistical significance between different layers （F=1441.52, P〈0.05）. Conclusions In conclusion, the MSCT is a superior technology for upper limb vein imaging because it is able to show the upper limb in an extensive range, display the collateral circulation clearly, identify the causes of hemadostenosis, and predict the occurrence of thrombogenesis. Simultaneously, this technology significantly reduces the dosage of iodine contrast agent, lowers the economic burden of patients, improves the rate of correct diagnosis for lesions, and provides reliable bases for selecting correct methods of treatment in clinics.