MR动态增强时间减影灌注成像在周围型肺癌肺动脉血供定性及定量评估中的初步应用

目的 探讨MR动态增强时间减影技术在周围型肺癌肺动脉血供定性及半定量评估中的应用价值。方法 应用MR动态增强时间减影肺灌注成像技术，获取23例经组织学／细胞学确诊的周围型肺癌患者在造影剂增强首过期内的系列图像，在工作站上将强化前后的图像行减影处理，得到肺动脉(PA)期、肺实质(PP)期、肺静脉／降主动脉(DA)期图像，并在时间信号曲线基础上测定癌肿的起始强化时间、峰值时间，以及癌肿在肺动脉灌注期(包括PA期及PP期)及主动脉灌注期(DA期)的强化率，进行定性及部分定量分析。结果 本组23例患者测得三种微循环灌注模式：14例(60．9％)在肺循环期开始强化，在体循环期达到峰值，体循环期强化率较肺循环期高(P＜0.001)，提示癌肿为肺／体循环双重供血，以体循环为主；7例(30．4％)在体循环期开始强化并达到峰值，提示完全为主动脉供血；2例(8．7％)在肺循环期开始强化并达到峰值，提示主要由肺动脉供血。结论 MR动态增强时间减影灌注技术可以对周围型肺癌肺动脉血供进行定性及相对定量评估，作为无创性检查技术具有重要的临床应用价值。

A preliminary application of MR dynamic time-resolved subtracted perfusion imaging to qualitative and partial quantitative evaluation of the blood supply by pulmonary artery in peripheral type lung cancer

Objective To explore the application of MR time resolved subtracted perfusion imaging to qualitatively and partially quantitatively evaluate blood supply by pulmonary artery in patients with peripheral type lung cancer. Methods Twenty three patients with peripheral type lung cancer proved cytologically or/and histologically underwent MR perfusion study. The time resolved subtracted imaging which provided the perfusion images in different phases were performed. First pass time signal intensity curves of pulmonary artery, descending aorta, lung mass were obtained respectively, and start time and peak time of them were compared. The signal enhanced ratio of the masses in pulmonary artery and aorta perfusion phases were calculated respectively. Results Fourteen masses began to enhance during pulmonary circulation phase and reached peak value during systematic circulation phase, and the average signal change ratio during pulmonary circulation phase was much smaller than that during systematic circulation phase, indicating their blood supply came both from pulmonary and systematic blood circulation, but mainly from the latter. Seven masses began to enhance and reached peak value during systematic circulation phase, indicating their blood supply came mainly from systematic blood circulation. Two masses began to enhance and reached peak value during pulmonary circulation phase, indicating their blood supply came mainly from pulmonary blood circulation. Conclusion MR dynamic time resolved subtracted perfusion imaging is feasible to qualitatively and relatively quantitatively evaluate blood supply of pulmonary artery for peripheral type lung cancer.