64层CT增强扫描对胃癌患者胃供血动脉的显示

Preoperative assessment of gastric artery in patients with gastric cancer by CT angiography on 64-slice spiral CT

目的探讨64层CT增强扫描对胃癌患者胃供血动脉的显示及血管变异的检出情况。方法回顾性分析行CT检查的连续66例胃癌患者资料。CT扫描根据目标血管管径及跨层走行情况，调节滑块间距得到胃供血动脉薄层滑块最大密度投影图像（STS—MIP），4周后利用血管追踪生长技术获得同一组病例的三维容积重组图像（AVVR）。分析胃的直接和间接供血动脉显示率及来源。采用McNemar检验（精确概率法）比较STS—MIP、AVVR对胃供血动脉的显示率，采用独立样本t检验比较AVVR重组上胃供血动脉显示与动脉强化CT值的关系，分析血管分支变异情况。结果AVVR及STS—MIP对胃间接供血动脉的显示率均达到100％（66／66）。对胃左动脉（LGA）和胃网膜右动脉（RGEA）的显示率分别为98．5％（65／66）、100．0％（66／66）及97．0％（64／66）、100．0％（66／66）；AVVR对胃右动脉（RGA）、胃网膜左动脉（LGEA）、胃短动脉（SGA）及胃后动脉（PGA）的显示率分别为68．2％（45／66）、53．0％（35／66）、7．6％（5／66）和18．2％（12／66），低fSTS—MIP的显示率，分别为98．5％（65／66）、97．0％（64／66）、59．1％（39／66）和63．6％（42／66），差异有统计学意义（P〈0．01）。采用AVVR重组方法，显示的LGEA、RGEA及SGA分别为35、64和5支，腹腔干强化CT值分别为（272±44）、（256±44）和（298±39）}IU，未显示的上述血管支数分别为31、2、61支，腹腔干强化CT值分别为（229±42）、（141±26）和（249±47）HU，差异有统计学意义（t值分别为4．043、3．641和2．278，P值均〈0．05）。检出迷走肝左动脉13例（发生率19．7％），腹腔干大血管分支变异7例（变异率10．6％）。结论64层CT可清晰显示胃周供血动脉及其相关变异，为胃癌术前方案的制定提供参考。

Objective To evaluate the efficacy of different three-dimensional CTA methods on 64-slice sprial CT in the preoperative assessment of gastric arteries and their variations. Methods Sixty-six consecutive patients with gastric cancer who underwent 64-slice spiral CT examinations preoperatively were retrospectively studied. To get the STS-MIP images, the thickness of slab was adjusted according to the inner diameter of targeted blood vessels and their cress-layer distribution. After four weeks, the AVVR images of all cases was got by the auto-vessel technique. The demonstration rates and origins of the direct and indirect feeding arteries were analyzed on AVVR and STS-MIP. McNemar tests were used to compare the detection rates of gastric feeding arteries by STS-MIP and AVVR. The relationship between CT value and display rate of vessels was analyzed using independent-samples t test. The variations of blood vessels were analyzed. Results The display rate of indirect feeding arteries were all 100% （66/66） by STS-MIP and AVVR. The display rates of left gastric artery （LGA） and right gastroepiploic artery （RGEA） were 98.5% （65/66）, 100. 0% （66/66） and 97. 0% （ 64/66）, 100. 0% （ 66/66 ） by STS-MIP and AVVR respectively. The display rates of right gastric artery （ RGA）, left gastroepiploic artery （ LGEA）, short gastric artery （SGA） and posterior gastric artery （PGA） by AVVR were lower than those of STS-MIP with statistical significances[ RGA：68.2% （45/66） vs. 98.5% （65/66）, P 〈0. 01 ;LGEA：53.0% （35/66） vs. 97.0% （64/66）, P 〈0. 01 ; SGA： 7.6% （5/66） vs. 59. 1% （ 39/66）, P 〈 0. 01 ; PGA： 18.2% （12/66） vs. 63.6% （42/66） , P 〈0.01 ]. The demonstration rates of LGEA, RGEA and SGA increased accompanied with the increasing of CT value in celiac axis （ LGEA ： 35 cases displayed with mean CT value of （272 ± 44） HU, 31 cases did not display with mean CT value of （ 229 ± 42） HU, t = 4. 043, P 〈 0. 01 ; RGEA ： 64 cases displayed with mean CT value of （256 ± 44）HU, 2 cases did not display with mean CT value of （ 141 ±26）HU, t =3. 641, P 〈0. 01 ; SGA：5 cases displayed with mean CT value of （298 ±39） ,61 cases did not display with mean CT value of （249 ± 47 ）HU ,t = 2. 278, P 〈 0. 01 ）. Thirteen cases （19. 7% ） with accessory left hepatic artery were identified, and seven cases （10. 6% ） with celiac axis variances were depicted. Conclusion 64-slice spiral CT can clearly demonstrate gastric feeding arteries and related variations, which may provide useful information for the operation of gastric cancer.