vHP法在主动脉、冠状动脉及肺动脉一站式成像中的应用研究

目的：探讨320排容积CT可变螺距法（vHP）在急性胸痛患者全主动脉、冠状动脉及肺动脉一站式成像中的临床应用价值。方法：以30例不明原因的急性胸痛患者为实验组，行320排容积CTvHP法扫描：主动脉弓上缘至心底水平采用小螺距心电门控，心底至髂动脉水平采用大螺距不加心电门控。以30例非心电门控大螺距全主动脉320排容积CT扫描患者作为对照组，比较两组的图像质量、辐射剂量以及对比剂使用量。结果：实验组图像对主动脉瓣及主动脉根部的可诊断率（100％，30／30）明显高于对照组（30％，9／30）；所有对照组图像对冠状动脉均无法评价，实验组冠状动脉图像的可诊断率达98％；两组图像对肺动脉的可诊断率差异无统计学意义（P〉0．05）。实验组每例患者的辐射剂量（1131．73±58．08）mGy·cm]稍高于对照组（1102．67±70．29）mGy·cm]，两组间差异无统计学意义（P〉0．05）；实验组中每例患者的对比剂用量（96．07±5．62）mL]略高于对照组（76．00±5．96）mL]，差异有统计学意义（P〈0．05）。结论：vHP扫描法可以在不明显增加辐射剂量的前提下一次完成急性胸痛患者主动脉、冠状动脉及肺动脉的扫描，并可减少对比剂的用量，对于进行胸痛患者尽早明确诊断有一定的应用价值。

Application of variable helical pitch for whole imaging of aorta,coronary and pulmonary arteries

Objective：To explore the value of whole imaging of aorta,coronary arteries,and pulmonary arteries by u- sing variable helical pitch （vHP） method of 320-slice volume CT. Methods： 30 unexplained patients with acute chest pain from our hospital were grouped as the experimental group by vHP scanningl Small pitch ECG-gating CT angiography were performed from the upper edge of the aortic arch to the bottom of the heart, while big pitch without ECG-gating were per formed from the bottom of the heart to the level of iliac artery. The other 30 patients who were scanned by big pitch without ECG-gating for the whole aorta were placed as the control group. The image quality, radiation dose and contrast medium were recorded, and the statistical analysis was performed. Results：The diagnosis rate of the aortic valve and root for the experimental group （100% ,30/30） was higher than that of the control group （30%,9/30）. All the coronary arteries of the control group could not be evaluated,and the diagnosis rate of coronary arteries for the experimental group was 98%. There was no significant difference for the diagnosis of pulmonary arteries and radiation dose between the two groups. The contrast medium volume of the experimental group （96.07±5.62）mL] was higher than that E（76.00±5.96）mL] of the control group （P〈0.05）. Conclusion：The vHP method can obtain the whole image of aorta, coronary, and pulmonary arte ries by only one scan without obvious increasing of the radiation dose, and the volume of contrast medium can be reduced, so it can be used as a valuable method for the early diagnosis of acute chest pain.